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SCIENCE PUBLICATION (Publicly available) Risk assessment of chemicals in household products Milestone 1
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REPORT INFORMATION SHEET REPORT TITLE
RISK ASSESSMENT OF CHEMICALS IN HOUSEHOLD PRODUCTS
AUTHORS
LOUIS A TREMBLAY1,2, OLIVIER CHAMPEAU1, LAURA BIESSY1, JOEL BOWATER1, GRANT L NORTHCOTT3 1
CAWTHRON INSTITUTE, NELSON SCHOOL OF BIOLOGICAL SCIENCES, UNIVERSITY OF AUCKLAND 3 NORTHCOTT RESEARCH CONSULTANTS LIMITED, HAMILTON 2
CIBR PUBLICATION NUMBER
04
SIGNED OFF BY
JACQUI HORSWELL DATE
JULY 2013
CONFIDENTIALITY REQUIREMENT
PUBLICLY AVAILABLE
INTELLECTUAL PROPERTY
© CIBR ALL RIGHTS RESERVED. UNLESS PERMITTED BY CONTRACT OR LAW , NO PART OF THIS WORK MAY BE REPRODUCED, STORED OR COPIED IN ANY FORM OR BY ANY MEANS WITHOUT THE EXPRESS PERMISSION OF THE CENTRE FOR INTEGRATED BIOWASTE RESEARCH.
Disclaimer The opinions provided in the Report have been provided in good faith and on the basis that every endeavour has been made to be accurate and not misleading and to exercise reasonable care, skill and judgment. The Ministry for the Environment does not necessarily endorse or support the content of the publication in any way. This work is copyright. The copying, adaptation, or issuing of this work to the public on a non-profit basis is welcomed. No other use of this work is permitted without the prior consent of the copyright holder(s).
EXECUTIVE SUMMARY The ecotoxicology component of the Up-the-Pipe solutions project examined the potential environmental impact of active ingredients found in common household cleaning and personal care products in order to identify harmful chemicals that could potentially be replaced by less harmful alternatives. Septic tank wastes were used as a case study as they are almost specifically used to treat domestic wastewater and as such provide the best opportunity to assess the potential environmental impacts of chemicals commonly used in New Zealand households.
Objectives The objectives of this study were to: select a series of chemicals found in commonly used household products select a representative septic tank system to be studied assess the toxicity of the selected chemicals using standardised bioassay analyses provide a ranking of the risk of the chemicals tested.
Key Results The risk of the selected chemicals was assessed and ranked. To achieve this, a score was attributed based on the toxicity results from this study which were integrated with the physical parameters of the chemicals. The score was then weighted (log P×1, Koc×1, BCF×2, IC50×4) to reflect the potential risk contribution for each parameter. A ranking for each chemical was obtained by adding the sum of the scores. The chemicals were assigned a traffic light system colour according to: green (lowest 1/3 of the score range), yellow (medium 1/3 of the score range) and red (highest 1/3 of the score range). Ranking (weighted scores) is shown in the following table: Category scoring Log P Koc BCF IC50 Benzophenone 3 4 6 8 Bisphenol A 4 4 6 12 Chloroxylenol 3 4 6 16 DEET 3 3 8 4 Diclofenac 5 3 4 8 Octyl-methoxycinnamate 6 5 10 12 2-Phenoxyethanol 2 2 4* 4 2-Phenylphenol 3 5 6 8 Triclosan 5 5 6 12 Chemical
Ranking 21 26 29 18 20 33 12 22 28
*No data available, intermediate value applied
(Refer to appendix C for scores used for each category) This process identified three high risk chemicals, namely the disinfectant chloroxylenol, the UV filter/sunscreen agent octyl-methoxycinnamate, and the antimicrobial chemical trisclosan.
Implications of Results/Conclusions
The levels of some of the selected chemicals in New Zealand domestic waste water effluent samples were comparable to those reported in overseas studies (Drewes et al. 2009). Some of the chemicals tested showed toxicity and the potential to interact with other chemicals by increasing the toxicity in binary mixtures. One sunblock agent and two antimicrobial chemicals showed the highest risk.
Further Work
Future research is necessary to assess the potential toxicity of a wider range of commonly used household chemicals, particularly the long-term chronic impacts (e.g. effects on reproduction) of individual chemicals and mixtures of chemicals. The information from this research can be integrated into life cycle assessment (LCA) processes to determine the environmental impacts of particular product groups or substances found in widely used household products. Continue to engage the community through engagement processes to ensure uptake and implementation of the fuindings (Baker 2012; Baker and Horswell 2012). There is a need to continue to raise awareness around the consequences of using products containing more harmful chemicals. Reducing the level of chemicals released from individual house remains a most efficient way to reduce hazardous substances entering the New Zealand environment. Use the ranking of chemicals approach to offer alternative more sustainable options to consumers so that they can make more informed decisions when buying household and personal care products.
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RISK ASSESSMENT OF CHEMICALS IN HOUSEHOLD PRODUCTS LOUIS A TREMBLAY1,2, OLIVIER CHAMPEAU1, LAURA BIESSY1, JOEL BOWATER1, GRANT L NORTHCOTT3 1 CAWTHRON
INSTITUTE, NELSON UNIVERSITY OF AUCKLAND 3 NORTHCOTT RESEARCH CONSULTANTS LIMITED, HAMILTON 2 SBS,
July 2013
Table of Contents EXECUTIVE SUMMARY ------------------------------------------------------------------------------------------- i Introduction ----------------------------------------------------------------------------------------------------------1 Chemical selection -----------------------------------------------------------------------------------------------2 Selection of the septic tank waste ----------------------------------------------------------------------------4 Methodologies-------------------------------------------------------------------------------------------------------6 Algae -----------------------------------------------------------------------------------------------------------------6 Zebrafish – Fish Embryo Toxicity (FET) test ---------------------------------------------------------------7 Sea urchin embryo-larval development----------------------------------------------------------------------7 Lux bioassay: inhibition of light from lux-gene modified Escherichia coli ----------------------------8 Chemical analysis ------------------------------------------------------------------------------------------------9 Sampling of the domestic wastewater. -------------------------------------------------------------------9 Opito Bay Sewage Company -------------------------------------------------------------------------------9 Wastewater treatment plant influent ----------------------------------------------------------------------9 Kaikoura biosolids ---------------------------------------------------------------------------------------------9 Preparation of waste water samples ----------------------------------------------------------------------9 Solid phase extraction of filtered waste water samples for bioassay analysis ---------------- 10 Solid phase extraction of filtered wastewater samples for chemical analysis ----------------- 10 Accelerated solvent extraction of filtered particulates and biosolids----------------------------- 11 Extraction of accelerated solvent extraction solutions ---------------------------------------------- 11 Instrumental analysis --------------------------------------------------------------------------------------- 12 Results --------------------------------------------------------------------------------------------------------------- 12 Toxicity of the selected chemicals and waste samples using the algal test ------------------- 12 Inhibition of light from lux-gene modified Escherichia coli to assess the effects of binary mixtures -------------------------------------------------------------------------------------------------------- 16 Chemical analysis ------------------------------------------------------------------------------------------- 17 Discussion ---------------------------------------------------------------------------------------------------------- 17 Conclusions -------------------------------------------------------------------------------------------------------- 19 Acknowledgements ---------------------------------------------------------------------------------------------- 20 References---------------------------------------------------------------------------------------------------------- 20 Appendix A --------------------------------------------------------------------------------------------------------- 22
Appendix B --------------------------------------------------------------------------------------------------------- 23 Benzophenone -------------------------------------------------------------------------------------------------- 23 Bisphenol A ------------------------------------------------------------------------------------------------------ 24 Chloroxylenol ---------------------------------------------------------------------------------------------------- 25 DEET -------------------------------------------------------------------------------------------------------------- 26 Diclofenac -------------------------------------------------------------------------------------------------------- 27 4-Methylbenzylidene camphor ------------------------------------------------------------------------------- 28 Octyl methoxycinnamate -------------------------------------------------------------------------------------- 28 2-Phenoxyethanol ---------------------------------------------------------------------------------------------- 30 2-Phenylphenol -------------------------------------------------------------------------------------------------- 31 Triclosan ---------------------------------------------------------------------------------------------------------- 32 Appendix C --------------------------------------------------------------------------------------------------------- 34 Ranking details -------------------------------------------------------------------------------------------------- 34
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Tables and figures Table 1. List and descriptions of the household product chemicals that were studied. ............ 3 Table 2. Summary of the test conditions for the marine green microalgae, Pseudokirchneriella subcapitata bioassay. ................................................................................................................. 6 Table 3. Summary of the test conditions for the fish embryo toxicity (FET) bioassay using zebrafish. 7 Table 4. Summary of the test conditions for the sea urchin bioassay. ..................................... 8 Table 5. Summary of the test conditions for the inhibition of light from lux-gene modified Escherichia coli assay ................................................................................................................ 8 Table 6. Sample information for Opito Bay septic tank and Kaikōura biosolids bioassay extracts. 10 Table 7. Results from the toxicity testing of household chemicals using the freshwater microalgae P subcapitata (with the 95% confidence intervals (CI)). .................................................. 13 Table 8. Results from the toxicity testing of sewage extracts using the freshwater micro-algae P subcapitata (with the 95% confidence intervals (CI)). ............................................................ 13 Table 9. Results from the toxicity testing of bisphenol A and Triclosan using the bacterial luxgene assay (with the 95% confidence intervals (CI)). ............................................................... 16 Table 10. Statistical summary of the concentration (ng/L)a of selected personal care chemicals in New Zealand wastewaters. .................................................................................. 17 Figure 1. Pictures of 24 hr zebrafish embryos. A: healthy embryo; B: coagulated embryo. ..... 7 Figure 2. Toxicity results of the Opito Bay septic tank effluent sample dissolved fraction extract serial dilutions reported as means and standard deviations of the algal growth. * Indicates a statistically difference from the control (p < 0.05). ..................................................................... 14 Figure 3. Toxicity results of the Opito Bay septic tank effluent sample particulate phase extract serial dilutions reported as means and standard deviations of the algal growth. ....................... 14 Figure 4. Toxicity results of the serial dilution samples of the Kaikōura biosolids extract reported as means and standard deviations of the algal growth. * Indicates a statistically difference from the control (p < 0.05). ....................................................................................... 15 Figure 5. The impact of bisphenol A (BPA) and chloroxylenol on the normal development of the sea urchin larvae. A normally developed pluteus is shown on the far left (control). ............. 15 Figure 6. Mean, replicates values (purple dots) and fitted model of the light production by E coli exposed 30 minutes to increasing concentrations of A- Bisphenol A and B- Triclosan. ...... 16 Figure 7. Mean and standard deviations of the percentage of light production by E coli exposed to mixtures of Bisphenol A (BPA) and Triclosan (TCS) related to control. .................. 16
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Introduction The Ministry for the Environment Waste Minimisation Fund ‘Up the Pipe solutions” project builds on the many successful existing partnerships with the Kaikōura District Council, Te Runganga ō Kaikōura and wider community formed through the MBIE Biowastes Research project. The aim of this interdisciplinary project is to increase options and acceptability for beneficial reuse of septic tank sludge which is used as a case study and represents a waste source of importance for both rural and urban communities with limited sewage infrastructure in New Zealand (for example Kerikeri in Northland). It goes back ‘up the pipe’ to involve community members in a research project to better understand and reduce the waste that goes down our drains. The information is intended to assist the development of community-based waste management solutions. The Up-the-Pipe solutions project integrates biophysical and social sciences to raise awareness, characterise behaviours, and providing learning resources that can support behaviour change in the use of household cleaning and personal care products that go down the drain and ultimately end up in the environment. The primary focus of the Up the Pipe solutions project is organic chemicals present in commonly used household products. The use of chemicals is a key component in the maintenance of our standard of living in modern society. With nearly two thirds of the world’s population living in urban areas, cities concentrate multiple human activities and are major contributors of waste by being concentrators, repositories, and emitters of a myriad of chemicals of anthropogenic origin (Diamond and Hodge 2007). Many chemicals are produced from daily domestic activities such as cooking, cleaning, personal grooming, medical care, and gardening. Those contaminants ultimately find their way into the environment through sewage and into the atmosphere where some of them enter stormwater following deposition. A study looked at the contaminants contained in household solid wastes by direct sampling in the UK and included paint, pet products, pharmaceuticals, household cleaners, motor vehicle waste and printer cartridges (Slack et al 2007). Chemicals in use in households are often further grouped into high production volume chemicals (HPVCs). The US National Institutes of Health (NIH) list roughly 2800 compounds in daily (household) use, based on a survey of Material Safety Data Sheets (MSDS) of 7000 household products (US Department of Health and Human Services 2013). There is a very large number of chemicals that can potentially enter our environment. There is limited information on the potential adverse effects of these chemicals in complex mixtures on exposed organisms and on humans and therefore it is challenging to establish relevant risk assessment. It was recently stated that the increasing accumulation of both natural and industrial chemical 1
contaminants in freshwater is one of the key environmental problems facing humanity (Schwarzenbach et al. 2006). The aims of the ecotoxicology component of the project were: To select a group of representative chemicals found in commonly used household products to use a combination of field and laboratory studies to identify the main sources of contaminants including commonly used household products to review the literature to assess chemicals leaching from household plumbing systems to conduct an ecotoxicity assessment of the selected chemicals with standard toxicity tests to provide a risk ranking of the chemicals tested.
Chemical selection An excellent study conducted for the water environment research foundation (WERF) identified household chemicals found in municipal sewage (Drewes et al. 2009). Out of 26 high-production-volume (HPV) household chemicals targeted in this study, 20 compounds were consistently detected in raw influents of full-scale wastewater treatment plants. One of the components of the school questionnaire filled by the Kaikōura High School students specifically asked for the range of products found in their house. Table 1 summarises the 11 key chemicals found in commonly used household products that were selected from the WERF report and from the Kaikōura High School survey (Baker 2012). More chemical and physical details on the chemicals are provided in Appendix B.
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Table 1. List and descriptions of the household product chemicals that were studied. Chemical Property/Products containing the Number products ingredient (only indicative) Benzophenone Used as an odour fixative, a fragrance in 10 soaps, a polymerization inhibitor for styrene, in organic synthesis, and in the manufacture of antihistamines, hypnotics, insecticides, pharmaceuticals, and ultraviolet absorbers. It is found in car wash, and bath and skin care products Propylparaben Preservative, stain remover, hair dye/skin 480 care cream, baby lotion cream, moisturizer, shower gel, body lotion, pet care. 2-Phenoxyethanol Used as a solvent for cellulose acetate 200 and dyes, in inks and resins, as a perfume fixative, as a bactericidal agent, in organic synthesis of plasticizers, germicides and pharmaceuticals, and in insect repellents. Found in shampoo, conditioner, moisturizer, hair colour, pet care (antibacterial) 2-Phenylphenol Used in rubber chemicals, in food 4 packaging, as an intermediate for dyes, and as a food preservative. Commonly used as disinfectant (0.1%) Chloroxylenol Used as an antibacterial, germicide, 10 antiseptic and in mildew prevention. Commonly used in antibacterial soaps and household antiseptics and disinfectant DEET (N,N-diethyl-meta Most common active ingredient in insect 60 toluamide) repellent products (5 to 98%) Octyl methoxycinnamate Sunblock (~8%) (NZCS) 100 4-Methylbenzylidene Sunblock (~3%) (NZCS) 100 camphor Gemfibrozil Lipid regulator Diclofenac sodium salt An analgesic and non-steroidal antiinflammatory drug. Triclosan* Antimicrobial commonly used in soap, lotion and toothpaste. Bisphenol A (4,4Plasticiser widely used and found in Isopropylidenediphenol) epoxy and glue. 3
Selection of the septic tank waste Following discussions with staff from the Kaikōura District Council and Environment Canterbury, it became apparent that there were no suitable septic tank systems that could be readily accessed to conduct this research. There is limited information available on the location and overall status of the septic tanks in the region. Stuart Grant, Chief Executive Officer at Kaikōura District Council, suggested using the Kaikōura municipal biosolids directly. The use of the Kaikōura biosolids provides a good model to assess the fate of chemicals in a representative treatment system and their toxicity. An alternative septic tank system was required and one was identified in the North Island. The Opito Bay Sewage Company (OBSC) services a residential household community at Opito Bay in the Coromandel Peninsula. The sewage scheme was specified as a requirement in the resource consent for the original Ohinau Drive-Thompson Place subdivision development with the goal to minimise the potential impact of septic tank effluents within Opito Bay. The Opito Bay sewage scheme serves 54 individual property titles and a total of 43 properties are currently connected into the scheme. Within these 43 properties there are 6 permanent residents and the remaining properties are used as holiday homes. Occupancy of these holiday properties is estimated to range between two to 10 weeks/annum. Higher rates of occupancy are experienced over key holiday periods including the summer Xmas holidays, Auckland Anniversary, Easter holidays, Queens Birthday weekend, and school holiday periods. The Opito Bay Sewage system provides a combination of septic tank treatment followed by spray irrigation into a commercial forest. Each property operates a septic tank for treatment of their domestic wastewater. Septic tanks connected to the Opito Bay sewage scheme are required to meet a minimum specification. They must have a 4500L capacity, be a two stage design or similar, and be fitted with an outlet effluent filter. Most of the properties linked into the Opito Bay sewage scheme have installed the Humes design two stage septic tank system or brand similar products. A limited number of properties have installed aerated multi-chamber septic tank systems, and some isolate greywater for reuse in toilet flushing and/or garden irrigation. The outlet flow from septic tanks on individual properties is reticulated to a central collection sump and pump station. The combined effluent is pumped up hill to a lined storage pond and is subsequently spray irrigated into a plantation pine forest. The pumping station transfers approximately 4000m3 of septic tank effluent to the storage pond each year. As a result of irregular use and waste input the septic tank treatment systems of holiday homes are notoriously inefficient. These systems often become “starved” of nutrients and are unable to maintain a stable and efficient functioning biomass. When homeowners are in residence the biomass residing in the septic tank systems can become overloaded with the rapid input of waste and the systems are often swamped by a disproportionate volume of greywater, particularly the drainage from showers and dishwashing waste. This combination of irregular nutrient inputs and disproportionate volumes of greywater and 4
kitchen sink liquid waste acts to reduce the degradation efficiency of septic tank treatment. This in turn reduces the ability of septic tank treatment to degrade chemicals present in domestic wastewater, including personal care chemicals and pharmaceutical medicines. These consequences are amplified at peak holiday times when holiday households typically accommodate larger family groups and other temporary guests. Obtaining samples from individual septic tank systems is fraught with difficulty. Most properties operating septic tanks are not able to provide ready access into their tanks which more often than not are buried at depth under the soil surface. Commonly the only evidence for the location of a septic tank system is the covered venting pipe which doesn’t provide suitable access for sampling the septic tank. Another important issue to consider is protecting the privacy of household residents. Some prescribed medications are specific to particular illnesses and their measurement in household waste water provides researchers with intimate knowledge they would otherwise remain ignorant of. Some property owners are suspicious of the intent of research and will not provide access to their treatment systems for the purpose of scientific research. Obtaining access to sample wastewater entering the Opito Bay Sewage Treatment Company overcame these difficulties as the system integrates waste water from numerous properties so individuals cannot be identified, and the sampling point is located on council reserve.
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Methodologies The toxicity of the selected chemicals and waste extracts was assessed using international standard tests. The standard tests were from bacterial, algal and invertebrate models representing different trophic levels.
Algae The freshwater green micro-algae Pseudokirchneriella subcapitata assay is a standardised test (Hall & Golding 1998; ASTM 2004; ISO 2012). During its exponential growing phase, the algae is exposed to dilutions of a test solution under static (i.e. no renewal of the test solutions) but controlled (e.g. constant temperature and salinity) conditions over a period of 72 hours. Over that period the algae can produce several generations and the growth of algae exposed to the test solution is compared to the growth of the control. A test solution is considered toxic when statistically significant, dose-dependent inhibition of algae growth occurs. Details of the test are provided in table 2. Table 2. Summary of the test conditions for the marine green microalgae, Pseudokirchneriella subcapitata bioassay. Test type Static Test duration 72 hr Temperature 24 ± 1C Light intensity 56 μmol/(m2.s) Photoperiod Continuous Test chamber 96-well microplate No. test organisms/ test chamber 1 × 104 /mL No. replicate beakers / sample 4 reps/ sample Test chamber aeration None Endpoint Growth Test acceptability criteria (controls) Growth >16 fold, CV80% Test acceptability criteria (reference Mortality > 30% toxicant)
A
Figure 1.
B
Pictures of 24 hr zebrafish embryos. A: healthy embryo; B: coagulated embryo.
Sea urchin embryo-larval development The sea urchin embryo-larval assay is a widely used and well validated test (ASTM 1998) and has been adapted to the New Zealand native sea urchin Evechinus chloriticus. Briefly, freshly fertilised eggs are exposed to dilutions of the test solution under static conditions (no renewal of the test solution) for a fixed period of 48 hr. At the end of the test, larvae are fixed in a solution of formalin and larvae are numbered. The number of abnormal pluteus larvae in test solution gives an indication on embryo-toxicity in early life 7
stage development. A test solution is considered toxic when statistically significant, dosedependent increasing percentage of abnormalities occurs. Details of the test are provided in Table 4. Summary of the test conditions for the sea urchin bioassay. Test type Static Test duration 48 h Temperature 16 ± 1C Light intensity dark Photoperiod none Test chamber 6-well microplate No. test organisms/ test chamber 20-50 /mL No. replicate beakers / sample 4 reps/ sample Test chamber aeration None Endpoint Survival Test acceptability criteria (controls) Survival ≥ 70%, Dissolved O2 > 60%
Table 4.
Lux bioassay: inhibition of light from lux-gene modified Escherichia coli Genetically modified E. coli are exposed to a range of concentration of chemicals. The bacterium has been genetically modified to emit light that can be measured in luminescence. In contact with a toxic chemical for the bacteria, the light intensity decreases. The variation of light intensity is used to determine a concentration inhibiting by 50% the light emission (IC50) after 30 min of exposure. The assay was conducted according to Redshaw et al. (2007). Table 5. Summary of the test conditions for the inhibition of light from lux-gene modified Escherichia coli assay Test type Static Test duration 30 min. Temperature 25C Light intensity dark Photoperiod none Test chamber 5mL tube No. test organisms/ test chamber 100µL of bacterial suspension/mL No. replicate beakers / sample 3 reps/ sample Test chamber aeration None Endpoint Light emission Test acceptability criteria (controls) Light ≥ 175 RLU
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Chemical analysis Sampling of the domestic wastewater. Opito Bay Sewage Company Domestic wastewater entering the Optio Bay sewage sump was collected on the last day of the 2013 Easter Holiday weekend. This date was specifically targeted for sampling as it corresponds with the end of a peak period of holiday home occupation in Opito Bay. The septic tank systems within the Ohinau Drive-Thompson Place residential subdivision will have experienced 3-4 days of relatively high volume input and potential overloading. Filtered effluent from these septic tank systems had similarly accumulated for 3-4 days in the central collection/storage sump prior to sampling. This source of domestic septic tank effluent therefore represented a worst case scenario with respect to the level of septic tank treatment it had been subjected to. Samples from the Opito Bay Sewage Company sump were obtained with assistance from Wally Leighton, one of the two designated Directors of the Opito Bay Sewage Company. The manhole to the Sump was removed and samples were obtained from the sump using a weighted bucket device attached to a rope. The bucket was filled twice, the contents used to rinse the bucket and sampling bottles, and discarded. Subsequent samples were used to fill four individual pre-cleaned four litre glass solvent bottles. The bottles of wastewater were transferred into a chilly bin and packed with ice for transport to Plant and Food Research laboratories at Ruakura Research Centre in Hamilton. Upon arrival at Plant and Food Research in Hamilton the sample bottles were transferred into a refrigerator and stored overnight at 4˚C. Wastewater treatment plant influent Wastewater influent samples were obtained from 13 wastewater treatment plants (WWTPs) geographically distributed throughout New Zealand. The WWTPs serviced catchments with populations ranging from 700 to 1,000,000, average daily flows ranging from 900 to 300,000 m3, and the proportion of domestic derived wastewater ranged between 50 to 100% of the total influent flow (Northcott et al. 2013). Influent from the WWTPs was obtained by grab sampling during the peak morning flow event and transferred into pre-cleaned 4 L amber glass Winchester bottles. The samples were transferred into a chilly bin and packed with ice for transport to Plant and Food Research laboratories at Ruakura Research Centre in Hamilton. Upon arrival at Plant and Food Research in Hamilton the sample bottles were transferred into a refrigerator and stored overnight at 4˚C. Kaikoura biosolids A sample of field stored Kaikōura biosolids was obtained as part of the Ministry of Business Innovation and Employment (MBIE) funded Biowaste research programme. This material was originally dredged from the Kaikōura waste water treatment plant oxidation ponds and stored onsite to dewater. Preparation of waste water samples The wastewater samples were adjusted to pH 2.5 by the addition of concentrated sulphuric acid and vacuum filtered through glass fibre cartridges (GFC) filters and filter aid 9
material to remove particulate material. The filtered wastewater samples were extracted by solid-phase extraction (SPE) as described below. The combined GFC filters and filter aid material containing the particulate phase of each sample were frozen for subsequent extraction using accelerated solvent extraction (ASE). Solid phase extraction of filtered waste water samples for bioassay analysis A full description of the methods used to extract and purify dissolved phase samples for bioassay and chemical analyses is provided in Gadd et al (2010). Filtered wastewater was extracted using an Oasis HLB 1 1 g 20 20 mL SPE cartridge. Organic chemicals were eluted from the SPE cartridge with a binary solvent mixture of dichloromethane/methanol and purified by passing through a sequential florosil cartridge (IST, 2 g, 12 mL) into a collection vial. The solvent extract was blown to dryness at a temperature of 30˚C under a gentle stream of nitrogen gas, redissolved in 0.5 mL of dimethyl sulfoxide (DMSO) and transferred to 2 mL amber glass vials. The sample extracts were stored under refrigeration and couriered to Cawthron Institute in Nelson within a polyfoam box packed with freezer pads. Details of the samples are summarised in Table 6. Sample information for Opito Bay septic tank and Kaikōura biosolids bioassay
Table 6. extracts. Sample 1 2 3
Description SPE blank Opito dissolved phase ASE blank
Volume 0.5 mL 1.0 mL 0.5 mL
4 5 DMSO
Opito particulate phase Kaikōura biosolids Solvent for dilution
1.0 mL 2.0 mL 20 mL
Notes SPE, solvent etc 2.8 Litres filtered effluent Extraction cell packing, SPE, solvents etc Particulates from 2.8L filtered sample 5.125 grams DW Kaikōura biosolids DMSO used to prepare bioassay extracts
The filters and particulates were extracted by ASE. The ASE blank (Table 6; sample 3) consisted of an extraction cell with glass fibre thimble packed with hydromatrix and sand. It was extracted with the water/IPA solvent mixtures and conditions as the Opito Bay particulate phase and Kaikōura biosolids (Table 6; samples 4 and 5) and is the corresponding blank for these two samples.
Solid phase extraction of filtered wastewater samples for chemical analysis One to two litres of acidified and filtered wastewater was spiked with a solution of carbon13 labelled surrogate standards and extracted using an Oasis HLB 1 g 20 mL SPE cartridge. The SPE cartridges were dried under full vacuum and the organic chemicals were eluted from the SPE cartridge with a binary solvent mixture of dichloromethane/methanol and purified by passing through a sequential florosil cartridge (IST, 2 g, 12 mL) into a collection vial. The solvent extract was concentrated and exchanged into dichloromethane and further purified using gel permeation chromatography. The purified sample extract was split into two, one half for the analysis of non-polar organic compounds, and the other half for the analysis of polar organic compounds. The non-polar fraction of sample was blown to dryness at a temperature of 30˚C under a gentle stream of nitrogen gas and re-dissolved in isooctane. A solution of isotopic labelled 10
internal standards was added to the non-polar sample fraction, the extracts were transferred into vials, capped and sealed and stored under refrigeration for analysis. The remaining half of the purified sample extract destined for the analysis of polar organic compounds was blown to dryness at a temperature of 30˚C under a gentle stream of nitrogen gas. A mixture of isotopic labelled internal standards was added to each extract and the steroid hormones and other polar chemical residues were derivatised to their respective trimethylsilyl ethers. The derivatised extracts were dissolved in isooctane, transferred into vials, capped and sealed and stored under refrigeration for analysis. Accelerated solvent extraction of filtered particulates and biosolids The samples of biosolids and filtered particulates were extracted according to the method of Burkhardt using a Dionex ASE 200 accelerated solvent extraction system and 22 mL stainless steel extraction cells (Burkhardt et al. 2005). A glass fibre extraction thimble placed into the cell before it was loaded with the combined glass fibre filter and filter aid material, or field moist biosolids. Void space remaining in the ASE cell was filled with precleaned Ottawa and the cell sealed with the screw cap. The samples were sequentially extracted using a two stage procedure. The sample cells were first extracted at 120 ˚C with a binary mix of water/IPA (50:50, v/v) to minimise thermal degradation of labile compounds. The same cells were then extracted at 180˚C with a second binary mix of water/IPA (20:80, v/v). The cells were sequentially extracted for 10 min two times with each of the extraction solutions at a pressure of 2000 psi. The extracts obtained for each extraction solution were collected in separate 60 mL glass vials. Each sample was extracted in duplicate to provide one set of sample extracts for bioassay analysis and another for chemical analysis. Samples intended for chemical analysis were spiked with a solution of isotopic labelled surrogate standards in the ASE cell prior to being sealed with the screw cap. Extraction of accelerated solvent extraction solutions Organic chemicals present in the IPA/water sample extracts obtained by ASE were concentrated by SPE. The IPA/water extracts obtained for each sample were combined and diluted with phosphate buffer to facilitate the extraction of both hydrophobic and polar organic compounds (Burkhardt et al. 2005). The diluted phosphate buffer solution was extracted using an Oasis HLB 1 1 g 20 20 mL SPE cartridge. The SPE cartridges were dried under full vacuum and the organic chemicals were eluted from the SPE cartridge with a binary solvent mixture of dichloromethane/methanol (50:50/95:5) and purified by passing through a sequential florosil cartridge (IST, 2 g, 12 mL) into a collection vial. The set of sample extracts destined for bioassay analysis were blown to dryness at a temperature of 30˚C under a gentle stream of nitrogen gas, redissolved in 0.5 mL of DMSO and transferred to 2 mL amber glass vials. The sample extracts were stored under refrigeration and couriered to Cawthron Institute in Nelson within a polyfoam box packed with freezer pads. Solvent extracts destined for chemical analysis required further purification. This set of solvent extracts was concentrated and exchanged into dichloromethane and further purified using gel permeation chromatography. The purified sample extract was split into two, one half for the analysis of non-polar organic compounds, and the other half for the analysis of polar organic compounds. The non-polar fraction of sample was blown to dryness at a temperature of 30˚C under a gentle stream of nitrogen gas and re-dissolved in isooctane. A solution of isotopically labelled internal standards was added to the non11
polar sample fraction, the extracts were transferred into vials, capped and sealed and stored under refrigeration for analysis. The remaining half of the purified sample extract destined for the analysis of polar organic compounds was blown to dryness at a temperature of 30˚C under a gentle stream of nitrogen gas. A mixture of isotopically labelled internal standards was added to each extract and the steroid hormones and other polar chemical residues were derivatised to their respective trimethylsilyl ethers (Labadie and Budzinski, 2005). The derivatised extracts were dissolved in isooctane, transferred into vials, capped and sealed and stored under refrigeration for analysis. Instrumental analysis The target compounds were analysed by gas chromatography–mass spectrometry (GCMS) using an Agilent 6890 gas chromatograph fitted with an Agilent split/splitless injector, PAL autosampler and an Agilent 5975 quadrupole mass selective detector (MSD). Individual compounds were separated using a HP-5MS capillary column (length 30 m, film thickness 0.25 µm, inner diameter 0.25 mm, Agilent) with an initial oven temperature of 90 °C for 1.5 min, then increasing at 20 °C/ min to 130 °C, followed by 4 °C/ min to 232°C and 50°C/ min to 320°C with a hold for 7 min (total run time 37.7 min). Helium was used as carrier gas at a flow rate of 1.0 ml/min. The sample was injected (1 µL) into a split/splitless injector held at 280°C. Transfer of volatile analytes onto the column was enhanced using pressure pulsed injection at 30 psi for 1.10 min with a splitless time of 1 minute and spit flow rate of 50 mL/min. Following this pressure pulse, the column flow was held at 1.0 mL/min by electronic pressure control. The GC–MS interface was held at 280°C and the ion source and quadrupole temperatures were set at 230 and 150°C, respectively. Electron Impact Spectra (EIS) were obtained at 70 eV. The MSD was calibrated against PTFBA using the autotune function. The resulting electron multiplier voltage (EMV) was increased by 300 EMV for increased sensitivity. The solvent delay time was 6.5 minutes. Mass spectral data was acquired using the synchronous scan/single ion monitoring (SIM) mode. Data analysis was undertaken using the ChemStation software using data acquired in the SIM mode. Quantitation of target compounds and surrogate standards in final sample extracts was carried out using internal standard quantitation, based upon the relative response factors determined against corresponding internal standards using eight-point linear calibration curves prepared over the concentration range of 5-1000 ng/mL. Using SIM data the instrument detection limit for target compounds was 5-10 ng/mL. The calculated method detection limit (MDL) for target compounds and surrogate standards ranged from 0.5 to 20 ng/L (parts per trillion) for wastewater samples and 0.05 to 10ng/g dry weight (parts per billion) for biosolids and particulate phases of wastewater samples.
Results Toxicity of the selected chemicals and waste samples using the algal test
The selected chemicals were tested using the freshwater green micro-algae P subcapitata assay according to the protocol described above. Some of the chemicals including 12
gemfibrozil could not be tested as they were not soluble. The results are summarised in Table 7.
Table 7. Results from the toxicity testing of household chemicals using the freshwater micro-algae P subcapitata (with the 95% confidence intervals (CI)). Chemical IC50 (mg/L) (95% CI) Benzophenone 12.8 (11.3 – 14.4) Bisphenol A 6.9 (5.8 – 7.7) Chloroxylenol 0.6 (0.4 – 0.8) DEET 106.0 (94.5 – 117.4) Diclofenac 47.3 (40.6 – 53.9) Octyl-methoxycinnamate 9.6 (5.1 – 14.1) 2-Phenoxyethanol 407.4 (369.2 – 445.6) 2-Phenylphenol 53.7 (37.7 – 76.4) Triclosan 9.1 (3.8 – 17.6) The sewage treatment plant extracts were diluted in DMSO. For the algal test, the maximum concentration in the test solution was 0.4% corresponding to the maximum tested concentration of the extract. Nineteen concentrations (in % of extract in the test solution) were tested: C0: control, C1: 5.65 ×10-06, C2: 1.02×10-05, C3: 1.83×10-05, C4: 3.3×10-05, C5: 5.93×10-05, C6: 1.1×10-04, C7: 1.9×10-04, C8: 3.5×10-04, C9: 6.2×10-04, C10: 1.12×10-03, C11: 2×10-03 , C12: 3.6×10-03, C13: 6.5×10-03, C14: 1.2×10-02, C15: 2.1×10-02, C16: 3.8×10-02, C17: 6.9×10-02, C18: 0.123, C19: 0.222, C20: 0.4. The results from the testing of the wastewater extracts are summarised in Table 8. Both SPE and ASE blanks showed no toxicity (data not shown). Table 8. Results from the toxicity testing of sewage extracts using the freshwater micro-algae P subcapitata (with the 95% confidence intervals (CI)). Extract IC50* (%) 95% CI Opito Bay dissolved phase 0.184 0.054 – 0.314 Opito Bay particulate phase 0.224 0.147 – 0.291 Kaikōura biosolids 0.270 0.142 – 0.397 (*using a three parameters log-logistic regression on transformed data)
The results from the individual dilutions of the waste extract tested are provided in Figure 2, Figure 3 and Figure 4.
13
Growth (number of cell. 10^3) 600000 *
Opito dissolved phase
*
500000
*
400000 300000
200000
* 100000 0
C0
C1
C2
C3
C4
C5
C6
C7
C8
C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 Concentrations
Figure 2. Toxicity results of the Opito Bay septic tank effluent sample dissolved fraction extract serial dilutions reported as means and standard deviations of the algal growth. * Indicates a statistically difference from the control (p < 0.05). Opito particulate phase
Growth (number of cell. 600000 10^3) 500000 400000 300000 200000 100000 0 C0
C1
C2
C3
C4
C5
C6
C7
C8
C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 Concentrations
Figure 3. Toxicity results of the Opito Bay septic tank effluent sample particulate phase extract serial dilutions reported as means and standard deviations of the algal growth.
14
Kaikoura biosolid
Growth (number of cell. 10^3)
600000 500000
*
*
*
* *
*
* *
400000
300000
*
200000 100000 0 C0
C1
C2
C3
C4
C5
C6
C7
C8
C9 C10 C11 C12 C13 C14 C15 C16 C17 C18 C19 C20 Concentrations
Figure 4. Toxicity results of the serial dilution samples of the Kaikōura biosolids extract reported as means and standard deviations of the algal growth. * Indicates a statistically difference from the control (p < 0.05).
The lowest concentrations of the Opito Bay septic tank dissolved phase and Kaikōura biosolids extracts significantly stimulated (P290 nm, but may have some susceptibility to direct photolysis. If released to soil, BPA may have high to slight mobility based upon a Koc range of 115 to 3886. Most of the measured Koc values suggest that BPA may have moderate to low mobility in soil. The pKa of BPA is 9.6, indicating that this compound will exist partially in anion form in the environment and anions generally 24
do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. The partial dissociation of BPA in environmental media may be one reason for the wide range of observed soil adsorption. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 4.0×10-11 atm-m3/mol at 25C. Bisphenol A is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Although BPA has been found to be non-biodegradable in various studies and screening tests, other studies have found BPA to be readily biodegradable or inherently biodegradable, especially after short lag periods of acclimation. If released into water, BPA is expected to adsorb to suspended solids and sediment based upon the Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. A BCF range of 5.1 to 73.4 suggests bioconcentration in aquatic organisms is low to moderate. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Sensitized photooxidation may be an important as a fate process for BPA in sunlit natural water. Occupational exposure to BPA may occur through inhalation and dermal contact with this compound at workplaces where BPA is produced or used. Monitoring data indicate that the general population may be exposed to BPA via inhalation of ambient air, contact with house dust, ingestion of food and drinking water. Use data indicate direct exposure is likely via interaction with consumer products containing this compound as it is widely used in commodity packaging such as resusable containers and these residues may migrate into foods.
Chloroxylenol OH
H3C
CH3 Cl
Cas number
88-04-0
Boiling point
160C
Relative density Vapour pressure
0.996 at 20C 0.1 mm Hg at 20˚C
5.1×10-7 atm-m3/mol at 25C Solubility in water > 1g/L Partition coefficient (log Kow) 2.02 Adsorption coefficient (Koc) 1400 BCF 66 Henry's law constant
Chloroxylenol's production and use as an antibacterial, germicide, antiseptic and in mildew prevention may result in its release to the environment through various waste streams. If released to air, a vapour pressure of 0.1 mm Hg at 20˚C indicates chloroxylenol will exist solely as a vapour in the atmosphere. Vapour-phase chloroxylenol will be 25
degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 5.8 hours. Chloroxylenol does not absorb at wavelengths >290 nm and has been reported to be stable to sunlight for up to 24 hours. If released to soil, chloroxylenol is expected to have low mobility based upon an estimated Koc of 1,400. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 5.1×10-7 atm-m3/mol at 25C. Chloroxylenol is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 10 hours and 9 days, respectively. Degradation of chloroxylenol appears to be slower than other phenol derivatives. Studies in sewage showed 8095% of the original compound remaining after 2 days and 60-70% remaining after 7 days. This is consistent with other studies that showed less than 40% degradation in activated sludge over 7 days. If released into water, chloroxylenol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. An estimated BCF of 66 suggests the potential for bioconcentration in aquatic organisms is moderate. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Occupational exposure to chloroxylenol may occur through inhalation and dermal contact with this compound at workplaces where chloroxylenol is produced or used. The most likely route of exposure to the general population is through dermal contact when using soaps or cleaning products that contain chloroxylenol as an antibacterial. A smaller population may be exposed to chloroxylenol when taking medications that contain chloroxylenol as an active ingredient
DEET CH3 N CH3 O H3C
Cas number Appearance
134-62-3 liquid
Boiling point
160C at 19 mmHg
Relative density Vapour pressure
0.996 5.6×10-3 mm Hg at 20C
Henry's law constant Partition coefficient (log Kow) Adsorption coefficient (Koc) BCF
2.1×10-8 atm-m3/mol 2.02 300 0.8 – 2.4
26
EET's production and use as insect and acarid repellent is expected to result in its direct release to the environment. If released to air, a vapor pressure of 5.6×10-3 mm Hg at 20C indicates DEET will exist solely as a vapour in the ambient atmosphere. Vapour-phase DEET will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 15 hrs. If released to soil, DEET is expected to have moderate mobility based upon an estimated Koc of 300. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2.1×10-8 atm-m3/mol. Based on limited data, this compound should not readily biodegrade under either aerobic or anaerobic conditions in neither soil nor water. If released into water, DEET is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. BCF values of 0.8-2.4 suggest bioconcentration in aquatic organisms is low. DEET is stable to hydrolysis at environmental pHs of 5, 7, and 9. Occupational exposure to DEET may occur through inhalation and dermal contact with this compound at workplaces where DEET is produced or has been and continues to be used. The general population may be exposed to DEET via dermal contact with consumer products (insect repellent) containing DEET
Diclofenac O Cl
OH NH
Cl
Cas number Appearance Melting point
15307-79-6 Crystals from ether-petroleum ether 156-158C
Vapour pressure
6.1×10-8 mm Hg at 25C
Henry's law constant Solubility in water Dissociation constant (pKa) Partition coefficient (log Kow) Adsorption coefficient (Koc) BCF
4.73×10-12 atm-m3/mol at 25C 2.37 mg/L at 25C 4.15 4.51 245 3
Diclofenac's production and use as an anti-inflammatory may result in its release to the environment through various waste streams. If released to air, an estimated vapour pressure of 6.1×10-8 mm Hg at 25 ˚C indicates diclofenac will exist in both the vapor and particulate phases in the ambient atmosphere. Vapour-phase diclofenac will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this 27
reaction in air is estimated to be 0.8 hrs. Particulate-phase diclofenac will be removed from the atmosphere by wet and dry deposition. If released to soil, diclofenac is expected to have moderate mobility based upon an estimated Koc of 245. The pKa of diclofenac is 4.15, indicating that this compound will exist almost entirely in the dissociated form in the environment and anions generally do not adsorb more strongly to organic carbon and clay than their neutral counterparts nor do anions volatilize. Volatilization from moist soil is not expected because the compound exists as an anion and anions do not volatilize. Diclofenac is not expected to volatilize from dry soil surfaces based upon the estimated vapor pressure. Biodegradation in the environment is not an important fate process based upon little or no biodegradation using a freshwater inoculum. If released into water, diclofenac is expected to adsorb to suspended solids and sediment based upon the estimated Koc. A pKa of 4.15 indicates diclofenac will exist almost entirely in the ionized form at pH values of 5 to 9 and therefore volatilization from water surfaces is not expected to be an important fate process. An estimated BCF of 3 suggests the potential for bioconcentration in aquatic organisms is low. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Direct photolysis is the predominant removal process in freshwater, exhibiting a half-life of 8 days. Occupational exposure to diclofenac may occur through dermal contact with this compound at workplaces where diclofenac is produced or used. Monitoring data indicate that the general population may be exposed to diclofenac via ingestion of drinking water, dermal contact with this compound, and pharmaceutical use of consumer products containing diclofenac.
4-Methylbenzylidene camphor CH3 CH3 O
CH3
CH3
Cas number Use class Appearance Melting point Solubility in water
36861-47-9 UV-B absorber White crystalline powder 66-69C insoluble
Octyl methoxycinnamate O
O
O
H3C CH3
Cas number
5466-77-3 28
CH3
Name (IUPAC)
Octinaxate
Boiling point
185-195C at 1 mbar
Vapour pressure
1.4×10-5 mm Hg at 25C (est)
Henry's law constant
1.8×10-6 atm-m3/mol at 25C (est)
Solubility in water 0.16 mg/L at 25C (est) Partition coefficient (log Kow) 5.8 (est) Adsorption coefficient (Koc) 12000 pH7: 36 y Hydrolytic stability (DT50) pH8: 3.6 y
Octinoxate's production and use as an ingredient in sunscreen may result in its release to the environment through various waste streams. If released to air, an estimated vapour pressure of 1.4×10-5 mm Hg at 25C 25˚C indicates octinoxate will exist in both the vapor and particulate phases in the atmosphere. Vapour-phase octinoxate will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 7.5 hours. The half-life for the reaction of octinoxate with ozone is 1.1 days. Particulate-phase octinoxate will be removed from the atmosphere by wet or dry deposition. Octinoxate absorbs light at wavelength 310 nm and therefore may be susceptible to direct photolysis by sunlight. If released to soil, octinoxate is expected to have no mobility based upon an estimated Koc of 12000. Volatilization from moist soil surfaces is expected to be an important fate process based upon an estimated Henry's Law constant of 1.8×10-6 atm-m3/mol at 25C. However, adsorption to soil is expected to attenuate volatilization. Octinoxate is not expected to volatilize from dry soil surfaces based upon its vapour pressure. Biodegradation data were not available for octinoxate. If released into water, octyl methoxycinnamate is expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is expected to be an important fate process based upon this compound's estimated Henry's Law constant. Estimated volatilization half-lives for a model river and model lake are 5.0 and 60 days, respectively. However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. The volatilization half-life from a model pond is about 1 year when adsorption is considered. An estimated BCF of 5900 suggests the potential for bioconcentration in aquatic organisms is very high. Hydrolysis half-lives estimated for octinoxate are 36 and 3.6 years at pH values of 7 and 8, respectively. Occupational exposure to octyl methoxycinnamate may occur through inhalation or dermal contact with this compound at workplaces where octinoxate is produced or used. The general population will be exposed to octinoxate via application of sunscreen containing this substance.
29
2-Phenoxyethanol O OH
Cas number 122-99-6 Name (IUPAC) Ethylene glycol monophenyl ether Use class solvent, fixative, bactericidal agent Appearance oily liquid, colourless Melting point 11 - 13C Boiling point 244 - 246C Relative density 1.107 at 20C Vapour pressure 0.933 Pa at 25C Henry's law constant 4.96 ×10-3 Pa.m3/mole Solubility in organic solvents 27 g/L (at 20C) Partition coefficient (log Kow) 1.13 Adsorption coefficient (Koc) 15 BCF N/A 2-Phenoxyethanol's production and use as a solvent for cellulose acetate and dyes, in inks and resins, as a perfume fixative, as a bactericidal agent, in organic synthesis of plasticizers, germicides and pharmaceuticals, and in insect repellents may result in its release to the environment through various waste streams. If released to air, a vapour pressure of 0.933 Pa at 25C indicates 2phenoxyethanol will exist solely as a vapour in the atmosphere. Vapour-phase 2phenoxyethanol will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 11.8 hours. Monitoring data have shown that 2-phenoxyethanol can be removed from the atmosphere via precipitation including snow. 2Phenoxyethanol does not absorb at wavelengths >290 nm, and therefore is not expected to be susceptible to direct photolysis by sunlight. If released to soil, 2-phenoxyethanol is expected to have very high mobility based upon an estimated Koc of 15. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 4.96 ×10-3 Pa.m3/mole. If released into water, 2-phenoxyethanol is not expected to adsorb to suspended solids and sediment based upon the estimated Koc. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. Theoretical BODs of 2% (5-day), 71% (10-day), 50% (20-day) and 80% (20-day) have been reported for 2phenoxyethanol indicating it will be largely removed during biological waste treatment. 2-Phenoxyethanol is not expected to undergo hydrolysis in the environment due to the lack of functional groups that hydrolyze under environmental conditions. Occupational exposure to the 2-phenoxyethanol occurs through inhalation of vapor and dermal contact. Its use as solvent for inks, resins and cellulose acetate and its use as a perfume fixative could expose the general population through dermal contact and inhalation of vapour.
30
2-Phenylphenol OH
Cas number Vapour pressure
90-43-7 0.002 mm Hg at 25˚C
Henry's law constant
0.002 mm Hg at 25˚C.
Solubility in water Solubility in organic solvents (at 20C) Partition coefficient (log Kow) Adsorption coefficient (Koc) BCF
0.76 g/L acetone: 479 g/L 3.12 6700 51
o-Phenylphenol's production and use in rubber chemicals, in food packaging, as an intermediate for dyes, and as a food preservative may result in its release to the environment through various waste streams; its use as a pesticide and household disinfectant and for sapstain control in freshly cut lumber is expected to result in its direct release to the environment. o-Phenylphenol may be formed in the environment as a microbial metabolite of biphenyl. If released to air, a vapour pressure of 0.002 mm Hg at 25˚C indicates ophenylphenol will exist solely as a vapour in the ambient atmosphere. Vaporphase o-phenylphenol will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 1.4 hours. o-Phenylphenol absorbs light in the environmental UV spectrum and may undergo direct photolysis. If released to soil, o-phenylphenol is expected to be immobile based upon an estimated Koc of 6,700. Volatilization from moist soil surfaces may be an important fate process based upon a Henry's Law constant 0.002 mm Hg at 25˚C. oPhenylphenol is not expected to volatilize from dry soil surfaces based upon its vapor pressure. Utilizing the Japanese MITI test, o-phenylphenol reached 47-86% of its theoretical BOD in 2 weeks indicating that biodegradation may be an important environmental fate process. If released into water, o-phenylphenol is expected to adsorb to sediment and suspended solids in water based upon the estimated Koc. Biodegradation in water is expected based on a 50% reduction of o-phenylphenol concentration within 1 week in river water. Volatilization from water surfaces may occur based upon this compound's Henry's Law constant. However, volatilization from water surfaces is expected to be attenuated by adsorption to suspended solids and sediment in the water column. An estimated BCF of 51 suggests the potential for bioconcentration in aquatic organisms is moderate. Hydrolysis is not expected to occur due to the lack of hydrolyzable functional groups. Occupational exposure to o-phenylphenol may occur through inhalation and dermal contact with this compound at workplaces where o-phenylphenol is produced or used. Field workers or sorters and packers in the citrus and pear industry are at the greatest risk of exposure to o-phenylphenol. The general population may be exposed to o-phenylphenol via inhalation of indoor and outdoor air, ingestion of food and drinking water, and dermal contact with this compound 31
and household disinfectant products, such as "Lysol", containing o-phenylphenol. o-Phenylphenol has been designated by the EPA as an active ingredient and food contact sanitizer due to its use as a post-harvest antimicrobial agent and preservative on fruit and vegetables.
Triclosan Cl
OH O
Cl
Cl
Cas number Appearance Melting point
3380-34-5 White to off-white crystalline powder 54 – 57.3C
Boiling point
280 to 290C
Vapour pressure
4.6×10-6 mm Hg at 25C
Henry's law constant Solubility in water Dissociation constant (pKa) Partition coefficient (log Kow) Adsorption coefficient (Koc) Photostability (DT50) BCF
2.1×10-8 atm-m3/mol at 25C 10 mg/L at 20C 7.9 4.76 2400 to 15,892 17 d 2.7 - 90
Triclosan's production may result in its release to the environment through various waste streams; its use as a bacteriostat and preservative for cosmetic and detergent preparations will result in its direct release to the environment. Triclosan has been in use for over 30 years in a vast array of consumer products including preservative and disinfectant in footwear (hosiery and insoles), hospital handsoap, and acne creams, and it has been incorporated into plastic products ranging from children's toys to kitchen utensils. If released to air, an estimated vapour pressure of 4.6×10-6 mm Hg at 25C indicates triclosan will exist in both the vapour and particulate phases in the atmosphere. Vapour-phase triclosan will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be 24 hours. Particulate-phase triclosan will be removed from the atmosphere by wet or dry deposition. If released to soil, triclosan is expected to have low to no mobility based upon Koc values of 2400 to 15,892. The pKa of triclosan is 7.9, indicating that this compound will exist partially in anion form in the environment and anions generally do not adsorb more strongly to soils containing organic carbon and clay than their neutral counterparts. Volatilization from moist soil surfaces is not expected to be an important fate process based upon an estimated Henry's Law constant of 2.1×10-8 atm-m3/mol at 25C and the pKa. Utilizing the Japanese MITI test, 0% of the theoretical BOD was reached in four weeks indicating that biodegradation is not an 32
important environmental fate process in soil. Triclosan had a photodegradation half-life of 17 days on dry loamy soil. If released into water, triclosan is expected to adsorb to suspended solids and sediment based upon the Koc values. Triclosan was shown to biodegrade in grey water under aerobic, anaerobic and anaerobic/aerobic conditions. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant and pKa. Measured BCFs in orange-red killifish of 2.7 to 90 suggest bioconcentration in aquatic organisms is low to moderate. Hydrolysis is not expected to be an important environmental fate process since this compound lacks functional groups that hydrolyze under environmental conditions. Photolytic degradation of triclosan was measured in fresh and sea water with half-lives of 8 and 4 days, respectively, with a degradation product of 2,8-dichlorodibenzo-p-dioxin. Occupational exposure to triclosan may occur through dermal contact with this compound at workplaces where triclosan is produced or used. Monitoring and use data indicate that the general population may be exposed to triclosan via dermal contact with and ingestion of consumer products containing triclosan.
33
Appendix C Ranking details Chemical Benzophenone Bisphenol A Chloroxylenol DEET Diclofenac Octylmethoxycinnamate 2-Phenoxyethanol 2-Phenylphenol Triclosan
Log P 3.18 3.31 2.8 2.02 4.51 5.8
Koc 430 - 517 115 - 3886 1400 300 245 12000
BCF 3.4 - 12 5.1 - 73.4 66 0.8 - 204 3 5900
IC50 (mg/L) 12.8 (11.3 – 14.4) 6.9 (5.8 – 7.7) 0.6 (0.4 – 0.8) 106.0 (94.5 – 117.4) 47.3 (40.6 – 53.9) 9.6 (5.1 – 14.1)
1.13 3.12 4.8
15 6700 2400 - 15892
N/A 51 2.7 - 90
407.4 (369.2 – 445.6) 53.7 (37.7 – 76.4) 9.1 (3.8 – 17.6)
The data have a score attributed depending on their value. The score is then weighed (log P×1, Koc×1, BCF×2, IC50×4) to reflect the importance of each parameters. The ranking is the sum of the scores obtained. Category scoring Chemical
Ranking Log P Koc BCF
Benzophenone Bisphenol A Chloroxylenol DEET Diclofenac Octyl-methoxycinnamate 2-Phenoxyethanol 2-Phenylphenol Triclosan
3 4 3 3 5 6 2 3 5
4 4 4 3 3 5 2 5 5
IC50
6 6 6 8 4 10 4* 6 6
8 12 16 4 8 12 4 8 12
21 26 29 18 20 33 12 22 28
*no data available, intermediate value applied (log) P: Partition coefficient, is a measure of how a chemical will distribute between two immiscible solvents: water (a polar solvent) and octanol (a relatively non-polar solvent). Koc: Adsorption coefficient is a measure of how strongly a chemical adheres to soil in preference to remaining dissolved in water. BCF: bioconcentration factor, describes the accumulation of toxicants (ie. from the water to the organism), for aquatic animals. IC50: It measures the toxicity of a chemical toward a selected organism on a defined endpoint; the concentration inhibiting the growth of the population of the freshwater algae by 50% .
Scoring used: Log Kow < 0.8 0.8 - < 2 2 – < 3.2 3.2 – < 4.5 4.5 – < 5.5
Score
BCF
