New technology for mould inspection and remediation

New technology for mould inspection and remediation Kevin White, Cedric Cheong, Heike Neumeister-Kemp, Wayne Midson

Ausclean WA 19-20 March 2013 Esplanade Hotel, Fremantle

Content Rapid advances in technology, processes and knowledge in the field of mould inspection and remediation have required the industry to embrace new thought processes and to think beyond the scope in order to better service customers and clients. Not all things new will result in a better outcome. This presentation highlights some of the more recent gadgets, equipment and processes within the last couple of years that have gained popularity. A brief synopsis on the pros and cons of each technology will be given.

Background info - Inspection Trained Visual inspection

Mould Grading • Targeted investigations

Targeted sampling & monitoring

• Scientific data • Comprehensive analyses

Informed decisions

Further destructive and forensic investigation •Moisture testing •Borescope • Bulk sampling • Hidden mould • Roof cavities • Sub floor inspection • Health surveillance

Targeted Scope of Works • • • •

Mould contaminant removal Mould remediation Address source of problem Property reinstatement

Clearance Testing for re-habitation

Background info - Remediation Physical Removal (Main action)

Targeted SOW

Fix the Source of Moisture • Structural Drying

• • • •

Mould contaminant removal HEPA vacuuming (horse hair brush) Microfibre cloth (Damp wiping) Vinegar and/or Alcohol solution

Other Adjunct Techniques Containment & PPE

• • • •

Hydrogen Peroxide (H2O2) Ozone (O3) Hydroxyls (OH-) Encapsulants, Sprays & Fogging

Clearance Testing

Visual Inspection – LED Torch

Visual Inspection – LED Torch LED torch with HD Video Camera • Recording format: AVI • Frame rate: 30fps • 1280 * 720 DPI • Recording time: up to 4 hours • Video compression: MJPEG • Rechargeable battery included

Don’t drop it on hard surfaces as optics seem fragile

LED video torch • Roof space

Protimeter

Versatility

The Protimeter … Just like a roll of duct tape to MacGyver

Hygrometer Selection and use • • • • •

Temperature Relative humidity Dew point Specific humidity (ABS) Correct outdoor / reference measurement

Condensator

Condensator

• •

Measure surface temperature If surface temperature falls below dew point for given parcel of air condensation will form

Moisture Meter Search mode • • • •

Remove hygrostick Not suitable for textured finishes Penetration to ~ 15 mm Will penetrate through low density coverings such as carpet

Moisture Mapping Note the significant differences between measurements taken only a few centimetres apart. Such large differences over very short distances illustrate why knowing the exact location of the measurement is important for understanding its true importance.

The previous example illustrates that mould growth rates can be highly variable over short distances.

Moisture Mapping

Remember wood moisture equivalent. Gyprock true moisture content leaving the factory is about 0.4% moisture and can’t hold more than about 2% even when soaking wet.

It is usually helpful to document the exact location and full context of moisture values

ABS Humidity all Bedrooms

1.4

abS Humidity ration - Indoor Vs Room

1.3 Bedroom 1 Bedroom 3 Bedroom 4 Bedroom 2

1.2

1.1

1

0.9

0.8

0.7

0.6 22/05/2012

26/06/2012

26/06/2012

29/06/2012

23/07/2012

Infra red thermography A great adjunct technology

Exterior inspection Upstairs exterior shower showing cold spots

Planter boxes showing cold spot and water logging against structural house wall

Sampling – risk assessment GROWTH MEDIA Agar plates may be formulated as either permissive i.e. allows the growth of whatever organisms are present, selective, i.e. allows growth a particular subset or may be indicative i.e. organisms are not selected on the basis of growth, but are instead distinguished by a color change in some colonies e.g. fecal coliforms

Sampling – risk assessment BACTERIA GROWTH MEDIA Blood agar typically used for bacteria. • Brain-Heart Infused agar is specified in Standard Methods for the examination of water and wastewater and in tests for the verification of fecal streptococci. • Chocolate agar used to grow fastidious respiratory bacteria, such as Haemophilus influenzae. • Thayer-Martin agar is a chocolate agar designed to isolate Neisseria gonorrhoeae.

Sampling – risk assessment MOULD GROWTH MEDIA Malt Extract is typically used for mould identification and numeration. International references typically describe the colour and other characteristics of fungi on this type of media, on different media those characteristic may be vary significantly.

• Potato Dextrose Agar (PDA) is recommended for foods, dairy products and cosmetics testing. • Nutrient Agar is specified in many standard methods procedures for the examination of food, dairy products, water.

Rapid Sampling bioluminescence-based ATP assays Adenosine triphosphate (ATP) – is a bio-marker and the principle energy carrier for all living organisms. A number of products are now on the market to quickly quantify the amount of ATP present on a surface which can then be correlated to the amount of bacteria or mould present on a surface. • Pros ... • • • •

Relatively cheap Quick turnaround (5 – 30 mins) Gives a number ... Everybody like a “number” May be a good post remediation validation tool

bioluminescence-based ATP assays • Cons ... • Concerns about suitability of application for risk assessment. • Subject to large potential for error. • Measurements can provide an indication of the quality of cleaning but should not be interpreted as a direct indicator of microbial surface contamination. • ATP levels can be influenced by environmental stresses on organisms activating survival strategies. Stressed – up to 250%, unstressed 50%. • Swabbing is conducted to measure surface ATP – efficiency dependent on material’s characteristics. • The greater the mechanical force expended during swab sampling the greater the pickup efficiency from wet surfaces. Lower recoveries obtained from dry surfaces. • Manner in which organisms are deposited at the surface will also influence efficiency with which they can be removed.

bioluminescence-based ATP assays • Cons ... • Pickup efficiency also affected by concentration of organisms present at surface – efficiency decreasing with increasing bacterial concentration. • Cleaning agents and sanitisers and the very act of cleaning and disinfecting surfaces will result in surfaces becoming contaminated with traces of agents used for cleaning. These residues will be picked up by the swabs and will be released into the reagent tubes which form part of all rapid ATP test kits. These agents can have a confounding effect on ATP measurements as conducted using luciferin-luciferase based systems. Acidic foam cleanser – false positives. Alkaline foam cleansers – false negatives.

Respiratory Protective Equipment • All persons engaged in inspection or remediation of mould should wear respiratory protective equipment (RPE) conforming with the requirements of – AS/NZS 1716 : 2012 Respiratory Protective Devices

• The selection, use and maintenance of respirators should be in accordance with – AS/NZS 1715 : 2009 Selection, Use and Maintenance of Respiratory Protective Devices

Duty of Care Respiratory Protection Equipment must be “fit for purpose” Fit testing / checking. The importance of correct facial fit. The correct method of using respirators. Limitations of respirators. The procedures for regular cleaning, inspection and maintenance of respirators before use. Employer required to keep record of all respirator issues, fit tests, maintenance and repair, and the RPE instruction and training provided to their workers.

AS/NZ 1715:2009

Duty of Care RPE limitations

Communication

Mould Remediation • Main aim of mould remediation / cleaning is the REMOVAL of spores – Physical agitation & removal

HEPA vacuuming (70-60%) Damp wiping micro-fibre cloth (20-15%) Vinegar / Alcohol (5%) Sanitisation (5%)

Background info - Remediation • HEPA vacuuming / soft horse hair brush – High Efficiency Particulate Arrestor – Removes 99.97% of all particulates > 0.3 mm  – Physical agitation

• Micro-fibre technology – Large surface area – Fibres getting into small crevices & cracks

Why Use Micro-fibre Cloths? • These strands create a surface area covered with millions of spaces between the fibres to trap moisture, dirt and debris, and also reach into microscopic cracks and crevices that would be otherwise missed when using a conventional cloth.

Media blasting Over the last few years media blasting in the USA for architectural restoration - baking soda, dry ice, and other blast media – has became a mainstream tool for mould remediation, fire restoration, and other large cleaning and reconstruction jobs. When evaluating these technologies it is important to understand some significant differences in building construction methods in the USA versus Australia. In the States there is a heavy reliance on timber products for engineering purposes and cladding.

Media blasting In the States conventional cleaning methods require mould remediators to manually sand, scrape or wire brush the mould from the contaminated surface. This can be a slow, tedious and generally unpleasant process to endure. It is also virtually impossible to completely remove the mould through these methods; contractors are often limited by tight angles and close and confined spaces, which can lead to difficulties when trying to sand mould off wood. Consequently the high labour costs in the States associated with conventional remediation have been a key driver in the promotion of media blasting.

Dry Ice blasting Dry ice blasting works like sandblasting or high-pressure water blasting, it is a process in which a blasting gun fires dry ice particles (rice-sized) at supersonic speed to impact and clean a surface. The particles are accelerated by compressed air, just as with other blasting systems. Upon impact the dry ice sublimates; goes from a solid to a gas without passing through a liquid phase, generating a volume expansion of 400 to 800 times and lifting the mould off the wood. However these high velocities can also leave the timber surfaces dimpled and typically removes about 1 mm of the wood surface being cleaned.

Dry Ice blasting

Soda blasting Soda blasting is a very effective and popular method of media blasting for mold remediation, particularly because it does not cause much damage to wood. Soda blasting is softer than the other blasting media; however, it produces a significant amount of dust and leaves a good deal of debris from the blast media that has to be cleaned.

Soda blasting

Media blasting Both methods require strong containment. Both methods require clean-up of waste; more so with Soda blasting. The level of aggressive blasting can be altered with Soda. Soda blasting costs are cheaper but arguably more waste to clean up. Baking soda and dry ice are blast media that have specific problems associated with their use. Heat, humidity, and compressed air laden with water and contaminants all have a negative impact on the way these exotic media behave.

Media blasting Baking soda tends to get lumpy when wet, and small quantities are hard to meter into the blast stream consistently. Dry ice begins deteriorating rapidly from the time it is made, becoming less aggressive and harder to flow through the machinery, and both the dry ice and the equipment tend to freeze up when you have a little water in the mix. Both media forms appear to be well suited to restoration works and the removal of charred paints, coatings and odours but are probably less suited to mould remediation in Australia due to construction methods.

Adjunct technologies Sanitisation

Ozone (03) Treatment • Ozone generators create high levels of oxidising ozone that can remove odours including those caused by mould – Generally two methods of generation – Corona discharge and UV light (Photocatalytic oxidation)

• Many products on the market, some fail to meet all expectations

Ozone (03) Treatment • Uses – Odour removal and destruction of residual contaminants and microbial mitigation • For inaccessible areas

• Remediation of odour-damaged vehicles

• Advantages – Cost effective, no reagents required – Oxidiser; reacts with organic matter

Ozone (03) Treatment • Disadvantages – Some generators produce Nitrogen Oxides – Ozone is an eye and respiratory irritant and can cause chronic damage – Damages some materials, eg, natural, nitrile and neoprene rubbers, nylon and low carbon steel

– Typically slow space clearance time

Ozone (03) Treatment • BioSweeptm – also produces other oxygen radicals

• Manufacturers claim 5-15 times more effective than conventional O3 treatment and that the device destroys most biological airborne and residual surface contaminants

Hydrogen Peroxide (H2O2) • H2O2 generators disperse high concentrations of vapour phase H2O2 with resultant non-toxic decomposition products (H2O) – Dry vapour phase, low humidity, use a catalyst throughout operation – Wet phase, normal humidity, may use catalyst at end of operation

• A variety of “Flash Evaporation” generation devices available

Hydrogen Peroxide (H2O2) • Uses – Odour removal and destruction of residual contaminants in inaccessible areas (void spaces and especially interior ductwork) – Recovery of odour-damaged vehicles

– Microbiological mitigation

Hydrogen Peroxide (H2O2) • Advantages – Direct reaction with biological matter with less damage potential than ozone – Quick decomposition results in faster clearance times – Works best in humid environments

• Disadvantages – Higher running costs – Reagents required – Low concentrations are irritating and condensation may harm some products

NocoSpraytm • Nebulisation to achieve “Flash” • Reagent dispersed at start of cycle • Colloidal silver catalyst increases biocidal efficiency • Potential for gross condensation

Bioquelltm • Heater element to achieve “Flash” • Tops up vapour during cycle • Built in catalyst removes vapour at end of cycle • Gross condensation unlikely

. Hydroxyls (OH ) • Hydroxyl radicals are highly reactive and the most potent oxygen based radicals, but have very short half lives • Detractors argue that the brief half life renders them less effective • Proponents suggest that cascade effects and selection of generation method can make them very effective

. Hydroxyls (OH ) • Uses – Odour removal – Rapid knockdown of airborne contaminants – Destruction of residual surface contaminants – Used where unpleasant VOCs and microbiological odours are produced – does not usually require evacuation

. Hydroxyls (OH ) • Advantages – No reagents required – Non-toxic to humans, evacuation not required, and can be run continuously – Greater range of VOC destruction than O3 – Can be used in wet areas – Greater room penetration – No space purge-ventilation required

. Hydroxyls (OH ) • Disadvantages – Seen more as a “polisher” with less kill capacity for residual surface contaminants – Still under evaluation by the Remediation Industry – Some hygienists have raised concern about toxicity of intermediary by-products during dis-association

Questions