OVERVIEW
Asbestos contamination on surfaces, whether from improper removal, accidental release, or residual contamination, poses significant health risks to workers and building occupants. While there are currently no regulatory criteria for acceptable asbestos levels on surfaces, assessing and managing this risk is crucial to ensure a safe working environment. WHS’ Industrial Hygienists specialize in identifying and mitigating these risks using advanced testing methods and tailored control strategies.
WHS Specialization in Asbestos Surface Contamination Management
At WHS, our Industrial Hygienists are highly experienced in assessing asbestos contamination on surfaces. We utilize standardized testing methods developed by ASTM International to accurately detect asbestos fibers and provide expert guidance on effective risk management. Our team has the expertise to perform comprehensive assessments and implement appropriate controls to protect workers and building occupants from potential asbestos exposure.
ASTM Methods for Surface Sampling
- ASTM D6480-05: Wipe Sampling for Asbestos Structure Number Concentration
- Purpose: This method is used to sample dust on surfaces by collecting asbestos structures through wipe sampling. The collected sample is then analyzed by Transmission Electron Microscopy (TEM) to determine the number concentration of asbestos structures.
- Applications: It is particularly useful for assessing contamination levels on smooth, non-porous surfaces and for evaluating the effectiveness of asbestos abatement by comparing pre- and post-abatement samples.
- ASTM D5756-03: Microvacuum Sampling for Asbestos Mass Surface Loading
- Purpose: This method involves the use of a micro-vacuum to collect dust samples from surfaces, followed by indirect analysis using TEM to measure the asbestos mass surface loading.
- Applications: This method is well-suited for sampling from rough or porous surfaces, such as carpets, upholstered furniture, and other soft goods, providing a measure of the total asbestos mass present on a surface.
Risk Assessment and Required Controls
If asbestos fibers are detected on surfaces, a competent person must conduct a risk assessment to determine whether there is a potential worker exposure issue. The following risk assessment matrix, based on WorkSafeBC and Alberta guidelines, helps to determine the required controls based on the risk of exposure:
- Minimal Risk: Background levels of asbestos. No specific controls are required beyond standard housekeeping.
- Low Risk: Defined as Low Risk 1 or Low Risk 2 according to WorkSafeBC or Alberta definitions. Basic controls, such as wet wiping and HEPA vacuuming, are recommended.
- Moderate Risk: Contamination levels that require containment and controlled work practices. Use of half-mask respirators or powered air-purifying respirators (PAPR) may be necessary.
- High Risk: Significant asbestos contamination that requires strict controls, including full containment, dry removal techniques, and the use of supplied air respirators.
Implementing Controls Based on Risk Levels
- Minimal and Low Risk: Conduct routine cleaning using HEPA-filtered vacuums and wet wiping. If wipe sampling is being used to verify cleaning, ensure samples are taken both before and after cleaning.
- Moderate Risk: Implement containment strategies to prevent the spread of fibers. Ensure that workers use appropriate personal protective equipment (PPE), such as PAPR or half-mask respirators, and establish decontamination procedures.
- High Risk: Full containment and use of supplied air respirators are required. Review and adjust work practices to minimize fiber release and ensure all surfaces are thoroughly cleaned and decontaminated.
Compliance and the Role of the Qualified Person
Managing asbestos surface contamination requires compliance with relevant regulations and guidelines. Our team at WHS includes qualified persons who are trained and experienced in:
- Interpreting sampling results accurately.
- Conducting thorough risk assessments.
- Developing and implementing effective control measures tailored to each unique situation.
WHS Expertise in Evaluating Asbestos Abatement Effectiveness
WHS Industrial Hygienists are skilled in using wipe sampling to evaluate the effectiveness of asbestos abatement. Our process includes collecting samples before and after abatement activities to confirm that asbestos fibers have been effectively removed and that no contamination remains outside the abatement area. If asbestos fibers are detected on surfaces outside the containment zone, we will assess the extent of contamination and recommend appropriate cleanup and work practice modifications to prevent further contamination.
Why Choose WHS?
WHS’s Industrial Hygienists are uniquely qualified to handle asbestos surface contamination issues. We bring a wealth of expertise in identifying, assessing, and managing asbestos risks using the latest testing methods and industry best practices. Whether you're dealing with a complex remediation project or need to evaluate the effectiveness of an asbestos abatement, WHS can provide the specialized support and solutions required to ensure safety and compliance.
For more information on how we can assist with your asbestos surface contamination concerns, please contact us to speak with one of our experienced consultants.
For more information on how we can assist with your asbestos surface contamination concerns, please contact us to speak with one of our experienced consultants.