13 Frequently Asked Questions About Asbestos Air Testing and Air Monitoring

While asbestos is a naturally occurring material and was once used in all types of construction, today, it’s recognised as a major health hazard. When asbestos-containing materials (ACMs) are damaged or disturbed, microscopic fibres can become airborne, posing serious health risks if ingested or inhaled.

To keep environments with ACMs safe, air testing and air monitoring are used to ensure the concentration of toxic fibres doesn’t exceed acceptable levels.

Air testing and air monitoring detect and measure the concentration of asbestos fibres in the air. This enables asbestos experts to assess the risk of exposure and, if necessary, determine the next steps to take.

In this article, we’ll answer some common questions about air testing and monitoring to help you better understand the process and ensure everyone’s safety.

asbestos air testing

Asbestos Concentration and Control Limits

Not all ACMs pose a risk of immediate asbestos exposure. Also, while asbestos fibres are dangerous, there is a certain level of asbestos concentration that doesn’t create a health risk.

In this section, we’ll discuss the different control limits for asbestos fibre concentration in the air and what each threshold means.

How many asbestos fibres indicate a risk?

The asbestos risk level is based on the concentration of asbestos fibres in the air. If the concentration is over the control limit of 0.1 fibres per millilitre (f/ml), that indicates a significant risk that requires immediate action.

What are the different levels of asbestos concentration?

When discussing asbestos concentration in the air, two terms that are commonly used are “minimum detectable limit” and “control limit.” Here’s what they mean:

  • Minimum Detectable Limit (MDL): This is the lowest fibre concentration that can be reliably detected by testing equipment. The limit is approximately 0.01 f/ml.
  • Control Limit: The regulatory control threshold is 0.1 f/ml. If the concentration is above this level, rigorous control measures are necessary to prevent asbestos exposure.

Understanding the MDL and the control limit will make it easier to discern the results of the air test.

What happens if the minimum detectable limit or control limit is exceeded?

If asbestos levels exceed the MDL but remain below the control limit — which means they’re detectable but not above the regulatory threshold — the following steps should be taken:

  • Continued monitoring of the air to ensure the asbestos fibre concentration level doesn’t grow.
  • Minor remedial actions may be suggested depending on the situation.

In this scenario, there isn’t enough asbestos concentration to cause alarm, though the situation should be closely watched to mitigate risks.

If asbestos levels exceed both the MDL and the control limit, the following steps must be taken:

  • The area must be immediately evacuated.
  • Remediation work needs to be planned and put into action to reduce the concentration of asbestos in the air.

When the asbestos concentration is too high to be safe, it’s extremely dangerous to delay solving the problem.

Types of Air Tests

There are a few different types of asbestos air tests to know about so you can determine which one best suits your current needs.

What type of air test do I need?

The type of air test that you’ll need depends on your specific situation. Here are the options:

  • Background Testing: This type of air test is done before work begins to establish a baseline.
  • Leak Testing: This type of air test is conducted during asbestos removal to ensure fibres aren’t escaping the containment area.
  • Reassurance Testing: After the removal of asbestos, this type of test confirms that the area is safe for reoccupation.
  • Personal Monitoring: This type of asbestos air test measures the exposure level for asbestos workers.

By speaking with an asbestos expert or having them visit your property for a preliminary assessment, you can figure out which air test is needed.

What is the difference between half-day and full-day testing?

Whether you need half-day or full-day testing depends on the space that needs to be tested, the severity of the asbestos exposure, and other variables.

  • Half-Day Testing: This type of testing is usually suitable for small and/or less complex sites. Shorter tests result in faster turnaround.
  • Full-Day Testing: More time is needed when extensive testing is required. The turnaround time isn’t as fast as with half-day testing because the analysis is more comprehensive.

You may be wondering, “What’s the cost difference between a half-day and full-day test?” Cost varies based on several different factors. However, it’s safe to assume that a full-day test will cost more than a half-day test.

Speaking with an asbestos expert can help you get an idea of what the process will cost.

The Air Testing Process

While asbestos experts will be conducting the air tests, it’s helpful to know what to expect and if you’ll need to relocate until the work is complete.

Does air testing only capture asbestos fibres?

No. During asbestos air testing, various types of fibres that meet the size criteria are captured. This includes all respirable fibres observed under the microscope, as per the standard methods used in the UK (HSG248)​.

How long does asbestos air testing take?

The duration of asbestos air testing depends on the size and complexity of the area being tested. However, a general guideline is that testing will take between 4-8 hours. Based on the site’s conditions, though, it may be shorter or longer than that.

How many air tests are conducted during a visit?

The number of air tests needed depends on the size of the area and the extent of the asbestos contamination.

Typically, we can complete up to 6 air tests in half a day and up to 12 air tests during a full day. The maximum number of air tests that a single asbestos analyst can handle per day is 12.

How long will the asbestos workers be on-site during air testing and monitoring?

Asbestos analysts are usually on-site for the entire duration of the air-sampling process, including the time it takes to get set up. That means workers will be at the site for anywhere from half a day to a full day, based on the scope of work.

However, if the job is simple and only a single air test needs to be conducted, the analyst may only be on-site for approximately 2 hours.

What does the analyst do on-site during asbestos air testing?

Trained asbestos analysts perform several tasks during air testing, including the following:

  • Setting up air-sampling equipment
  • Conducting visual inspections
  • Collecting air samples over a specific period of time
  • Ensuring all safety protocols are followed
  • Conducting an initial analysis and documenting findings

By following these procedures and other essential steps, the analyst makes sure the air test is accurate and that the results are reliable.

Are we allowed to stay on the property during the asbestos air test?

It’s usually safe to remain on the property while air testing is taking place. Air testing doesn’t disturb ACMs, so there’s no risk of more exposure during air testing.

However, it’s best to avoid the areas where testing is being conducted. Not only does this keep everyone safe, but it ensures that the air testing gets accurate results.

Asbestos Air Testing Results

Once air testing is completed, you’ll receive a certificate that shows the test results. Here’s what you should know.

How quickly will I get the results from my asbestos air test?

Results from asbestos air testing are usually available within 24 hours of sampling. In some cases, results may be available immediately and provided shortly after the test is completed.

In general, though, you can expect to receive your air testing results in 24 hours max.

How do I read and understand the air testing certificate?

The air testing certificate will show the concentration of asbestos fibres in the air, expressed as f/ml. This measurement shows the number of fibres detected in the air volume that was sampled.

To understand these results, they have to be compared to regulatory limits. Here’s what to know:

  • Below 0.01 f/ml: This level is considered safe.
  • 01 to 0.1 f/ml: This concentration should be regularly monitored. Minor remedial actions may be best at this stage.
  • Over 0.1 f/ml: This level of asbestos concentration is unsafe, and immediate action needs to be taken.

An asbestos management company will help you decide how to handle the situation if the fibre concentration level is too high.

Final Thoughts About Asbestos Air Testing and Monitoring

In order to maintain a safe environment for yourself and anyone else who occupies or visits a property, air testing and monitoring are essential if ACMs are present.

Our hope is that by addressing frequently asked questions about asbestos air monitoring and testing, we’ve shown how important these procedures are to protect the health of anyone on the property.

For more detailed information about asbestos air testing or to schedule a test, contact Oracle Solutions today. Your safety is our top priority.

13 Frequently Asked Questions About Asbestos Air Testing and Air Monitoring 1

Written by Jess Scott

Jess Scott has been an all-round asbestos consultant since 1996. That’s nearly 3 decades of asbestos knowledge. He spends his time sharing that knowledge with the team at Oracle and with their clients. Jess's goal is, and always has been, to use my expertise in helping people to comply with the law. This legal compliance ultimately helps to protect everyone from the harmful effects of asbestos. Jess has acted as an asbestos expert witness in legal cases and is involved in many asbestos educational activities throughout the UK.