What Your Asbestos Test Results Actually Mean — And What to Do Next
Receiving asbestos test results can feel like being handed a document in a foreign language. Fibre counts, percentage thresholds, analytical method codes — none of it is immediately obvious, and yet every figure carries real legal and safety weight. Those results determine your obligations as a duty holder, shape your management plan, and ultimately protect everyone who sets foot in your building.
This post cuts through the jargon. We’ll explain what every element of a typical results report actually means, how the laboratory figures are produced, and — critically — what you need to do once the report lands in your inbox.
What Asbestos Test Results Actually Contain
A standard asbestos test report is not a simple pass or fail. It gives you a structured breakdown of what was found, where it was found, and at what concentration. Understanding each section is essential before you can act on the findings.
Here’s what you’ll typically see in a results report:
- Asbestos type identified — the report will specify which of the six regulated fibre types were detected: Chrysotile (white asbestos), Amosite (brown asbestos), Crocidolite (blue asbestos), Tremolite, Anthophyllite, or Actinolite
- Fibre concentration — measured in fibres per cubic centimetre (f/cm³) or fibres per millilitre (f/ml)
- Percentage content — the proportion of asbestos fibres within the sampled material by weight
- Sample location — where in the building the sample was collected
- Material description — for example, ceiling tile, pipe lagging, floor tile, or textured coating
- Detection limit — the lowest concentration the laboratory’s method can reliably identify
- Analytical method used — typically Polarised Light Microscopy (PLM) or Transmission Electron Microscopy (TEM)
Each element contributes to the overall risk picture. A result showing trace Chrysotile in undisturbed floor tiles carries a very different risk profile to Crocidolite found in damaged pipe insulation. The numbers only make sense when read in context.
Understanding the Key Numbers: Control Limits and Thresholds
The figures that concern most building owners are the concentration measurements. The Control of Asbestos Regulations set a workplace control limit of 0.1 fibres per cubic centimetre (f/cm³), averaged over a four-hour period. This is the legal ceiling for airborne asbestos exposure in a working environment.
For bulk material samples — the kind taken during a management survey or refurbishment survey — the critical threshold is 1% asbestos content by weight. Any material found to contain 1% or more asbestos is classified as an asbestos-containing material (ACM) under UK guidance and requires formal management or removal.
Materials showing less than 1% may still be recorded in your asbestos register, particularly if the result is close to the threshold or the material is in a deteriorating condition. Your surveyor will advise based on the specific circumstances — this is not a decision to make in isolation.
Reading a Sample Result in Practice
To make this concrete, here are three typical sample outcomes:
- Wall plaster: 2% Chrysotile detected. This exceeds the 1% threshold. The material is confirmed as an ACM and must be included in your asbestos management plan.
- Mortar: No asbestos detected. A clear negative result. No further action is required for this material, though the result should be retained in your asbestos register.
- Ceiling tile: 0.9% Tremolite detected. This falls below the 1% threshold but is close enough that your surveyor may recommend monitoring, particularly if the tiles show signs of damage or deterioration.
These examples illustrate why context matters. The number alone doesn’t tell the full story — the material type, its condition, and its location all affect the risk level and the action required.
The Analytical Methods Behind Your Results
The accuracy of your asbestos test results depends heavily on the laboratory method used to analyse the samples. Two primary techniques are used in the UK, and knowing which one was applied to your samples tells you a great deal about the reliability and precision of the figures.
Polarised Light Microscopy (PLM)
PLM is the standard method for bulk sample analysis in the UK and is used by UKAS-accredited laboratories. It works by passing polarised light through the sample to identify the optical properties of fibres, which differ between asbestos types and non-asbestos materials.
PLM is cost-effective and sufficient for most commercial and residential survey work. It can identify all six regulated asbestos fibre types and provide percentage content estimates. When you order sample analysis through Supernova, PLM is the method applied at our UKAS-accredited laboratory.
Transmission Electron Microscopy (TEM)
TEM is a more advanced technique used when greater sensitivity is required — for example, during air monitoring or when very low fibre concentrations need to be measured precisely. TEM can detect and identify individual fibres at a much finer level than PLM.
TEM is less commonly required for routine building surveys but becomes important in post-removal clearance testing or in situations where occupant exposure is a specific concern. Your surveyor will advise if TEM analysis is warranted for your circumstances.
Why UKAS Accreditation Matters
Always ensure your samples are analysed by a UKAS-accredited laboratory. UKAS accreditation means the laboratory has been independently assessed against internationally recognised standards for technical competence.
Results from non-accredited labs may not be legally defensible and could leave you exposed if your duty of care is ever challenged. This is not an area to cut corners on — the credibility of your entire asbestos register rests on the quality of the laboratory analysis underpinning it.
Steps to Take After Receiving Your Asbestos Test Results
Once your results arrive, the actions you take will depend entirely on what was found. The sequence below applies whether you’ve received results from a full survey or from individual asbestos testing.
If Asbestos Is Confirmed
- Seal off affected areas immediately — if there is any risk of disturbance, restrict access and post clear warning signage
- Notify building users — inform occupants, staff, and contractors of the findings and the areas to avoid
- Consult a licensed asbestos professional — for any ACM at or above the 1% threshold, you need expert advice on management or removal options
- Develop or update your asbestos management plan — this should include the location of all ACMs, their condition, risk ratings, and a schedule for monitoring or remediation
- Arrange air quality monitoring — if there is any reason to believe fibres have been released, airborne fibre testing should be conducted before the area is reoccupied
- Arrange licensed removal or encapsulation — depending on the risk assessment, ACMs may need to be removed by a licensed contractor or encapsulated to prevent fibre release
- Dispose of asbestos waste correctly — asbestos waste is classified as hazardous waste and must be disposed of through licensed waste carriers in line with Environment Agency requirements
If No Asbestos Is Detected
A negative result is good news, but it doesn’t necessarily mean the building is entirely asbestos-free. Surveys involve sampling, not exhaustive testing of every square centimetre of material.
If your survey was a management survey, it covers accessible areas under normal occupation conditions. A demolition survey or refurbishment survey is required before any intrusive works begin, as these access areas that a management survey does not.
Retain all negative results in your asbestos register. They form part of your documented duty of care and demonstrate that you have taken reasonable steps to identify hazardous materials.
Your Ongoing Duty to Manage: Regulation 4 and the Asbestos Register
Receiving your asbestos test results is not the end of the process — it’s the beginning of an ongoing management obligation. Under Regulation 4 of the Control of Asbestos Regulations, the duty holder for any non-domestic premises must:
- Identify the presence and condition of any ACMs
- Assess the risk from those materials
- Prepare and implement an asbestos management plan
- Monitor the condition of ACMs regularly
- Provide information about ACMs to anyone who may disturb them
This is where a re-inspection survey becomes essential. Even if your initial results show ACMs in a stable, low-risk condition, those materials need to be checked periodically — typically annually — to confirm they haven’t deteriorated. Conditions change, buildings get modified, and materials that were intact last year may not be this year.
HSG264, the HSE’s definitive survey guidance, sets out the standards for how surveys and re-inspections should be conducted. All Supernova surveys are carried out in full compliance with HSG264.
DIY Testing vs. Professional Asbestos Testing
Some property owners consider taking their own samples using a testing kit before committing to a full survey. This can be a practical first step for homeowners or landlords who want to check a specific material — a textured coating, for example, or a suspected asbestos cement roof panel.
However, DIY sample collection has real limitations. It is only appropriate where the material can be safely accessed without causing disturbance, and it does not replace a formal survey for duty-to-manage purposes.
If you are responsible for a commercial or public building, or if you are planning any works, you will need a professionally conducted survey rather than individual sample results. For a full picture of the building, asbestos testing conducted as part of a structured survey by a BOHS P402-qualified surveyor provides results that are legally compliant, properly risk-rated, and supported by a written management plan.
How Asbestos Results Interact With Other Building Safety Obligations
Asbestos management doesn’t exist in isolation. If you manage a commercial property, you’ll also have obligations under fire safety legislation. A fire risk assessment is a legal requirement for most non-domestic premises, and the findings of your asbestos survey can be directly relevant to that process — particularly where ACMs are present in areas that might be affected by fire or emergency evacuation.
Keeping both your asbestos register and your fire risk assessment current ensures you have a complete picture of your building’s safety profile. It also allows you to demonstrate compliance across multiple regulatory frameworks — which matters when insurers, regulators, or tenants ask questions.
How Supernova Delivers Your Asbestos Test Results
When you book a survey with Supernova Asbestos Surveys, here’s exactly what the process looks like:
- Booking — contact us by phone or online; we confirm availability and send a booking confirmation, often with same-week availability
- Site visit — a BOHS P402-qualified surveyor attends at the agreed time and conducts a thorough visual inspection of the property
- Sampling — representative samples are collected from suspect materials using correct containment procedures to prevent fibre release during collection
- Laboratory analysis — samples are analysed under PLM at our UKAS-accredited laboratory
- Report delivery — you receive a detailed asbestos register and risk-rated management plan in digital format, typically within 3–5 working days
The report is fully compliant with HSG264 and satisfies all legal requirements under the Control of Asbestos Regulations, giving you the documentation you need to demonstrate your duty of care.
Survey and Testing Pricing
Supernova offers transparent, fixed-price surveys across the UK. Here’s a guide to our standard pricing:
- Management Survey: From £195 for a standard residential or small commercial property
- Refurbishment & Demolition Survey: From £295, covering all areas to be disturbed prior to works
- Bulk Sample Testing Kit: From £30 per sample, posted to you for collection where permitted
- Re-inspection Survey: From £150, plus £20 per ACM re-inspected
- Fire Risk Assessment: From £195 for a standard commercial premises
All prices vary with property size and location. Get a free quote tailored to your specific requirements — no obligation, no hidden fees.
Frequently Asked Questions
What does a percentage figure on asbestos test results mean?
The percentage figure represents the proportion of asbestos fibres within the sampled material by weight. Under UK guidance, any material containing 1% or more asbestos is classified as an asbestos-containing material (ACM) and must be formally managed or removed. Materials below 1% may still be recorded in your asbestos register, particularly if they are close to the threshold or showing signs of deterioration.
What is the legal control limit for airborne asbestos fibres?
The Control of Asbestos Regulations set a workplace control limit of 0.1 fibres per cubic centimetre (f/cm³), averaged over a four-hour period. This is the maximum permissible level of airborne asbestos in a working environment. If air monitoring results exceed this figure, the area must be evacuated and remediated before reoccupation.
Can I collect my own samples and send them for analysis?
Yes, for homeowners and landlords checking a specific material in a domestic property, a DIY testing kit is a practical option. However, sample collection must be done carefully to avoid disturbing the material and releasing fibres. DIY sampling does not satisfy the legal duty to manage for non-domestic premises — commercial and public buildings require a formally conducted survey by a BOHS P402-qualified surveyor.
How long does it take to receive asbestos test results from a survey?
At Supernova, laboratory analysis is conducted at our UKAS-accredited facility and results are typically returned within 3–5 working days of the site visit. The full report — including your asbestos register and risk-rated management plan — is delivered digitally. Expedited turnaround may be available where works are time-sensitive; contact us to discuss your requirements.
Do I need a new survey if my asbestos test results come back negative?
A negative result means no asbestos was detected in the samples taken — but surveys involve sampling, not exhaustive testing of every material in a building. If you’re planning refurbishment or demolition works, a new refurbishment or demolition survey is required even if a previous management survey returned negative results, because these surveys access areas and materials that a standard management survey does not. You should also retain all negative results in your asbestos register as part of your documented duty of care.
For expert advice on interpreting your asbestos test results, or to arrange a survey carried out to HSG264 standards, contact Supernova Asbestos Surveys today. Call us on 020 4586 0680 or visit asbestos-surveys.org.uk to get started.