What your result means

Your result comes as a written report from the laboratory, often called a certificate. They're written for professionals, so they can look technical. This page walks through one, line by line, and explains what to do with each kind of answer.

Who writes it

The laboratory that analysed your sample writes the report, and it's named on every certificate. UK asbestos law requires employers who have samples analysed to use a laboratory accredited to an international standard called ISO 17025, and that's the standard to expect for a home test too. UKAS, the United Kingdom Accreditation Service, is the national body that checks these laboratories. HSE's guide for analysts says the report should carry the UKAS accreditation symbol and number. You can look the number up on the UKAS website.

The analyst uses a method set out in HSE's analysts' guide, HSG248. It combines a low-power microscope search with polarised light microscopy, which shows each type of asbestos fibre by the way it bends and colours light.

What's on the certificate

HSE's analysts' guide lists what a report must include. Expect to see:

• the laboratory's name, address and contact details;
• its UKAS symbol and accreditation number;
• the name of the analyst, and of the person who signed off the report;
• the date and a report number;
• the method used;
• your sample number, so you can match it to what you sent;
• for each sample, whether asbestos was detected, and if so, which type;
• if your sample had layers, such as paint over a coating, which layer the asbestos was in.

Keep the certificate, and keep a note of exactly where each sample came from. A photo of the spot is ideal.

The three answers you might see

"Asbestos not detected"

The analyst searched your sample and found no asbestos fibres. HSE's guide sets a minimum search: about 10 minutes under one microscope, then at least two prepared slides examined for a further 5 minutes at high magnification. Some labs word it slightly differently, such as "no asbestos detected".

It's good news for that sample. It covers the material you sampled, not your whole home. Read what "no asbestos detected" does and doesn't mean.

"Trace asbestos identified"

During that search, the analyst saw only one or two asbestos fibres or fibre bundles. HSE's guide uses the term "trace" for exactly that.

A trace result isn't an all-clear. HSE's analysts' guide defines an asbestos-containing material as one with asbestos "above trace amounts", so a trace result sits on the line. It can mean a material with a very small amount in it, or asbestos dust that has settled on or into a material from something nearby. Treat the material with care, and talk it through with a surveyor before any work that would disturb it. If there's other suspect material close by, that may be the thing to test.

Asbestos detected, with a type

The analyst found asbestos and names the type, or types. The three you're most likely to see are:

• chrysotile (white asbestos);
• amosite (brown asbestos);
• crocidolite (blue asbestos).

Three rarer types are tremolite, actinolite and anthophyllite. The names are minerals, not colours. Read what each type means.

Why there's no percentage

People often expect a figure, such as "3% asbestos". You won't see one, and that's normal. HSE's guide says the method "is not quantitative and percentages of asbestos should not be reported." The analyst's job is to say whether asbestos is there, and which type.

If asbestos was found: what next

Take a breath. Finding asbestos in a home is common, and it's usually manageable. HSE's advice is that asbestos materials in good condition are often best left where they are and checked from time to time. UKHSA says intact asbestos materials in a place where they're unlikely to be disturbed should not cause any harm.

What you do next depends on three things: what the material is, what condition it's in, and what you're planning.

Licensed and non-licensed work

You'll see these words when you look for help.

• Licensed work must be done by a contractor holding an HSE licence. It includes work on sprayed coatings, lagging, loose fill, and most work on insulation board. HSE links to a list of licensed contractors. In Northern Ireland, HSENI publishes its own list.
• Non-licensed work includes most work on textured coatings, floor tiles and asbestos cement. It can be done by a trained tradesperson using careful methods, without a licence.

The type of asbestos on your certificate matters less here than the material it's in. White asbestos in a textured coating is usually non-licensed work. Insulation board needs a licensed contractor for most jobs, whatever type it contains.

If you rent

Tell your landlord or letting agent, in writing, and send them the certificate. Don't start any work that would disturb the material. See renting and asbestos.

If you're worried about your health

If you think you've breathed in asbestos fibres, UKHSA says to seek guidance from your GP or call NHS 111. HSE suggests asking your GP to note the possible exposure in your record.

Questions people ask

Updated 23 October 2026