Asbestos in fire protection: sprayed asbestos, boards, fire doors and seals

Asbestos was used in fire protection because it does not burn and withstands heat. In buildings constructed or renovated before asbestos was banned (2005 at the latest across the EU, and earlier in many countries), asbestos can be found in sprayed insulation (sprayed asbestos), in fireproof boards, inside fire doors and fire dampers, in asbestos millboard in old electrical distribution boards and meter cabinets, and in compounds and rope seals in penetrations and fire stopping. Fire protection material cannot be identified by its appearance, so it is tested from a sample in the laboratory before you drill into it, cut it or demolish it.

In this article we go through where asbestos is typically found in fire protection, why sprayed asbestos is a special case, how to take samples of different fire protection materials and what the result means. Pipe insulation is described on the page Asbestos in pipe insulation.

Where can asbestos be found in fire protection?

Sprayed asbestos

Sprayed asbestos was used, for example, to protect steel beams against fire, to insulate ventilation ducts and to soundproof halls, plant rooms and lift shafts. Sprayed insulation is found mainly in larger buildings such as hospitals, office and public buildings, hotels and factories. The surface can be soft, porous, flaky or granular, and it may be painted over or hidden above a suspended ceiling.

Fireproof boards

Fireproof boards were used in walls and ceilings, especially in industrial buildings and public buildings such as schools, hospitals and shops, but also in stairwells of residential buildings and in ventilation plant rooms. The board may be a hard cement-bonded board, such as asbestos cement, or a lighter, softer insulating board. A soft board breaks and creates dust more easily than a hard one and must therefore be handled even more carefully. Protective boards at fireplaces and sauna stoves are described in the article Asbestos in fireplaces and stoves.

Fire doors and fire dampers

In old wooden fire doors and their frames, asbestos millboard was used as insulation, and asbestos was also used in the fireproof boards of steel doors. The construction of fire dampers should be checked in the same way. From the outside, the door looks like an ordinary metal or wooden door, and the inside cannot be seen without opening the door up. The seals in the door and frame are a separate material.

Electrical distribution boards

Asbestos millboard was used in old electrical distribution boards (fuse boxes) and meter cabinets. The material should be tested before the distribution board is replaced.

Penetrations and fire stopping

Where a pipe, cable or duct passes through a fire-separating wall or floor, the gap is sealed with fire stopping. In old penetrations, compounds, putties, tapes and braided seals were used that may have contained asbestos. The same applies to joint sealants between fire compartments, which are described in the article Asbestos in joint sealant.

Why is sprayed asbestos a special case?

Soft sprayed asbestos is a weakly bound material. Fibres can come loose just from touch, vibration or a draught – unlike, for example, a hard board or an adhesive. That is why it is handled differently from other materials.

• Do not take the sample yourself if the surface is crumbling, dusty or covers a large area. Loose material such as sprayed insulation must also not be sent by post.
• Do not drill through the surface, hang or fix anything to it or open the suspended ceiling below it until the material has been identified.
• If pieces have come loose and fallen on the floor, do not sweep them up or vacuum them with an ordinary vacuum cleaner.
• Inform the owner or property manager so that the situation can be assessed on site.

When is it worth testing fire protection?

Have fire protection tested before work that damages it: replacing fire doors, replacing the distribution board, cable installation and pipework that opens old penetrations or creates new ones, renovating boiler rooms and plant rooms, and opening suspended ceilings in buildings with a steel frame. Remember too that the fire compartments must be restored once the work is complete.

How to take a sample of fire protection material

The basic instructions are the same for all materials:

1. Wear disposable gloves and a respirator of at least class FFP3. Keep other people out of the room.
2. Lightly moisten the sampling spot with a spray bottle to keep dust to a minimum.
3. Hold an open resealable plastic bag under the sampling spot and remove a piece of about 2–5 centimetres through the full thickness of the material.
4. Seal the bag and place it in a second bag.
5. Write the location and material on the bag, for example "Boiler room, inner board of fire door".
6. Cover the sampling spot with tape and wipe the surface with a damp cloth.

Tips by material

• Hard fireproof board: use pliers to nip off a small piece from the edge or corner of the board. Do not saw, drill or sand.
• Soft insulating or fireproof board: use a sharp knife to cut a small piece from the edge straight into the bag. Moisten thoroughly, as the board creates dust easily.
• Fire door or fire damper: do not take the door apart to get a sample. If the edge of the door is already damaged and the inside is visible, take a piece there. Otherwise the door is assessed in a survey or treated as containing asbestos to be on the safe side. The seal is sampled separately.
• Sealing tape or braided seal: use scissors or a knife to cut a piece of 2–3 centimetres straight into the bag.
• Compound in a penetration: use a chisel to remove a small piece of the compound at a spot that is going to be opened anyway. Do not open up the whole fire stopping just for the sample.
• Millboard or board in a distribution board: do not touch a distribution board that is live. The sample may only be taken once an electrician has isolated the distribution board or removed the board.
• Sprayed asbestos: not yourself if the surface is crumbling or dusty. See the instructions above.

You will find more detailed instructions in the articles How to take an asbestos sample and How to protect yourself when taking an asbestos sample.

What does the result mean for the fire protection material?

Semlab analyses the sample with a JEOL SEM-EDS electron microscope in accordance with ISO 22262-1, and you receive the result by email, usually on the same day the sample arrives at the laboratory. The result shows whether asbestos was detected in the sample you sent.

• No asbestos detected: the result applies to the material tested and to identical material in the same building. The board of a fire door, its seal and the compound in a penetration are different materials and are tested separately.
• Asbestos detected: leave the material in place and keep it intact. Demolition, cutting and drilling are planned as asbestos work, and the demolition is carried out by a specialist asbestos removal contractor. At the same time, plan how the fire protection will be replaced with new.

If the fire protection is part of a larger renovation or demolition that requires an on-site asbestos survey, that is done by a surveyor. Semlab is a laboratory and does not carry out on-site surveys.

How much does analysing fire protection material cost?

The analysis costs €49.99 incl. VAT per sample. The price is the same for 1–100 samples. Postage is not included. You can order the analysis online, pay by card and send the sample as a letter or small parcel with your national postal service to the laboratory in Finland.