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

Asbestos was used in fire protection because it does not burn and withstands heat. In a building built or renovated before 1994, asbestos can be found in sprayed fire protection, fireproof boards, the core of fire doors and hatches, asbestos paper in old fuse boards and meter cabinets, and the compounds and sealing cords of service penetrations and firestops. Fire protection materials cannot be identified by sight, so they are tested in a laboratory from a sample before anyone drills into them, cuts them or removes them.

This article covers where asbestos typically turns up in fire protection, why sprayed fire protection is a special case, how to sample each type of fire protection material and what the result means. Insulation in general is covered in the article asbestos in mineral wool and insulation.

Where can asbestos be found in fire protection?

Sprayed fire protection

Sprayed asbestos was used, for example, to fireproof steel beams, to insulate ventilation ducts and for sound insulation in halls, plant rooms and lift shafts. It is mostly found in larger buildings such as hospitals, offices, public buildings, hotels and factories. The surface may be soft, porous, woolly or granular, and it may have been painted or hidden above a suspended ceiling.

Fireproof boards

Fireproof boards were used on walls and ceilings, especially in industrial and public buildings such as schools, hospitals and shops, to some extent in the stairwells of residential buildings, and in ventilation plant rooms. The board may be a hard cement-based sheet, covered in the article asbestos cement, or a lighter, softer insulating board. A soft board breaks and sheds dust more easily than a hard one, so it calls for even more care. Protective boards around fireplaces and sauna stoves are covered in the article asbestos in fireplaces and stoves.

Fire doors and hatches

Old timber fire doors and their frames were insulated with asbestos paper, and asbestos was also used in the fire panels of steel doors. Fire-rated hatches are worth checking in the same way. From the outside the door looks like an ordinary steel or timber door, and the core cannot be seen without opening it up. The seals on the door and frame are a separate material.

Fuse boards

Asbestos paper was used in old fuse boards and meter cabinets. It is worth finding out what the material is before the fuse board is replaced.

Service penetrations and firestops

Where a pipe, cable or duct passes through a fire-separating wall or floor, the gap has been sealed with a firestop. Old penetrations were sealed with compounds, putties, tapes and cords that may have contained asbestos. The same goes for the compounds in joints between fire compartments, covered in the article asbestos in sealants.

Why is sprayed fire protection a special case?

Soft sprayed fire protection is a loosely bound material. Fibres can come loose from it with a touch, vibration or a draught, unlike a hard board or an adhesive. That is why it is handled differently from other materials.

• Do not sample it yourself if the surface crumbles, sheds dust or covers a large area.
• Do not drill, hang or fix anything through the surface, and do not open the suspended ceiling beneath it until the material has been identified.
• If pieces have fallen on the floor, do not sweep them up or vacuum them with an ordinary vacuum cleaner.
• Tell the building owner or property manager so the situation can be assessed on site.

If you want to know whether fibres have already reached the indoor air, that is established with an asbestos air sample.

When should fire protection be tested?

Fire protection should be tested before any work that breaks it: replacing fire doors, renewing a fuse board, cabling and plumbing work that opens old penetrations or makes new ones, renovating boiler and plant rooms, and opening suspended ceilings in steel-framed buildings. Remember too that fire separation has to be restored once the work is done.

How to sample fire protection materials

The basic method is the same for every material:

1. Wear disposable gloves and a respirator of at least class FFP3. Keep other people out of the room.
2. Lightly mist the sampling spot with a spray bottle to keep dust to a minimum.
3. Hold an open zip-lock bag under the spot and remove a piece of about 2–5 centimetres through the full thickness.
4. Seal the bag and put it inside a second bag.
5. Mark the bag with the location and material, for example "boiler room, fire door inner board".
6. Cover the sampling spot with tape and wipe the area with a damp cloth.

Material-specific instructions

• Hard fireproof board: nip a small piece off the edge or corner with pliers. Do not saw, drill or sand.
• Soft insulating or fireproof board: cut a small piece off the edge with a sharp knife straight into the bag. Wet it thoroughly, as the board sheds dust easily.
• Fire door or hatch: do not take the door apart to get a sample. If the edge is already damaged and the core is visible, take a piece from there. Otherwise the door is assessed in an on-site survey or treated as asbestos-containing to be safe. The seal is sampled separately.
• Sealing tape or cord: cut off a 2–3 centimetre length with scissors or a knife straight into the bag.
• Penetration compound: chip off a small piece with a chisel at a spot that is going to be opened anyway. Do not open the whole firestop just to take a sample.
• Paper or board in a fuse board: never touch a live fuse board. The sample can only be taken once an electrician has isolated the board or removed the material.
• Sprayed fire protection: not yourself if the surface crumbles or sheds dust. See the guidance above.

More detailed instructions are in the articles how to take an asbestos sample and how to protect yourself when taking an asbestos sample yourself.

What does the result for a fire protection material mean?

Onelab analyses the sample with a JEOL SEM-EDS electron microscope in accordance with ISO 22262-1, and the result is sent by email, typically on the day the sample arrives. The result tells you whether asbestos was detected in the sample you sent.

• No asbestos detected: the result applies to the material tested and to the same material elsewhere in the building. A fire door board, its seal and a penetration compound are different materials and are tested separately.
• Asbestos detected: leave the material in place and keep it intact. Removal, cutting and drilling are planned as asbestos work, and the removal is carried out by a company authorised for asbestos removal work. At the same time, plan how the fire protection will be replaced.

If the fire protection is part of a larger renovation or demolition that requires an on-site asbestos survey, the survey is carried out on site by a qualified surveyor. Onelab is a laboratory, and on-site surveys are handled by our sister brand AsbestiPro.

How much does the analysis of a fire protection material cost?

The analysis costs €39.90 + VAT per sample, and the price is the same for 1–100 samples. Orders of more than 100 samples can be priced separately. Postage is not included. You can order the analysis online and send the sample to the laboratory by post.