RICS Draft Guidance Note: Asbestos - legal requirements and best practice for property professionals and clients (4th edition)

RICS Asbestos 4th edition consultation draft

Appendix A: Common asbestos-containing materials

Asbestos has many useful properties that have encouraged its use in buildings and plant. These include its great tensile strength; its non-combustibility; its resistance to heat, fire, electricity and chemical attack; its ability to be incorporated with and to bind other materials; and its relative cheapness and availability.

Consequently, it has been extensively used in almost all types of building - residential, commercial and industrial - throughout the world, and in a wide variety of situations and forms.

As well as being utilised for a wide variety of purposes, it has been applied and installed in a variety of ways, whether hand-applied as in the case of pipe lagging, fixed with adhesive (floor tiles) or sprayed (fire protection to steelwork).

The asbestos content of materials has also varied, depending on the reason for the asbestos being added in the first place. Lagging materials contain more asbestos, particularly if used around steam applications, so these products might have a content of up to 80% asbestos fibre. However, if the asbestos was being added as a binder or strengthener, the content only needed to be relatively low, around 10%.

The type of fibre used is also important. Crocidolite (blue) and amosite (brown) can withstand higher temperatures, so were found in lagging materials as well as AIB. Chrysotile (white) was more suited to use as a binder, so is the more common fibre type in cement products, plastics, resins and textured coating.

Crocidolite and amosite asbestos continued to be used in the UK until they were banned in 1985. It was at this point that asbestos use started to decline, although chrysotile (white) asbestos was not banned until November 1999 (May 2000 in Northern Ireland). During the 1990s, clients wanted asbestos-free new-build constructions, and The Construction (Design and Management) Regulations 1994 introduced the idea of eliminating foreseeable health and safety risks in buildings from the design stage onwards.

The proportion of asbestos in different ACMs varies greatly and the proportion generally relates to its purpose. When present in small proportions, around 10%, it serves as a binding agent, but when present in larger proportions, over 15%, it serves as insulation (thermal or acoustic). The higher the proportion of asbestos, the greater the friability of the material.

Asbestos fibres range in size from those visible to the naked eye to very fine fibres measuring a few microns. Fibres that are visible to the naked eye are not composed of a single fibre but multiple fibres in a bundle.

Disturbing asbestos will release very fine fibres that have the ability to penetrate deep into the lungs. Because of the chemical and physical characteristics of the fibres, they cannot easily be expelled from the body and are not easily broken down. Asbestos fibres are termed bio-persistent and have the potential to accumulate in the body.

The table below explains more about the common groups of asbestos products.

Product

Use

Dominant fibre type

Approx. date of last use

Loose

Mattresses/quilts for fire stopping and sound insulation

Crocidolite or chrysotile

1970s

Sprayed coating

Dry or wet applied anti-condensation or acoustic insulation, structural fire protection

All types

Mid-1970s

Thermal insulation

Pipes, boilers, pressure vessels, calorifiers

All types

Early 1980s

Asbestos insulating board (AIB)

Fire breaks, infill panels, partitions, ceilings, ceiling tiles, linings to roofs and walls, external canopies and porch linings

Amosite

Mid-1980s

Millboard

Fire protection, heat and electrical insulation

Chrysotile

Late 1970s

Paper, felt, cardboard

Reinforcement and lining of other products

Chrysotile

1980s

Ropes and yarns

Jointing and packing; boiler, oven and flue sealing; plaited tubing in electric cables

Chrysotile

1980s

Cloth

Fire blankets, mattresses, curtains, gloves

Chrysotile

1980s

Gaskets and washers

Hot water boilers for industrial power and chemical plant

Chrysotile

1990s

Strings

Seals for radiators

Chrysotile

1980s

Resin-based materials

Brake linings and clutch pads in machinery and lifts

Chrysotile

1990s

Drive and conveyor belts

Engines and conveyors

Chrysotile

1990s

Profiled sheets

Roofs, wall cladding, permanent shuttering

Chrysotile

1990s

Semi-compressed flat sheets

Bath panels, soffits, walls, ceiling linings, weather boarding, composite panels for fire protection or base for decorative facings

Chrysotile

1990s

Fully compressed flat sheets

Worktops, imitation roof slates

Chrysotile

1990s

Pre-formed moulded products

Troughs and conduits, tanks, drainpipes, flues, rainwater goods, window sills and reveals, fascias, soffits, ducts, copings, promenade tiles, early imitation slates

Chrysotile

1990s

Textured coatings

Decorative coatings on ceilings and walls (Artex)

Chrysotile

Late 1980s

Flooring

Floor tiles (Marley type)

Chrysotile

Mid-1980s

Bitumen products

Roofing felt, damp-proof courses, flooring adhesive, sink pads

Chrysotile

Early 1990s

Reinforced plastics

Toilet cisterns

All types

1980s

Table 3: Common groups of asbestos products

Many asbestos products had different mixtures of fibres depending on availability of stock, so dominant fibre type should only be used as a general guide.

Recent incidents of imported components, classed as 'asbestos-free' but containing a small quantity of asbestos, have been confirmed. The approximate date of last use should therefore only be taken as a guide for UK manufacture.