Deleterious Materials

All materials can be considered deleterious under the wrong circumstances. What are deleterious materials, where are they and how can we help you?
Deleterious Materials

What are deleterious materials?

Deleterious materials are materials or building techniques which are dangerous to health, environmentally unfriendly, those which tend to fail in practice or can be susceptible to change over the lifetime of the material.

Many materials are perfectly acceptable for use in certain circumstances but not for others. With proper care in the selection, regulation and usage of the materials there is often no reason why the materials should not function properly.

  • Early identification and sampling is required to minimise the likelihood of potential exposure to a deleterious or hazardous materials.
  • Risk assessments, control measures and safe systems of work are required by law to reduce risks to health and safety and the environment.
  • Fines and prosecutions are applied for poor safe systems of work, poor risk assessments and ultimately exposure to deleterious materials.
Deleterious Materials

Materials covered

We can offer advice and consultancy on a range of deleterious materials in construction including:


Asbestos is the most written about deleterious material and a class 1 carcinogen; Please see our other blogs and main page for more information on the risks of asbestos and the best asbestos risk management.


Vermiculite itself has not been shown to be a health problem. However, some vermiculite insulation contained asbestos fibres, which can cause problems if inhaled.

Silica Dust

Silica dust is the biggest risk to construction workers after asbestos. Natural substances found in most rocks, sand and clay and in used in products such as bricks and concrete can be hazardous if inhaled. Silica dust materials are widely distributed across the construction industry. Silica dust is released into the air following drilling, grinding and cutting. Exposure to silica dust can lead to the development of lung cancer and silicosis.

Greenhouse Gases (CFC’s, HCFC’s and HCFC’s)

Primarily used in refrigeration and produced by industrial processes. Greenhouse Gases are also used in spray/blown foams used for insulation such as pipe insulation’s and linings to air conditioning units. Also widely used as propellants in aerosols and solvents. Greenhouse gases, such as carbon dioxide, methane, nitrous oxide, and certain synthetic chemicals, they trap some of the Earth's outgoing energy, thus retaining heat in the atmosphere.

Volatile Organic Compounds (VOC’s)

Volatile Organic Compounds were widely used as ingredients in household products such as paints, varnishes and waxes. So do many cleaning, disinfecting, cosmetic and de-greasing products. VOC’s add to issues such as tropospheric ozone and smog in the environment. Common examples of VOCs that may be present in our daily lives are: benzene, ethylene glycol, formaldehyde, methylene chloride, tetrachloroethylene, toluene, xylene, and 1,3-butadiene

Refractory Ceramic fibres (RCF’s) and Man Made Mineral Fibres (MMMF’s)

MMMF's main uses are as thermal insulation. Mineral wools are widely used within the building trade. Refractory Ceramic Fibres main application is as lining material for kilns and furnaces. There are several potential health effects associated with exposure to MMMFs and RCF's, the main effect being irritation to the Respiratory system, effects, such as development of asthma and bronchitis have been noted.


Visual inspection of most solid lead installations is possible, for example lead pipes for water and lead flashing of roof areas. Materials such as paints need samples to be taken and sent to the lab for analysis. Lead poisoning occurs when lead is ingested. Breathing in dust that contains lead, can also cause it. Lead paint surveys & analysis are crucially important for those involved in refurbishment or renovation, particularly in period properties or listed building

Polychlorinated Biphenyls (PCB’s)

Polychlorinated biphenyls (PCBs) are a group of manmade chemicals. They are oily liquids or solids, clear to yellow in colour, with no smell or taste. PCB's were used widely in electrical equipment; capacitors, transformers, fluorescent lights and switchgear because they don’t burn easily and are good insulators. The most commonly observed health effects in people exposed to large amounts of PCBs are skin conditions such as acne and rashes.


If mercury vapour is inhaled, it is easily absorbed by the body, where it first gets into the lungs and from there into the blood and the brain. Mercury is a type of elemental metal found in the Earth's crust that's toxic to humans. If inhaled, mercury vapours can be highly toxic.

Hair Plaster

Historic plaster reinforced with animal hair was sometimes contaminated with the bacterium Bacillus Anthracis which is the causative agent of the disease Anthrax. Inhalation anthrax begins with flu-like symptoms (cough, fever, muscle aches) these can develop into serious lung conditions. Please see our other blogs and main page for more information on the risks of Anthrax.

Polyurethane Foam

The main use for polyurethane foam is for rigid foam boards used for insulation and linings within construction. These can be used as insulation for heating, ventilation and air conditioning systems. Prefabricated PIR sandwich panels are manufactured with corrosion-protected, corrugated steel facings bonded to a core of PIR foam and used extensively as roofing insulation and vertical walls.

Urea Formaldehyde

Urea Formaldehyde was widely used in adhesives, finishes, particle board, medium-density fibreboard (MDF), and moulded objects such as electrical plugs and sockets. Urea Formaldehyde has physical properties of high hardness and high toughness. Widely used as Urea-Formaldehyde Foam Insulation (UFFI) dates to the 1930s and widely made into a synthetic insulation for wall cavities. Formaldehyde can irritate the eyes, skin and respiratory tract and prolonged exposure could cause skin sensitisation