Faculty of Science

Department of Chemistry

Use of Carcinogens, Mutagens and Substances Toxic to Reproduction

Throughout this Risk Assessment the word "Carcinogenic" is used to cover materials that are carcinogenic, mutagenic or toxic to reproduction.


High risk of premature death.

Detailed information about carcinogens, mutagens and substances toxic to reproduction are given under Chemical Hazards and in the documents covering CHIP and COSHH.


Prevention of Exposure

As usual for hazardous materials, the first route of protection is to avoid exposure totally by using a safer alternative. If such an alternative is available and its use is "reasonably practicable" then this must be done. However, carcinogenic, toxic and other properties of possible chemical substitutes should be established and taken into account when considering changes. Synthetic routes should be chosen to avoid the use of carcinogenic starting materials and to avoid, as far as possible, the formation of by-products, intermediates, wastes or residual contaminants consisting of or containing carcinogenic substances.

However, if there is no practicable alternative to using a carcinogenic substance then a COSHH Special Assessment must be completed for that substance in written form, including a justification for the use of that substance and a copy of the Assessment lodged with the Departmental Safety Committee.


Control of Exposure

If use of a safer alternative substance is not reasonably practicable, then adequate control of exposure must be ensured. In the case of carcinogens, it is particularly important that exposure should be controlled to as low a level as is reasonably practicable, bearing in mind the high risk of death associated still with many forms of cancer and the fact that the level of exposure affects only the probability of cancers occurring in any exposed population and not the severity of the disease in individuals.

In addition to the principles of Good Laboratory Practice laid down in the COSHH Standard Assessment, the following rules must also be applied or more strongly emphasised:

  • All users of carcinogens must be fully aware of the hazards associated with using the substance and of the route(s) by which the particular carcinogenic substance(s) can enter the body, be it by inhalation, ingestion or by penetration of the skin, mucosal surfaces or eyes. This will require a thorough reading of Safety Data Sheets and other sources of information.
  • The preferred method of controlling exposure is by total containment of the substance or process. This is unlikely to be possible in a research environment but must be employed if reasonably practicable.
  • The number of people likely to be exposed to a carcinogenic substance and the duration of their exposure must be kept to a minimum.
  • Only the minimum amount of carcinogenic substance necessary may be used. This applies also to stored material which should be kept to a minimum.
  • Carcinogenic materials must be stored in closed containers that are clearly labelled and marked with visible hazard and warning signs. Preferably, all carcinogenic substance containers should be stored in locked, ventilated cupboards fitted with trays to contain spillage and clearly marked with warning and hazard signs.
  • Carcinogenic materials that are normally stored in glass containers may be transported only within robust, secondary containers large enough and capable of containing any spills arising from breakage.
  • Carcinogenic material may be used only within a fume-hood of good quality and effectiveness.
  • The appropriate protective clothing must be worn including gloves of material that provide real protection against accidental skin contact.
  • Great care must be taken to avoid spreading contamination from the site of use. This will involve the following precautions:

    • Material may be weighed only within an adequate fume-hood or other well ventilated enclosure,
    • Care must be taken to avoid contaminating the exterior of containers. Any such contamination must be cleaned off within the fume-hood before returning to store and the cleaning material disposed of as carcinogenic waste,
    • Care must be taken to avoid the formation of airborne dust or processes that may give rise to aerosols,
    • Apparatus must be cleaned within the fume-hood and any washings, including solvent, carefully stored as waste. Alternatively, any carcinogenic residues may be chemically destroyed- if so, the procedure for destruction must be written down as part of the COSHH Assessment,
    • Spill etc. within the fume-hood must be cleared up carefully and any materials used disposed of as carcinogenic chemical waste,
    • Gloves must be disposed of as carcinogenic chemical waste. Users must never touch door handles, light switches or telephones with (assumed contaminated) gloves or wear such gloves outside of the laboratory. Gloves should be removed using the proper "surgical" procedure to avoid skin contamination,
    • Users must practice careful hygiene and wash and dry hands thoroughly before leaving the laboratory.
  • The use of "sharps" in procedures should be avoided because of the additional danger of self- injection. Disposable "sharps", including broken glass must be decontaminated before disposal and the washings treated as carcinogenic chemical waste.
  • Waste material must be securely stored and clearly labelled prior to disposal. Carcinogenic materials must never be disposed off by the waste solvent route.



The greatest care should be taken to avoid any spills of carcinogenic materials outside of the fume-hood or ventilated area. If this does occur, it is necessary to evacuate the area, close all doors and warn others of the danger. The PSSO (ext 2691) must also be informed.

Failure of Services

Work should be carefully closed down, gloves removed and left, the fume-hood sashes closed and the laboratory evacuated until services are resumed.

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Adapted with permission from School of Chemistry, University of Bristol