Carcinogens

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1. What is a carcinogen?

Over the years, medical research has identified a growing list of hazardous substances and industrial processes which are thought to cause cancer in human beings. These are known as ‘carcinogens’ and are subject to their own specific controls and regulation.

As the list of known carcinogens is always growing, it is best to assume that all chemicals are potentially hazardous and to treat them all with equal respect.

2. What is cancer?

Cancer is a disorder affecting the tissues of the body, particularly the development of new cells. ‘Cancerous’ cells can be either:
 

• benign, remaining localised and not invading neighbouring tissues; or
• malignant, leading to tumours, which can invade and destroy neighbouring tissues or enter blood vessels and other spaces and be distributed to distant parts of the body. Distant tumours (metastases) can cause considerable damage, and it is these which are generally meant by the term ‘cancer’.

3. What types of substance are carcinogens?

The information on hazardous substances will tell you which of them are carcinogenic. The next section gives details of some of the lesser known ones.

Four substances are banned because they are particularly dangerous carcinogens. These are:
 

• 2-napthylamine;
• benzidene;
• 4-aminodiphenyl; and
• 4-nitrodiphenyl.

These substances and their salts can be used or imported only under licence.

4. Where might they be encountered?

You are unlikely to encounter carcinogenic substances in dangerous concentrations, though some types are imported. Bear in mind, though, that some carcinogens are the result of industrial processes, for example:
 

• leather dust during boot- or shoe-making;
• rubber manufacturing and processing;
• work involving coal tar, soot pitch, etc.;
• handling of used engine oils;
• hardwood dusts from woodworking.

You may also encounter asbestos in construction and insulation materials in older buildings and ships.

5. What kinds of cancer can they cause?

It depends. Different types of carcinogen attack different parts of the body, for example:
 

• arsenic and its compounds affect the skin and lungs;
• carcinogenic oils have been linked with scrotal cancer;
• benzene can affect the bone marrow, causing leukaemia;
• aromatic amines (e.g. benzidene and 2-naphthylamine) can cause cancer of the bladder.

Carcinogens can cause damage however they come into contact with the body, whether by inhalation, ingestion or skin contact. It is therefore vital to avoid all direct contact with them.

6. What can be done to reduce the risks?

Always check the Safety Data Sheets. Most carcinogenic products can be sampled safely, using the necessary safety precautions, but sampling of extremely carcinogenic products, such as asbestos, should not be done by Customs officers (See chapter 2.1 of General information on sampling). Most Customs laboratories are not equipped for analysing asbestos. If no SDS is available, do not go ahead with the inspection and sampling until you are certain that you know what the product is and the necessary safety precautions.

If you cannot establish what the goods are and need to proceed with the inspection and sampling, do so only with extreme care and seek expert advice. See Sampling Dangerous and Unknown Goods.

You must refer to the legislation and the guidance of your national administration for more information.
The guidance contained in this section intended to serve as a general reminder of the risks that are sometimes encountered during the examination and sampling procedure and of the safety equipment that you should use and precautions that you should take.