Work-related cancer update

Work-related cancer update

Work-related cancer update –  summary of a discussion at a WMHT public meeting, led by Hillary Cross, industrial toxicologist

Background explanation

Some technical titles

Carcinogen: name for any substance which causes cancer, many of which are found at work.

Mutagen: changes genetic structure (most mutagens cause cancer). They pose a risk to the reproductive system and hence also to future generations.

For carcinogens and mutagens, there is no safe level in the air. Regulations state that carcinogens and mutagens should be eliminated altogether, rather than just reduced to the lowest levels like other toxic chemicals, if a safer substitute can be found.

Carcinogens relevant to people at work and in the environment, once researched by them, are classified by the International Agency for Research into Cancer (IARC) into the following categories:

Group 1           Carcinogenic to humans

Group 2A         Probably carcinogenic to humans

Group 2B         Possibly carcinogenic to humans

Group 3           Not classifiable as to its carcinogenicity in humans

Group 4           Probably not carcinogenic to humans

Despite these classifications, there is no internationally recognised, mandatory agreement on how to put this knowledge into practice. Governments vary as to how they approach this in law, and there is much controversy over what ought to happen. The job of safety reps and Hazards activists is to raise awareness so that as much as possible can be done by putting people before profits, by using the available knowledge, such as the actual IARC classification given to carcinogens.


An example is that diesel fumes was recently given a Group 1 classification as a definite, proven carcinogen. We need to make people aware of this. In the UK, there is a duty on employers to carry out risk assessments in areas where proven carcinogens have been identified, so that the risk can be eliminated. Nevertheless, at the time of writing, the information on the HSE website for diesel fumes did not include this vital piece of information on the new classification! Safety reps need to raise such issues at work, and we need to spread the word.

Another example is that glyphosate (the active ingredient in “Round-up” weedkiller and similar products) was given a Group 2A classification as a Probable Carcinogen. Despite its wide usage industrially and domestically, there is much debate as to what should be done in practice.

New EU Pictograms include one which spells out that something is a carcinogen, rather than just listing “irreversible effects” as it used to do.

For example, a carcinogen, say one in liquid form, could say, along with the current symbol for a toxic substance: “May cause cancer by inhalation” and include the IARC group of known carcinogenicity as explained above.

It used to be that, legally speaking, financial costs don’t come into the cost-benefit equation when deciding on steps to take to control risks from carcinogens, but now they can. This means that the human costs have become secondary to the financial costs.  

A database called CAREX (carcinogen exposure) was compiled to provide documented estimates of the numbers of workers exposed to carcinogens in the EU, by country, carcinogen and industry. They looked at the top IARC categories and found substantial exposures to carcinogens such as wood dust, crystalline silica, and diesel fumes.

At the moment, the UK and Europe work to a precautionary principle, so suspect substances should be treated as toxic until proved otherwise, but the US does not i.e. evidence has to be overwhelming first. International trade agreements like TTIP, when implemented, would mean a “race to the bottom” so little would be done to prevent deaths and disease until far too late. Such moves need to be challenged. Also, moves to cut safety reps’ rights, such as the current TU Bill, also need to be challenged, if they are to be able to raise such issues. Similarly, current laws making it harder to prove employers’ liability, such as the Enterprise Bill, need to be opposed.

One current debate is around the toxicity of mixtures of toxic substances, some of which may be more toxic than the individual substances alone. See the European Chemical Agency’s explanation of their current thinking. 


Filed under: Cancer