Posted By Emma Forbes Hi everyone, I'm looking at a product that my brother uses at work, MEKP, and it mentions in the MSDS that it may act as a tumorigen. I haven't come across this phrase before and wondered if anyone could shed some light on it. I see it mentioned next to carciogen and I see it has an OES, but I'm pretty perplexed to what a tumorigen is.

Posted By Kate Graham "Tumorigenic" probably means someone has done some tests in which they have managed to cause tumours in animals, but "carcinogenic" is used as a technical-legal term with stricter criteria. These sorts of tests in animals have limited validity because of the way they are done and finding tumours under the test conditions doesn't necessarily mean the substance can cause cancer in humans under work conditions. The official health risk phrases for MEKP are "harmful if swallowed" and "causes severe burns" (it is also a fire and explosion hazard). It's not classified as carcinogenic. There is no mention of tumours or cancer in the data sheet that I have for an MEKP preparation (yours may be more conscientious). There is often variation in the detail in safety data sheets, partly depending on which country they were written in. But is MEKP a cancer risk? No.

Posted By Emma Forbes Looking at the MSDS I now have, it does mention that it may act as a systematic poison, harmful by ingestion, inhalation and through skin contact and very destructive of mucous membranes......phew! It would be safe assume that using this chemical would need more that your average disposable gloves and nuisance mask that are being provided to my brother. Storing this would also mean that near dodgy light fittings that constantly burn out, is not recommended. Thanks to Kate and Bob for the info.

Posted By Robert K Lewis The gloves are less of a problem as many of the good disposables are edequate but the use of at least a cartridge repirator, subject to other control measures being also in place vis a vis the hierarchy of control, is a minimum level. I personally prefer some form of full facemask or hood with a separate air feed for this. But I am from a school that sampled anhydrous liquid ammonia from the base of a 2000 tonne sphere. The itches in many places, if there were any pinholes, stay in the memory Bob

Posted By Adrian Watson Dear All, The classification "Tumerogen" is not a classification recognised by The Chemicals (Hazard Information and Packaging for Supply) Regulations 2002 SI 2002 No 1689. Carcinogenic Substances and preparations are defined by the regulations as those which, if they are inhaled or ingested or if they penetrate the skin, may induce cancer or increase its incidence. A tumorigen is a substance capable of causing tumours. Tumorigenic: Able to cause tumours. A tumour is defined as any abnormal swelling or growth of tissue, whether benign or malignant; an abnormal growth, in rate and structure, that arises from normal tissue, but serves no physiological function. SN neoplasm. Regards Adrian Watson

Posted By Jonathan Breeze For example... Styrene monomer resin, Cobalt & Acetone (GRP manufacture)