ABC of Safety in the Biological Sciences
Paraffin: (Also see Paraffin Wax) Wax is a mixture of hydrocarbons which are flammable, therefore every care should be taken when applying heat. Ideally paraffin baths should have three thermostats so that if one fails another will maintain the temperature. This avoids the risk of overheating and possible combustion of the wax. Waxes should not be heated over a naked flame as this can cause a hot spot in the wax which may ignite. Heating through a sand bath is recommended. Overheating wax can also cause some additives to emit toxic fumes.
Resins: Resins may cause contact dermatitis and some are said to be potential carcinogens. The liquid and vapour are eye, skin and respiratory tract irritants. They are also incompatible with strong oxidising agents, mineral acids, bases and amines while heating produces toxic fumes. Disposable gloves should be worn during all stages of resin embedding. Processing and embedding procedures are best carried out in a fume cupboard. Excess resin should be allowed to polymerise before disposal by high-temperature incineration.