Health & Safety

• Control of Substances Hazardous to Health
• Preventing or Controlling Exposure
• Working with toxic substances

Control of Substances Hazardous to Health

The Control of Substance Hazardous to Health (COSHH), are the main piece of legislation covering control of the risks to employees and other people arising from exposure to harmful substances generated out of or in connection with any work activity. The main objective of the Regulations is to reduce occupational ill health by setting out a simple framework for controlling hazardous substances in the workplace.

As with all other regulations building on the Health and Safety at Work legal duties are laid primarily on employers and it is their duty to see that proper systems of work and management are in place. In higher education, the "employer" is taken to be the governing body of the University e.g. the University Council. Many of the duties that employers owe to their employees extend to non-employees, such as students, who may be affected by the employer's activity. In particular, students and other non-employees need to be given information and training on how to deal with hazardous substances they may encounter in the course of their work or study within the University. Duties on employees include making proper use of any control measures, following safe systems of work, abiding by local rules and reporting defects in safety equipment.

Assessment

"Suitable and sufficient" assessment includes determining the hazardous substances that are likely to be encountered, thinking about the risks they present to health, asking how much and how often the substances are used, how hazardous they are and what are the exposure routes and finally deciding on the action needed to prevent exposure or to reduce it as far as is reasonably practicable.

Preventing or Controlling Exposure

Employers must ensure that the exposure of employees to hazardous substances is either prevented (i.e. no exposure) or adequately controlled. If it is reasonably practicable, exposure must be prevented by changing the process or activity so that the hazardous substance is not required or generated, or replacing it with a safer alternative (especially important if the substance is a carcinogen), or using it in a safer form. If prevention is not reasonably practicable, exposure must be adequately controlled by one or more of the measures outlined in the Regulations e.g. total enclosure of the process, suitable ventilation etc. Adequate control also means having systems in place to deal with emergencies, spills and disposal. Only as a last resort should personal protective equipment be used as a means of protection. (However, the routine wearing of laboratory coats and safety glasses is generally regarded as a basic measure to minimise risks from foreseeable hazards - it is not reasonably practicable to provide other means of protection for workers and especially for their eyes.)

Ensuring that Control Measures are Used and Maintained

Employees are required to make proper use of control measures (e.g. fume-hoods) and to report defects and employers must take all reasonable steps to ensure that they do so. Employers must also ensure that the equipment is kept in efficient working order and good repair and that it is tested regularly.

Working with toxic substances

Many toxicity data are incomplete so great care should be taken in cases of uncertainty. Hazard warning labels are frequently provided by suppliers of laboratory equipment and chemicals. The extent of personal protection necessary will vary according to the nature of the experiment. Safety spectacles and lightweight disposable gloves should be worn at all times, along with buttoned up laboratory coats. High-necked buttoned gowns must be worn for microbiological work. Heavy-duty leather gloves should be worn either for ultra low temperature work or for handling highly corrosive liquids. The main physical danger in laboratories comes from fire and smoke, from explosion of volatile solvents and gases, from vacuum implosion of glass vessels, from sources of ionising radiation, from lasers and ultraviolet light and from ultrasonic vibration. Potential biological hazards also arise from work with laboratory animals. Work with either tissue cultures or microorganisms should, therefore, take place inside safety cabinets in which a sterile air flow moves vertically away from the operator. Manipulative skills in aseptic technique are absolutely essential for all experiments using such models. Despite even the most stringent attention to good safety practice, accidents do happen and it is very important to have available qualified first-aiders to deal with emergencies. Key telephone numbers for emergency services should be clearly and conveniently posted. The disposal of unused chemicals, radioactive isotopes and infected material should be subject to clear procedural guidelines and detailed records kept of such disposals. Corrosive chemicals such as acids and alkalis must be neutralised before being washed away down the sink. All organic solvents must be stored in metal drums, with chlorinated solvents stored separately, before chemical incineration at high temperature. Radioactive waste, in particular, is subject to stringent disposal regulations that are legally enforceable. All spent or contaminated tissue or cell cultures or microbial cultures must be sterilised by autoclaving before disposal.