Whenever conditions suggest high exposures or monitoring indicates a potential for overexposure, measures to control exposures should be taken. Control options fall into four categories:
- engineering controls,
- administrative controls,
- control through work practices, and
- personal protective equipment (PPE)
Typically, engineering, administrative, and work practice controls are preferred over PPE when feasible. Since regulatory authorities may differ in their definition of “feasible” controls, employers should contact their respective authority for specific guidelines.
Three categories of engineering controls generally are considered – substitution, enclosure, and ventilation. Of these three options, ventilation is probably the most widely employed as a means of controlling exposures, although it is not necessarily the most effective in all situations. In choosing among options, consideration should be given to the nature of the operation (e.g., is the operation likely to be continuously dusty), the materials handled, feasibility, and regulatory requirements.
When employed, exhaust fans and exhaust ventilation (i.e., exhaust hoods at the source of exposure) are preferred over intake fans for work area ventilation. Ventilation design is complex and should be undertaken only by suitably trained engineers. The designer should consider both the regulations that govern exposure to workplace contaminants and the process operation itself, including the materials being used and the frequency with which they are handled.
Administrative controls, such as employee rotations and workshift modification, can also be used to reduce individual exposures, but such practices should be secondary to engineering controls.
In any industrial setting, it is important to engage in good housekeeping and personal hygiene practices. In the nickel industry, special care should also be taken to reduce the risk of contact dermatitis (e.g., by wearing protective clothing and gloves) and the risk of inhaling nickel in excess of permissible limits. Because smoking is the most common cause of respiratory cancer, it should be discouraged, if not banned.
Personal protective equipment (PPE) ordinarily is the last control option considered. Use of PPE should occur under a properly administered program. When the use of respirators is involved, a written program should be established which describes management and employee responsibilities, respirator selection, fitting, and fit-testing, employee instruction and training, medical screening, and program evaluation. Because recommendations on the use of respirators and other protective equipment may vary from country to country, employers should contact their appropriate authority for guidance.