Computing partial-shift respirator use periods.

Occasionally, airborne contaminant concentrations cannot be reduced to desired levels, even after the installation of feasible engineering controls. The industrial hygienist may have to recommend full-shift or partial-shift use of appropriate respirators to reduce exposures. The method described allows the industrial hygienist to recommend the minimum period of time an exposed employee needs to use a respirator in order to reach the desired exposure level. The procedure is based on the calculation of Time-Weighted Averages, using the upper confidence levels of air sampling data, and the respirator protection factors.

Safety in the clinical laboratory.

There are many hazards in the clinical laboratory that could result in injury, illness, or loss of property. Many of these hazards are common to the home and a wide variety of working environments; others are unique toi the laboratory. Since control and prevention of occupational illness and injury depends on recognizing their causes and taking timely and appropriate corrective action, this article presents a basic program for protecting the health and safety of clinical laboratorians. It consists of three parts: hazard identification, control measures, and accountability.

A validation procedure for air sampling-analysis systems.

Validation of solid sorbent air sampling-analytical systems used to evaluate employee exposures to substances in the work place air is a fundamental part of any industrial hygiene air sampling program. In April, 1977, the National Institute for Occupational Safety and Health (NIOSH) published "Documentation of the NIOSH Validation tests", as part of the Standards Completion Project. This paper presents an alternative validation procedure which is more easily understood, is more rigorous, and provides for greater accuracy and precision.

A quality control program for analytical procedures using standard additions.

A technique is presented which permits the rapid, simple quality control of analyses that are calibrated by the method of standard additions. The control program is based on the recovery of known amounts of added-in standard material, rather than the direct reading of instrument response.