What Does Short-Term Exposure Limit (STEL) Mean?
Short-term exposure limit (STEL) is the acceptable exposure limit to a toxic or an irritant substance over a short period of time (time-weighted average), usually 15 minutes. STEL is the maximum concentration of a chemical to which workers may be exposed continuously for a short period of time without any danger to health, safety or work efficiency. This term is used in occupational health, industrial hygiene and toxicology.
Short-term exposure limit may also be known as short-term exposure value (STEV).
Safeopedia Explains Short-Term Exposure Limit (STEL)
The Occupational Safety and Health Administration (OSHA) has set short-term exposure limits for 1,3-Butadiene, benzene and ethylene oxide. For chemicals, STEL assessments are usually done for 15 minutes and expressed in parts per million (ppm), or sometimes in milligrams per cubic meter (mg/m3).
In general, a short-term exposure limit appears on a Manufacturers Safety Data Sheet, which includes safety information about the substance in question. When working with materials that have exposure limits listed on them, one should use proper precautions to minimize the generation of vapors or dust. Always use appropriate personal protective equipment or (PPE) such as gloves, dust masks, and respirators to minimize exposure to chemicals.
Exposure limits are not an absolute threshold that defines the border between safe and dangerous. For example, a STEL that was acceptable in the 1990s may be recognized as dangerously high today.