Occupational exposure limits (OELs) are regulatory values which indicate levels of exposure that are considered to be safe (health-based) for a chemical substance in the air of a workplace.

Occupational exposure limits (OELs) are regulatory values which indicate levels of exposure that are considered to be safe (health-based) for chemical exposure at workplaces.

When OELs are absent, according to NIOSH's occupational exposure banding (OEB) can be derived. It allows users to quickly and accurately assign chemicals into specific categories and obtain safe exposure level.

Derived No-Effect Level (DNEL) is a toxicological limit value used as a reference, which enables risk characterization. If, for a given use of a substance, the level of exposure exceeds the DNEL, the risk is out of control; if, on the other hand, the level is below the DNEL, the risk is under control and the substance can be used safely according to the intended conditions.

The purpose of OELs is to prevent or minimize the risk of occupational illnesses, injuries, and other health effects associated with exposure to hazardous substances. In fact employers are legally obliged to provide a working envirnonment that does not endager the health of employees.

They take into account factors such as the toxicity of the substance, the duration and frequency of exposure, and the route of entry (e.g., inhalation, ingestion, skin contact). OELs are often expressed as time-weighted average (TWA) concentrations over a specified time period (e.g., 8-hour workday) or as short-term exposure limits (STEL) for brief periods of exposure, which is typically expressed as milligrams of substance per cubic meter of air (mg/m³) or ppm.

Occupational exposure limits (OELs) are guidelines or regulatory standards that establish the maximum allowable concentration or level of exposure to hazardous substances in the workplace. They are designed to protect the health and safety of workers from the adverse effects of exposure to various chemical agents. These limits may vary from one country to another and may also differ depending on the specific substance or agent being regulated.

• DNEL Calculation
• OEL or OEB derivation
• Expert review of available data
• Exposure risk assessment