HAZMAT Technician Practice Exam

The Threshold Limit Value - Short Term Exposure Limit (TLV-STEL) refers to the maximum concentration of a hazardous substance to which workers can be exposed for a short duration, generally considered to be 15 minutes. The accepted standard for exposure to TLV-STEL concentrations allows repeated exposure up to four times a day, provided that there is a minimum recovery time of at least 60 minutes between those exposures. This framework is established to minimize the risk of acute health effects, ensuring that the overall exposure does not exceed what is considered safe for human health.

Understanding this helps to emphasize the importance of properly managing exposure times and recovery periods, particularly in environments where hazardous materials are present. It makes clear that while short bursts of exposure can be tolerated, continuous or exceeding such exposure limits can lead to health complications. Thus, the correct answer effectively captures the recommended frequency of exposure under TLV-STEL guidelines.