What does TLV-TWA stand for?

• A. Threshold level variable - temperature weighted average
• B. Target limit value - time weighted average
• C. Threshold limit value - time weighted average
• D. Temporary limit value - total weighted average

Answer: (C)

The correct definition of TLV-TWA is "Threshold Limit Value - Time Weighted Average." This term is used in occupational health to indicate the permissible exposure limit to a hazardous substance over a specified period, typically an eight-hour workday. The "Threshold Limit Value" represents a level at which most workers can be exposed without adverse health effects. The "Time Weighted Average" refers to the average exposure level over time, allowing for varying exposure levels throughout the work shift while still maintaining a safe overall exposure rate. This standard helps ensure that workers remain within safe exposure limits, safeguarding their health and safety in the workplace.