The Threshold Limit Value (TLV), established by the American Conference of Governmental Industrial Hygienists (ACGIH), refers to the maximum concentration of a chemical or physical agent in the workplace air to which workers can be repeatedly exposed, day after day, without adverse health effects.

Types of TLV:

• TLV-TWA: Time-Weighted Average (8-hour workday, 40-hour week)
• TLV-STEL: Short-Term Exposure Limit (15-minute exposure)
• TLV-C: Ceiling value — should never be exceeded

Understanding TLVs is essential for occupational health nurses managing industrial settings in Pakistan.