Threshold Limit Value (TLV) – Definition and Pronunciation
What is TLV?
Threshold limit value (TLV) Concentration of gases in air to which it is believed personnel may be exposed 8 hours per day or 40 hours per week throughout their working life without adverse effects. The basic TLV is a Time-Weighted Average (TWA) and may be supplemented by a TLV-STEL (Short-Term Exposure Limit) or TLV-C (ceiling exposure limit, which should not be exceeded even instantaneously).
Examples of TLV
Maximum threshold limit value (TLV) for ammonia concentration, based on an eight (8) hours per day exposure, is 50 ppm (35 mg/m3). The threshold limit value of ammonia concentration, which is hazardous after an hour exposure is equal to 500 ppm.
Sulfur dioxide produces irritation of the eyes, nose and throat and may also cause breathing difficulties in sensitive people. It has a distinctive smell at its TLV of 2 PPM.
From “Knowledge and understanding of tanker safety culture and safety management”.
The most widely quoted OEL system is that of the American Conference of Governmental Industrial Hygienists (ACGIH), which uses the term threshold limit value (TLV), but OEL systems from advisory bodies in other countries are generally similar in structure.
From “Basics of Safety on Gas Carriers”.
Pronunciation of TLV
