Which of the following is not a recognized TLV designation?

Which of the following is not a recognized TLV designation?

• A. TLV-TWA
• B. TLV-STEL
• C. TLV-C
• D. TLV-PS

Answer: (D)

Threshold Limit Values (TLVs) are guidelines that indicate exposure limits for workers, with each designation describing how the limit is applied over time. The common ones are TLV-TWA, which sets a permissible average exposure over an 8-hour workday; TLV-STEL, which sets a short-term (typically 15-minute) exposure limit; and TLV-C, the ceiling limit, which should never be exceeded at any time. A designation like TLV-PS isn’t part of the standard TLV set used by typical occupational exposure guidelines, so it isn’t recognized. That’s why TLV-PS is the correct choice for “not a recognized TLV designation.”

Threshold Limit Values (TLVs) are guidelines that indicate exposure limits for workers, with each designation describing how the limit is applied over time. The common ones are TLV-TWA, which sets a permissible average exposure over an 8-hour workday; TLV-STEL, which sets a short-term (typically 15-minute) exposure limit; and TLV-C, the ceiling limit, which should never be exceeded at any time. A designation like TLV-PS isn’t part of the standard TLV set used by typical occupational exposure guidelines, so it isn’t recognized. That’s why TLV-PS is the correct choice for “not a recognized TLV designation.”