What is the PEL for so2?
5 ppm
OSHA: The legal airborne permissible exposure limit (PEL) is 5 ppm averaged over an 8-hour workshift. NIOSH: The recommended airborne exposure limit (REL) is 2 ppm averaged over a 10-hour workshift and 5 ppm, not to be exceeded during any 15-minute work period.
What is dangerous level of so2?
Exposure Effects
| Exposure limits (ppm) | Health Effects |
|---|---|
| 10 | Worsening irritation of eyes, nose and throat |
| 10-15 | Threshold of toxicity for prolonged exposure |
| 20+ | Paralysis or death occurs after extended exposure |
| 150 | Maximum concentration that can be withstood for a few minutes by healthy individuals |
What is OSHA’s 8-hour TWA permissible exposure limit?
25 ppm
During an 8-hour work shift, an employee may be exposed to a concentration of Substance A (with a 10 ppm TWA, 25 ppm ceiling and 50 ppm peak) above 25 ppm (but never above 50 ppm) only for a maximum period of 10 minutes.
What is the STEL for so2?
The ACGIH has a TLV-TWA of 2 ppm and a TLV-STEL of 5 ppm. In the final rule, OSHA is establishing a 2-ppm 8-hour TWA and a 5-ppm 15-minute STEL for SO2. Sulfur dioxide is a colorless, nonflammable gas or liquid with a suffocating odor.
What is the TLV of CO?
OSHA’s former limit for carbon monoxide was 50 ppm as an 8-hour TWA. The ACGIH has a TLV-TWA of 50 ppm with a TLV-STEL of 400 ppm. Carbon monoxide is a flammable, colorless, practically odorless gas. Carbon monoxide readily combines with hemoglobin to form carboxyhemoglobin (COHb).
What is the TWA for H2S?
The new recommendations for airborne H2S exposure are a TWA of 1 ppm and an STEL of 5 ppm.
Why is so2 harmful?
Health effects Sulfur dioxide affects the respiratory system, particularly lung function, and can irritate the eyes. Sulfur dioxide irritates the respiratory tract and increases the risk of tract infections. It causes coughing, mucus secretion and aggravates conditions such as asthma and chronic bronchitis.
What is TLV and STEL?
A: The Threshold Limit Value (TLV(R) ) of a chemical substance establishes the reasonable level to which a worker may be repeatedly exposed, day after day, over a working lifetime without adverse health effects. A Short Term Exposure Limit (STEL) is a TLV(R) based on a 15 minute average.
What is OSHA STEL?
OSHA short-term exposure limits (STELs) are the legal maximum average exposure for a 15-minute time period.
What is TLV?
Threshold Limit Value – TLV (American Conference of Governmental Industrial Hygienists – ACGIH) A chemical substance TLV is the “Workday Concentration” level to which a worker can be exposed to daily for his/her working lifetime without having adverse effects.
What is the difference between TLV-TWA and TLV STEL?
A Time Weighted Average (TWA) is a TLV(R) based on a 8-hour workday and a 40-hour workweek. For example the TWA for carbon monoxide is 25 ppm. A Short Term Exposure Limit (STEL) is a TLV(R) based on a 15 minute average. A Ceiling is a TLV that should not be exceeded during any part of the work experience.
What are the definitions of TLV-TWA and STEL?
The TLV for chemical substances is defined as a concentration in air, typically for inhalation or skin exposure. Threshold limit value − short-term exposure limit (TLV-STEL): A 15-minute TWA exposure that should not be exceeded at any time during a workday, even if the 8-hour TWA is within the TLV-TWA.