What is the IDLH for sulfur dioxide?
Rachel Ellis
Published Jun 22, 2026
What is the IDLH for sulfur dioxide?
100 ppm
Basis for revised IDLH: Based on acute inhalation toxicity data in humans [Henderson and Haggard 1943; Shupe et al. 1972; Tab Biol Per 1933], the original IDLH for sulfur dioxide (100 ppm) is not being revised at this time.
What is the ppm of sulfur dioxide?
Sulfur dioxide is a colorless gas at ambient temperature and pressure. It can be detected by taste at concentrations of 0.35-1.05 ppm and has a pungent, irritating odor with an odor threshold of 0.67-4.75 ppm. It is soluble in water and forms sulfurous acid which is slowly oxidized to sulfuric acid by dissolved oxygen.
What is the IDLH level?
The Immediately dangerous to life or health air concentration values (IDLH values) developed by the National Institute for Occupational Safety and Health (NIOSH) characterize these high-risk exposure concentrations and conditions and are used as a component of respirator selection criteria first developed in the mid- …
What is the ID number for sulfur dioxide?
1079
Chemical Identifiers
| CAS Number | UN/NA Number | DOT Hazard Label |
|---|---|---|
| 7446-09-5 | 1079 | Poison Gas Corrosive |
| NIOSH Pocket Guide | International Chem Safety Card | |
| Sulfur dioxide | SULPHUR DIOXIDE |
What is normal SO2 level in air?
Reported concentrations vary according to the sampling technique. In urban areas typical annual mean values are 10 – 40 µgm-3 (gravimetric sampling) although short-lived pollution episodes such as Bonfire night can cause particulate concentrations to rise to several hundred µgm-3.
Is there a safe level of sulfur dioxide?
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.
How is IDLH calculated?
[Note: A worker breathing at a rate of 50 liters per minute for 30 minutes would inhale 1.5 cubic meters of air.] A “preliminary” IDLH for comparison purposes was determined by dividing these air concentrations by a safety factor of 10….1994 Values.
| t(hours) | correction factor |
|---|---|
| 2 | 1.6 |
| 3 | 1.8 |
| 4 | 2.0 |
| 5 | 2.15 |
Where can I find IDLH?
You can also find IDLH values in CAMEO Chemicals or in the online version of the NIOSH Pocket Guide .
Why is the chemical formula of Sulphur dioxide SO2?
Sulphur dioxide is the chemical compound with a formula of SO ₂. This is because Sulphur dioxide is a compound which has one atom of sulphur and two molecules of oxygen.
What is chemical formula of Sulphuric acid?
H₂SO₄
Sulfuric acid/Formula
What is the IDLH CAS number for sulfur dioxide?
Sulfur dioxide. May 1994. Immediately Dangerous to Life or Health Concentrations (IDLH) CAS number: 7446–09–5. NIOSH REL: 2 ppm (5 mg/m 3) TWA, 5 ppm (13 mg/m 3) STEL. Current OSHA PEL: 5 ppm (13 mg/m 3) TWA. 1989 OSHA PEL: 2 ppm (5 mg/m 3) TWA, 5 ppm (13 mg/m 3) STEL.
What is the OSHA code for sulfur dioxide?
Sulfur dioxide. May 1994. Immediately Dangerous to Life or Health Concentrations (IDLH) CAS number: 7446–09–5. NIOSH REL: 2 ppm (5 mg/m 3) TWA, 5 ppm (13 mg/m 3) STEL. Current OSHA PEL: 5 ppm (13 mg/m 3) TWA.
What is the molecular formula of sulphur dioxide?
Sulfur dioxide PubChem CID 1119 Structure Find Similar Structures Chemical Safety Laboratory Chemical Safety Summary (LCSS Molecular Formula SO2 or O2S Synonyms sulfur dioxide sulphur dioxide Sulfurous
What is a dangerous level of sulfur dioxide?
Sulfur dioxide. With regard to the atmospheric concentration immediately hazardous to life, AIHA [1955] reported that 400 to 500 ppm is considered dangerous for even short periods of exposure [Henderson and Haggard 1943] and that exposure to unendurable concentrations is not necessarily hazardous if escape is made within a few minutes.
