Sulphuric Acid Plant Safety - Sulphur Dioxide
November 3, 2003

Introduction Respiratory Protection Eye/Face Protection Protective Clothing Safety Signs

Associated Links

---

Introduction

Sulfur dioxide is a colourless gas with a pungent, irritating odour similar to burning sulfur.  It is a colourless liquid below -10 deg C.  Sulfur dioxide will not burn.  It is a COMPRESSED GAS.  Cylinders or tanks may rupture and explode if heated.  It is VERY TOXIC and may be fatal if inhaled.  Sulfur dioxide is also extremely irritating to eyes and respiratory tract.  It causes lung injury and these effects may be delayed.  It may also cause frostbite.

Respiratory Protection

Condition	Protection
Up to 20 ppm	- Chemical cartridge respirator with cartridge(s) to protect against sulfur dioxide - Supplied-air respirator
Up to 50 ppm	- Powered air-purifying respirator with cartridge(s) to protect against sulfur dioxide - Supplied-air respirator operated in a continuous-flow mode
Up to 100 ppm	- Full-facepiece chemical cartridge respirator with cartridge(s) to protect against sulfur dioxide - Gas mask with canister to protect against sulfur dioxide - Powered air-purifying respirator with a tight-fitting facepiece and cartridge(s) to protect against sulfur dioxide - Full-facepiece self-contained breathing apparatus - Full-facepiece supplied-air respirator - Supplied-air respirator with a tight-fitting facepiece operated in a continuous-flow mode

Eye/Face Protection

To protect your eyes from sulphur dioxide, chemical safety goggles must be worn at all times in designated areas.  A face shield may also be necessary when working in the presence of sulphur dioxide.

Protective Clothing

Guidelines for protective clothing for possible exposure to sulphur dioxide.

> 8 hour Recommended	> 4 hour Recommended	< 1 hour Not Recommended
Saranex™ Responder® Barricade®	Teflon™	Polyethylene

Notes:
1. Recommendations are valid for permeation rates reaching 0.1 µg/cm²/min or 1 mg/m²/min and over.  Resistance of specific materials can vary from product to product.  Breakthrough times are obtained under conditions of continuous contact, generally at room temperature.  Evaluate resistance under conditions of use and maintain clothing carefully.

Saranex™ is a trademark of the Dow Chemical Company
Barricade® is a registered trademark of DuPont
Responder® is a registered trademark of Kappler

Reference: Forsberg, K., et al. Quick selection guide to chemical protective clothing. 3rd edition. Van Nostrand Reinhold, 1997.

Safety Signs

From a transportation perspective, sulphur dioxide is classified as a poisonous gas and an inhalation hazard.  Any or all of the following signs maybe displayed in the presence of sulphur dioxide.