Sulfur Fires

Fire Fighting

Avoid the inhalation of sulfur dioxide from burning sulfur. Sulfur dioxide (SO2) is a toxic gas.

Approved Code of Practice for the Prevention of Sulphur Fires and Explosions

The following information was taken from: Flaked Sulfur SDS


Flashpoint:  405°F - (207.2°C)

Explosive Limits of Dust in Air:  LEL 35 g/m3 - UEL 1400 g/m3

Auto-ignition Temperature:  478-511°F - (248-266°C)

Burning Sulfur decomposes into TOXIC sulfur oxide gasses such as:

Sulfur dioxide (SO2) and Hydrogen sulfide (H2S)

Primary Hazard

Sulfur dust suspended in air ignites easily, and can cause an explosion in confined areas. May be ignited by friction, static electricity, heat, sparks, or flames. Toxic gases will form upon combustion. Bulk/solid forms burn only at moderate rate, whereas dust burns with explosive violence.


Wear full-faced, self-contained breathing apparatus and full protective clothing. Use a water fog to extinguish fire. Do not use solid streams of water; which could create sulfur dust clouds and cause an explosion or move burning sulfur to adjacent areas. Fire will rekindle until mass is cooled below 310 oF (154oC). Cool surrounding areas with water fog to prevent re-igniting. Cool containers, tank cars, or trailer loads with flooding quantities of water until well after fire is out. Evacuate nonessential personnel from the fire area. If large fire, evacuate people downwind from fire. Isolate for ½ mile in all directions, consider evacuation for ½ mile in all directions. Prevent human exposure to smoke, fumes, or products of combustion (sulfur oxide gases). Firemen exposed to contaminated smoke should be immediately relieved and checked for symptoms of exposure to toxic gasses. Seek medical attention immediately! . This should not be mistaken for heat exhaustion or smoke inhalation. These are extremely irritating to the respiratory tract and may cause breathing difficulty and pulmonary edema. Symptoms may be delayed several hours or longer depending upon exposure.

Hazard Rating Guide

0 = Least, 1 = Slight, 2 = Moderate, 3 = High, 4 = Extreme

  • Acute Health = 1
  • Fire = 1
  • Reactivity = 0
  • Conact = 1

Additional Information

Incipient fires in sulfur storage piles can be frequently smothered by gently shoveling more sulfur, sand, or fine earth on them to exclude all air. For larger fires, water applied as a fine mist is the most useful agent. High pressure water sprays disperse the dust into the air and should not be used. Coarser water sprays are permissible on deposits containing only a small proportion of extreme sulfur fines.

Steam or inert gases are excellent extinguishers for use in containers that can be closed tightly. Care should be taken that the sulfur dust is not scattered into the air. If a container is closed tightly and the volume of oxygen enclosed is not too large, a fire will be put out by the sulfur dioxide formed. Sulfur dioxide is a toxic gas.

Firefighters handling larger fires should be equipped with breathing apparatus with a self contained air supply. Gas masks approved for acid gases would not provide adequate protection in a serious sulfur fire. In all cases, it should be certain that the fire is fully extinguished before disturbing the dust and that the sulfur has cooled sufficiently so that it will not re-ignite.

Emergency Response Guide 133

EMERGENCY ASSISTANCE: CHEMTREC 1-800-424-9300 (24 Hours)

Emergency only: (229) 563-2529

Corporate Office, Valdosta Georgia USA: phone (229) 244-0000 or (800) 234-7094

Bainbridge Georgia USA Manufacturing Plant: phone (229) 246-4552

Acton Ontario Canada Manufacturing Plant: phone (519) 853-0120

Freeport Texas USA Manufacturing Plant: phone (800) 234-7094 or (979) 233-3555

Mt. Pleasant Texas USA Manufacturing Plant: phone (800) 828-7857 or (903) 577-5500