SULFUR MONOCHLORIDE

Diamond	Hazard	Value	Description
1 4 2 W	Health	4	Can be lethal.
	Flammability	1	Must be preheated before ignition can occur.
	Instability	2	Readily undergoes violent chemical changes at elevated temperatures and pressures.
	Special	W	Reacts violently or explosively with water.

A yellow-red, oily, fuming liquid with a sharp odor. Contact or ingestion causes irritation or chemical burns to skin, eyes, and mucous membranes. Also poisonous by inhalation of vapors.

• Water-Reactive
• Air-Reactive

Fumes in air. Decomposed by water yields hydrogen sulfide, hydrochloric acid, sulfur dioxide, sulfite, hydrogen sulfide, and thiosulfate [Merck 11th ed. 1989]. Very corrosive in the presence of water; reacts violently with water and strong oxidants to form toxic and corrosive gas; on contact with air, it gives off HCl. [Handling Chemicals Safely 1980 p.874].

Based on a scenario where the chemical is spilled into an excess of water (at least 5 fold excess of water), half of the maximum theoretical yield of Hydrogen Chloride gas will be created in 1.8 minutes. Experimental details are in the following: "Development of the Table of Initial Isolation and Protective Distances for the 2008 Emergency Response Guidebook", ANL/DIS-09-2, D.F. Brown, H.M. Hartmann, W.A. Freeman, and W.D. Haney, Argonne National Laboratory, Argonne, Illinois, June 2009.

Excerpt from 137 [Substances - Water-Reactive - Corrosive]:

EXCEPT FOR ACETIC ANHYDRIDE (UN1715), THAT IS FLAMMABLE, some of these materials may burn, but none ignite readily. May ignite combustibles (wood, paper, oil, clothing, etc.). Substance will react with water (some violently), releasing corrosive and/or toxic gases and runoff. Flammable/toxic gases may accumulate in confined areas (basement, tanks, hopper/tank cars, etc.). Contact with metals may evolve flammable hydrogen gas. Containers may explode when heated or if contaminated with water. Substance may be transported in a molten form. (ERG, 2020)

Vapors irritate eyes and respiratory system; pulmonary edema may result. Liquid burns and damages eyes. Unless removed at once, it burns the skin. Ingestion causes severe damage to mouth and stomach. (USCG, 1999)

SULFUR MONOCHLORIDE poses a fire hazard in contact with organic matter. Can react violently with oxidizing agents to form toxic gases. Reacts violently with sodium peroxide, chromyl chloride, phosphorus trioxide. Emits highly toxic fumes of sulfur oxides and chlorides when heated to decomposition [Lewis, 3rd ed., 1993, p. 1196]. Reacts exothermically with tin, antimony, antimony sulfide, arsenic sulfide, mercury oxide. A mixture with potassium is shock-sensitive and explodes violently on heating [Mellor, 1947, 10, p.642]. Reacts particularly violently with dimethyl sulfoxide [Buckley, A., J. Chem. Ed., 1965, 42, p. 674].

• Halogenating Agents

Use caution: Liquids with this reactive group classification have been known to react with the absorbents listed below.

• Cellulose-Based Absorbents
• Mineral-Based & Clay-Based Absorbents
• Dirt/Earth

Excerpt from 137 [Substances - Water-Reactive - Corrosive]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

SPILL: See ERG Table 1 - Initial Isolation and Protective Action Distances on the UN/NA 1828 datasheet.

FIRE: If tank, rail car or tank truck is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2020)

Excerpt from 137 [Substances - Water-Reactive - Corrosive]:

When material is not involved in fire, do not use water on material itself.

SMALL FIRE: Dry chemical or CO2. If it can be done safely, move undamaged containers away from the area around the fire.

LARGE FIRE: Flood fire area with large quantities of water, while knocking down vapors with water fog. If insufficient water supply, responders should withdraw.

FIRE INVOLVING TANKS OR CAR/TRAILER LOADS: Cool containers with flooding quantities of water until well after fire is out. Do not get water inside containers. Withdraw immediately in case of rising sound from venting safety devices or discoloration of tank. ALWAYS stay away from tanks engulfed in fire. (ERG, 2020)

Excerpt from 137 [Substances - Water-Reactive - Corrosive]:

Do not touch damaged containers or spilled material unless wearing appropriate protective clothing. Stop leak if you can do it without risk. Use water spray to reduce vapors; do not put water directly on leak, spill area or inside container. Keep combustibles (wood, paper, oil, etc.) away from spilled material.

SMALL SPILL: Cover with DRY earth, DRY sand or other non-combustible material followed with plastic sheet to minimize spreading or contact with rain. Use clean, non-sparking tools to collect material and place it into loosely covered plastic containers for later disposal. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2020)

Excerpt from NIOSH Pocket Guide for Sulfur monochloride:

Skin: PREVENT SKIN CONTACT - Wear appropriate personal protective clothing to prevent skin contact.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: WHEN CONTAMINATED - The worker should immediately wash the skin when it becomes contaminated.

Remove: WHEN WET OR CONTAMINATED - Work clothing that becomes wet or significantly contaminated should be removed and replaced.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift.

Provide:
• EYEWASH - Eyewash fountains should be provided in areas where there is any possibility that workers could be exposed to the substances; this is irrespective of the recommendation involving the wearing of eye protection.
• QUICK DRENCH - Facilities for quickly drenching the body should be provided within the immediate work area for emergency use where there is a possibility of exposure. [Note: It is intended that these facilities provide a sufficient quantity or flow of water to quickly remove the substance from any body areas likely to be exposed. The actual determination of what constitutes an adequate quick drench facility depends on the specific circumstances. In certain instances, a deluge shower should be readily available, whereas in others, the availability of water from a sink or hose could be considered adequate.] (NIOSH, 2023)

Normalized Breakthrough Times (in Minutes)

Chemical	CAS Number	State	QS	QC	SL	C3	TF	TP	RC	TK	RF
Disulphur dichloride	10025-67-9	Liquid							>480	>480	>480
Sulfur monochloride	10025-67-9	Liquid							>480	>480	>480

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(DuPont, 2023)

Excerpt from NIOSH Pocket Guide for Sulfur monochloride:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Skin: WATER FLUSH IMMEDIATELY - If this chemical contacts the skin, immediately flush the contaminated skin with water. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water. Get medical attention promptly.

Breathing: RESPIRATORY SUPPORT - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. If breathing has stopped, perform artificial respiration. Keep the affected person warm and at rest. Get medical attention as soon as possible.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2023)

• CHLOROSULFANE
• DICHLORODISULFANE
• DISULFUR DICHLORIDE
• SULFUR CHLORIDE
• SULFUR CHLORIDES
• SULFUR MONOCHLORIDE
• SULFUR MONOCHLORIDE (S2CL2)
• SULFUR SUBCHLORIDE
• SULPHUR CHLORIDE (S2CL2)
• SULPHUR CHLORIDES
• THIOSULFUROUS DICHLORIDE