THIONYL CHLORIDE

Diamond	Hazard	Value	Description
0 4 2 W	Health	4	Can be lethal.
	Flammability	0	Will not burn under typical fire conditions.
	Instability	2	Readily undergoes violent chemical changes at elevated temperatures and pressures.
	Special	W	Reacts violently or explosively with water.

A colorless to yellow fuming liquid with a suffocating pungent odor. Boiling point 79°C. A lachrymator. Highly corrosive and toxic. Long-term inhalation of low concentrations or short-term inhalation of high concentrations has adverse health effects.

• Water-Reactive
• Air-Reactive

Emits dense corrosive fumes in moist air. Violently reacts with water to liberate hydrochloric acid and sulfur dioxide [NFPA 10th ed. 1991].

Thionyl chloride reacts vigorously with water to generate gaseous HCl and SO2. 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 Sulfur Dioxide gas will be created in 0.25 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 ERG Guide 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, 2024)

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

CORROSIVE and/or TOXIC; inhalation, ingestion or contact (skin, eyes) with vapors, dusts or substance may cause severe injury, burns or death. Fire will produce irritating, corrosive and/or toxic gases. Reaction with water may generate much heat that will increase the concentration of fumes in the air. Contact with molten substance may cause severe burns to skin and eyes. Runoff from fire control or dilution water may cause environmental contamination. (ERG, 2024)

THIONYL CHLORIDE reacts, potentially explosively, with dimethyl sulfoxide or dimethylformamide containing traces of iron or zinc [Spitulnik, M. J., Chem. Eng. News, 1977, 55(31), p. 31]. Undergoes violent reactions with bases (ammonia, sodium hydroxide, potassium hydroxide, amines), alkali metals (sodium, potassium), esters (ethyl acetate), toluene mixed with ethanol / water [Bretherick, 5th ed., 1995, p. 1325]. Has an expansion ratio from gas to liquid of nearly 1000:1. Hence may cause an explosion if heated while contained [MCA Case History No. 1808]. May react vigorously or explosively if mixed with diisopropyl ether or other ethers in the presence of trace amounts of metal salts [J. Haz. Mat., 1981, 4, 291]. Perchloric acid ignites on contact with sulfinyl chloride. (Bailar, 1973, Vol. 2, 1442). SOCl2 reacts with esters, such as ethyl acetate, forming toxic SO2 gas and water soluble/toxic acyl chlorides, catalyzed by Fe or Zn (Spagnuolo, C.J. et al. 1992. Chemical and Engineering News 70(22):2.).

• Acyl Halides, Sulfonyl Halides, and Chloroformates

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 ERG Guide 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 1836 datasheet.

FIRE: If tank, rail tank car or highway tank 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, 2024)

Excerpt from ERG Guide 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, RAIL TANK CARS OR HIGHWAY TANKS: 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 in direct contact with flames. (ERG, 2024)

Excerpt from ERG Guide 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, 2024)

Excerpt from NIOSH Pocket Guide for Thionyl chloride:

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, 2024)

Normalized Breakthrough Times (in Minutes)

Chemical	CAS Number	State	QS	QC	SL	C3	TF	TP	RC	TK	RF
Thionyl chloride	7719-09-7	Liquid				15	21	21	35	90	35

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Excerpt from NIOSH Pocket Guide for Thionyl chloride:

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, 2024)

• SULFINYL CHLORIDE
• SULFINYL DICHLORIDE
• SULFUR CHLORIDE OXIDE
• SULFUR CHLORIDE OXIDE (CL2SO)
• SULFUR CHLORIDE OXIDE (SCL2O)
• SULFUR OXYCHLORIDE
• SULFUR OXYCHLORIDE (SOCL2)
• SULFUROUS DICHLORIDE
• SULFUROUS OXYCHLORIDE
• THIONYL CHLORIDE
• THIONYL CHLORIDE (SOCL2)
• THIONYL DICHLORIDE