# NIOSH Pocket Guide to Chemical Hazards
Perchloromethyl mercaptan | CAS 594-42-3
Cl3CSCl | RTECS PB0370000
Synonyms & Trade Names PCM, PMM, Trichloromethane sulfenyl chloride, Trichloromethyl sulfur chloride | DOT ID & Guide 1670 157
Exposure Limits | NIOSH REL: TWA 0.1 ppm (0.8 mg/m3)
OSHA PEL: TWA 0.1 ppm (0.8 mg/m3)
IDLH 10 ppm | Conversion 1 ppm = 7.60 mg/m3
Physical Description Pale-yellow, oily liquid with an unbearable, acrid odor.
MW: 185.9 | BP: 297°F (Decomposes) | FRZ: ? | Sol: Insoluble
VP: 3 mmHg | IP: ? |  | Sp.Gr: 1.69
Fl.P: NA | UEL: NA | LEL: NA |
Noncombustible Liquid, but will support combustion.
Incompatibilities & Reactivities Alkalis, amines, hot iron, water [Note: Corrosive to most metals. Forms HCl, sulfur & CO2 on contact with water.]
Measurement Methods None available
Personal Protection & Sanitation Skin: Prevent skin contact Eyes: Prevent eye contact Wash skin: When contaminated Remove: When wet or contaminated Change: No recommendation | First Aid (See procedures) Eye: Irrigate immediately Skin: Soap wash immediately Breathing: Respiratory support Swallow: Medical attention immediately
Respirator Recommendations NIOSH/OSHA Up to 1 ppm: (APF = 10) Any chemical cartridge respirator with organic vapor cartridge(s)*/(APF = 10) Any supplied-air respirator* Up to 2.5 ppm: (APF = 25) Any supplied-air respirator operated in a continuous-flow mode*/(APF = 25) Any powered, air-purifying respirator with organic vapor cartridge(s)* Up to 5 ppm: (APF = 50) Any chemical cartridge respirator with a full facepiece and organic vapor cartridge(s)/(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/(APF = 50) Any powered, air-purifying respirator with a tight-fitting facepiece and organic vapor cartridge(s)*/(APF = 50) Any supplied-air respirator that has a tight-fitting facepiece and is operated in a continuous-flow mode*/(APF = 50) Any self-contained breathing apparatus with a full facepiece/(APF = 50) Any supplied-air respirator with a full facepiece Up to 10 ppm: (APF = 2000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode Emergency or planned entry into unknown concentrations or IDLH conditions: (APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode/(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus Escape: (APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted organic vapor canister/Any appropriate escape-type, self-contained breathing apparatus
Exposure Routes inhalation, skin absorption, ingestion, skin and/or eye contact
Symptoms Irritation eyes, skin, nose, throat; lacrimation (discharge of tears); cough, dyspnea (breathing difficulty), deep breathing pain, coarse rales; vomiting; pallor, tachycardia; acidosis; anuria; liver, kidney damage
Target Organs Eyes, skin, respiratory system, liver, kidneys
See also: INTRODUCTION