Hydrogen Chloride - HCl  
 
Hazard:                      Flammable - Will explode, LEL 12.5% 
Classification:                    Health - Extremely toxic 
Oxidizing Agent 
Synonyms:                 Anhydrous Hydrochloric Acid, Chlorohydric Acid, Hydrochloride, Spirits of Salt, Muriatic Acid 
Exposure limits:       (OSHA) PEL\TWA: 5 ppm 
                                    (ACGIH) STEL: N/A
                                    (OSHA) IDLH: 50 ppm   
Industries:                  Vinyl and Cotton Production, Semi-Conductor Crystals Etching, Petroleum and Gas Wells, Steel Manufacturing 
   
Hydrogen Chloride is a colorless to slight yellow corrosive gas with a pungent irritating odor. Although not considered a combustible gas, it may react or form combustible compounds when contact is made with alcohol and hydrogen cyanide or with aluminum-titanium alloys. Dissolving Hydrogen Chloride in water will yield a strong highly corrosive acid. It is for this reason that HCl is a strong irritant to the eyes, nose, and upper respiratory tract. Levels of 35 ppm can cause irritation to the throat even after a very short period of time. 
   
Effects of Various HCl Levels  
 Hydrogen Chloride Level in PPM             Resulting Conditions on Humans 
.25                                                  Odor threshold 
5                                                     Permissible Exposure Limit (PEL) 
35                                                  Irritation to the eyes, nose, throat even after a short period of time. 
50                                                 Immediately Dangerous to Life and Health (IDLH) 
1,300-2,000                                 Death in 2-3 minutes