Ikmanda RoswatiPh.D.Indonesia
Ultrafast Laser Physics and Material InteractionsPublished
Dec 24, 2025
Hydrogen Chloride (HCl)
Chemical Properties
Chemical Identity
CAS Number
7647-01-0
Formula
HCl
Molecular Weight
36.46 g/mol
Exposure Limits Comparison
NIOSH REL
5 ppm
Health Effects
Severe Respiratory Irritation
Yes
Corrosive To Tissue
Yes
Pulmonary Edema
Yes
Tooth Erosion
Yes
Hydrogen Chloride (HCl) safety information
Comprehensive safety and handling requirements
Detection Monitoring
- Electrochemical
- Infrared
- Colorimetric
- Dräger HCl 0.2/a
- Gastec 14L
- Kitagawa 183
| Sensor Types | ||||||||||
| Detection Range | 0-50 ppm typical | |||||||||
| Alarm Setpoints |
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| Colorimetric Tubes | ||||||||||
| Analytical Methods |
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| Odor Threshold | 0.8-5 ppm - provides adequate warning but close to toxic levels |
Environmental Impact
| Aquatic Toxicity | Toxic to aquatic life. LC50 (fish, 96h): 100-300 mg/L HCl solution. Acidifies water. | ||||
| Biodegradability | Not biodegradable. Dissolves in water forming hydrochloric acid. | ||||
| Bioaccumulation | Does not bioaccumulate. | ||||
| Soil Mobility | High mobility as gas. Deposits as chloride salts. Acidifies soil. | ||||
| Atmospheric Fate | Rapidly dissolves in atmospheric moisture. Forms hydrochloric acid droplets. Washed out by rain. | ||||
| Ozone Depletion | false | ||||
| Reportable Releases |
|
Ppe Requirements
| Respiratory | SCBA or supplied-air respirator for >5 ppm or unknown concentrations. Air-purifying with acid gas cartridge acceptable for ≤5 ppm with escape provisions. |
| Eye Protection | Chemical safety goggles, full face shield mandatory. Extremely corrosive to eyes. |
| Skin Protection | Neoprene or butyl rubber gloves, chemical-resistant suit. HCl is highly corrosive to skin. |
Reactivity
- Metals (Al, Zn, Fe - generates H2)
- Strong bases
- Strong oxidizers
- Alcohols
- Amines
- Aldehydes
- Metal carbides
- Hydrogen chloride gas
- Chlorine (if heated with oxidizers)
- Moisture
- Heat
- Incompatible materials
- Metals
| Stability | Stable as dry gas. Forms corrosive hydrochloric acid with moisture. |
| Polymerization | Will not polymerize |
| Incompatible Materials | |
| Hazardous Decomposition | |
| Conditions To Avoid | |
| Reactivity Hazard | Reacts violently with metals producing flammable hydrogen gas. Reacts exothermically with bases. Forms corrosive mist in humid air. |
Regulatory Classification
- Acute toxicity (inhalation)
- Skin corrosion
- Serious eye damage
| Un Number | UN1050 (anhydrous), UN1789 (solution) | ||||||
| Dot Hazard Class | 2.3 (Toxic gas), 8 (Corrosive) | ||||||
| Dot Label | Poison Gas, Corrosive | ||||||
| Nfpa Codes |
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| Epa Hazard Categories | |||||||
| Sara Title Iii | true | ||||||
| Cercla Rq | 5000 pounds (2270 kg) |
Storage Requirements
- Metals (generates hydrogen)
- Bases
- Oxidizers
- Alcohols
- Amines
- Aldehydes
- Metal carbides
| Temperature Range | Store cylinders <52°C. Keep away from heat. |
| Ventilation | Outdoor storage preferred. Indoor: mechanical ventilation with acid-resistant ductwork. HCl gas detection required. |
| Incompatibilities | |
| Container Material | Steel cylinders for compressed gas. Glass, PVC, PVDF, or PTFE for liquid. |
| Segregation | Separate from bases, oxidizers, and metals. Corrosive storage area. |
| Quantity Limits | Per fire code. Minimize indoor storage of cylinders. |
| Special Requirements | Cylinder restraints mandatory. Leak detection system required. Post "CORROSIVE GAS" signs. Emergency eyewash/shower within 25 feet. Store in cool, dry area. Protect from physical damage. |
Produced From Contaminants
Produced From Materials
Exposure Limits
Regulatory exposure thresholds and safe concentration levels
- Osha Pel Mg M3
- 7
- Niosh Rel Ppm
- 5
- Niosh Rel Mg M3
- 7
- Acgih Tlv Mg M3
- 2
- Workplace Exposure
- Osha Peltwa_8hr: nullstel_15min: nullceiling: 5 ppm (7 mg/m³)Niosh Reltwa_8hr: nullstel_15min: nullceiling: 5 ppm (7 mg/m³)idlh: 50 ppmAcgih Tlvtwa_8hr: nullstel_15min: nullceiling: 2 ppmBiological Exposure Indices
Physical Properties
Physical characteristics and state information
- Boiling Point
- -85.05°C (-121°F)
- Melting Point
- -114.17°C (-173.5°F)
- Vapor Pressure
- >760 mmHg @ 20°C (gas)
- Vapor Density
- 1.27 (Air=1)
- Specific Gravity
- 1.19 (liquid @ -26°C)
- Flash Point
- Not applicable (non-flammable)
- Autoignition Temp
- Not applicable
- Explosive Limits
- Not applicable
- Appearance
- Colorless gas, colorless to light yellow liquid (anhydrous)
- Odor
- Pungent, irritating odor @ 0.8-5 ppm
Reactivity
Chemical reactivity and compatibility with other substances
- Stability
- Stable as dry gas. Forms corrosive hydrochloric acid with moisture.
- Polymerization
- Will not polymerize
- Incompatible Materials
- Metals (Al, Zn, Fe - generates H2)
- Strong bases
- Strong oxidizers
- Alcohols
- Amines
- Aldehydes
- Metal carbides
- Hazardous Decomposition
- Hydrogen chloride gas
- Chlorine (if heated with oxidizers)
- Conditions To Avoid
- Moisture
- Heat
- Incompatible materials
- Metals
- Reactivity Hazard
- Reacts violently with metals producing flammable hydrogen gas. Reacts exothermically with bases. Forms corrosive mist in humid air.
Synonyms & Identifiers
Alternative names and chemical identifiers (CAS numbers)
- Synonyms
- Hydrochloric acid gas
- Muriatic acid gas
- Chlorohydric acid
- Anhydrous hydrogen chloride
- Common Trade Names
- Other Identifiers
- Rtecs NumberMW4025000Ec Number231-595-7Pubchem Cid313
