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Chemical Sampling Information (CSI)
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General Description

Synonyms: Anhydrous hydrogen chloride; Aqueous hydrogen chloride; Hydrochloric acid, Muriatic acid; HCl

OSHA IMIS Code Number: 1430

Chemical Abstracts Service (CAS) Registry Number: 7647-01-0

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: MW4025000

Department of Transportation Regulation Number (49 CFR 172.101) and 2012 Emergency Response Guidebook [4 MB PDF, 392 pages]: 1050 125 (anhydrous); 1789 157 (solution)

NIOSH Pocket Guide to Chemical Hazards - Hydrogen Chloride: Physical description, chemical properties, potentially hazardous incompatibilities, and more

U.S. Environmental Protection Agency (EPA) Hazard Summary - Hydrogen Chloride: Uses, sources and potential exposure, acute and chronic health hazard information, and more

Exposure Limits and Health Effects

Exposure Limit

Limit Values

HE Codes

Health Factors and Target Organs

OSHA Permissible Exposure Limit (PEL) - General Industry
See 29 CFR 1910.1000 Table Z-1

5 ppm
(7 mg/m3) Ceiling

HE3

Corrosion, yellowing, and breaking of teeth

HE4

Skin and eye burns, blindness, frostbite (on contact with liquid)

HE11

Respiratory irritation, airway obstruction, cough, choking, hoarseness, pulmonary edema

HE14

Marked eye, nose, throat, and skin irritation and ulceration; dermatitis

OSHA PEL - Construction Industry
See 29 CFR 1926.55 Appendix A

5 ppm
(7 mg/m3) Ceiling

HE3

Corrosion, yellowing, and breaking of teeth

HE4

Skin and eye burns, blindness, frostbite (on contact with liquid)

HE11

Respiratory irritation, airway obstruction, cough, choking, hoarseness, pulmonary edema

HE14

Marked eye, nose, throat, and skin irritation and ulceration; dermatitis

OSHA PEL - Shipyard Employment
See 29 CFR 1915.1000 Table Z-Shipyards

5 ppm
(7 mg/m3) Ceiling

HE3

Corrosion, yellowing, and breaking of teeth

HE4

Skin and eye burns, blindness, frostbite (on contact with liquid)

HE11

Respiratory irritation, airway obstruction, cough, choking, hoarseness, pulmonary edema

HE14

Marked eye, nose, throat, and skin irritation and ulceration; dermatitis

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL)

5 ppm
(7 mg/m3) Ceiling

HE11

Respiratory irritation, airway obstruction, cough, choking, hoarseness, pulmonary edema

HE14

Marked eye, nose, throat, and skin irritation and ulceration; dermatitis

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2003)

2 ppm
(3 mg/m3) Ceiling

A4

HE4

Acute skin and eye burns, blindness, frostbite (on contact with liquid)

HE11

Respiratory irritation, airway obstruction, cough, choking, hoarseness, pulmonary edema

HE14

Marked eye, nose, throat, and skin irritation and ulceration; dermatitis

CAL/OSHA PEL

5 ppm
(7 mg/m3) Ceiling

 

 

National Toxicology Program (NTP) carcinogenic classification: Not listed

International Agency for Research on Cancer (IARC) carcinogenic classification: Group 3 [2 MB PDF, 23 pages] (not classifiable as to its carcinogenicity to humans)

EPA carcinogenic classification: Not listed

EPA Inhalation Reference Concentration (RfC): 2x10-2 mg/m3

Agency for Toxic Substances and Disease Registry (ATSDR) Inhalation Minimal Risk Level (MRL): Not established

NIOSH Immediately Dangerous to Life or Health (IDLH) concentration: 50 ppm

Notes on Other Potential Health Effects

  1. Hydrogen chloride has not been found to be combustible (NIOSH/IPCS 2000).
  2. Mixing hydrochloric acid with a sodium hypochlorite solution (bleach) may lead to the production of chlorine gas and severe respiratory effects (Gorguner et al. 2004).
  3. Breathing in hydrochloric acid aerosols, even for healthy individuals, can elicit bronchial spasms and decreased lung function (Micric and Plavec 2004).
  4. Recent reports indicate that inhalation of hydrogen chloride particles may lead to fibrosis of the bronchioles and interstitial tissue in certain cases (Serrano et al. 2006).
  5. IARC classified mists from strong inorganic acids as Group 1, Known to be Carcinogenic to Humans. This assessment included studies in people exposed to mixtures containing hydrochloric acid.
  6. Short term high exposures to irritants may cause reactive airway dysfunction syndrome, a persistent condition resembling asthma but without an immunological trigger. (Brooks 1985)
  7. The EPA reference concentration was based on the observation of Hyperplasia of nasal mucosa, larynx and trachea in a chronic inhalation study in rats. (EPA 1995)

Date Last Revised: 11/16/2012

Literature Basis:

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Hydrogen Chloride. 2003.
  • Albert, R.E., A.R. Sellakumar, S. Laskin, M. Kuschner, N. Nelson and C.A. Snyder. 1982. Gaseous formaldehyde and hydrogen chloride induction of nasal cancer in rats. J. Natl. Cancer Inst. 68(4): 597-603.
  • Brooks, S M; M A Weiss; I L Bernstein, Reactive airways dysfunction syndrome (RADS). Persistent asthma syndrome after high level irritant exposures  CHEST.;88(3):376-384 1985.
  • EPA IRIS Hydrochloric Acid, 1985
  • Gorguner, M., Aslan, S., Inandi, T. and Cakir, Z.: Reactive airways dysfunction syndrome in housewives due to a bleach-hydrochloric acid mixture. Inhal. Toxicol. 16(2): 87-91, 2004.
  • IARC Monographs Mists from Strong Inorganic Acids, 2011 [428 KB PDF, 10 pages].
  • Micric, M. and Plavec, D.: Risk of acute bronchospasm and bronchial hyperreactivity from inhaled acid aerosol in healthy subjects: randomized, double-blind controlled trial. Croat. Med. J. 45(6): 709-714, 2004.
  • NIOSH: Occupational Health Guideline for Hydrogen Chloride. September 1978.
  • NIOSH/IPCS: International Chemical Safety Cards - Hydrogen chloride. October 4, 2000.
  • Serrano, M. et al.: Airway-centered interstitial fibrosis related to exposure to fumes from cleaning products. Arch Bronconeumol. 42(10): 557-559, 2006.
  • Sellakumar, A.R., C.A. Snyder, J.J. Solomon and R.E. Albert. 1985. Carcinogenicity for formaldehyde and hydrogen chloride in rats. Toxicol. Appl. Pharmacol. 81: 401-406, 1985

Monitoring Methods used by OSHA

Laboratory Sampling/Analytical Method:

  • sampling media: specially cleaned silica gel tube (400/200 mg sections with glass fiber filter) (Supelco, ORBO-53; SKC, 226-10-03; or equivalent)
    minimum volume: 2.5 liters
    maximum volume: 7.5 Liters (Ceiling)
    maximum flow rate: 0.5 L/min
    current analytical method: Ion Chromatography; IC
    method reference: OSHA Manual of Analytical Methods (OSHA ID-174SG)
    method classification: Partially Validated
    note: Submit as a separate sample, however, hydrogen bromide can be analyzed from the same sample. The sample is analyzed for chloride (or bromide, if requested) and the result reported as the acid. Make sure that the glass fiber filter plug is firmly in contact with the silica gel before and after sampling. Report the presence of chloride (or bromide) salts to the analytical laboratory.

On-Site Sampling/Analytical Methods:

  • device: Detector Tube
    manufacturer: Gastec
    model/type: 14L
    sampling information: 0.5 to 5 strokes
    upper measurement limit: 76 ppm
    detection limit: 0.05 ppm
    overall uncertainty: 16.4% for 1 to 5 ppm, 8.2 % for 5 to 20 ppm
    method reference: on-site air secondary (SEI Certified)
  • device: Detector Tube
    manufacturer: Matheson-Kitagawa
    model/type: 8014-173SB
    sampling information: follow manufacturer's instructions
    upper measurement limit: 40 ppm
    detection limit: 0.4 ppm
    overall uncertainty: unknown
    method reference: on-site air secondary (SEI Certified)

Wipe sampling:

    media for liquid solutions: Whatman smear tab
    analytical solvent: Deionized Water

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