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Chemical Sampling Information (CSI)
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General Description

Synonyms: White phosphoric acid; Orthophosphoric acid; Metaphosphoric acid

OSHA IMIS Code Number: 2085

Chemical Abstracts Service (CAS) Registry Number: 7664-38-2

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: TB6300000

Department of Transportation Regulation Number (49 CFR 172.101) and 2012 Emergency Response Guidebook [4 MB PDF, 392 pages]: 1805 154 (liquid or solution); 3454 154 (solid)

NIOSH Pocket Guide to Chemical Hazards - Phosphoric Acid: Physical description, chemical properties, potentially hazardous incompatibilities, 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

1 mg/m3 TWA

HE14

Throat irritation

OSHA PEL - Construction Industry
See 29 CFR 1926.55 Appendix A

1 mg/m3 TWA

HE14

Throat irritation

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

1 mg/m3 TWA

HE14

Throat irritation

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

1 mg/m3 TWA

3 mg/m3 STEL

HE4

Eye and skin burns

HE14

Eye, nose, skin, and throat irritation

American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) (2001)

1 mg/m3 TWA

3 mg/m3 STEL

HE14

Eye, skin, and respiratory irritation

CAL/OSHA PELs

1 mg/m3 TWA

3 mg/m3 STEL

HE14

Eye, skin, and respiratory irritation

National Toxicology Program (NTP) carcinogenic classification: Not listed

International Agency for Research on Cancer (IARC) carcinogenic classification: Not listed

U.S. Environmental Protection Agency (EPA) carcinogenic classification: Not listed

EPA Inhalation Reference Concentration (RfC): 1x10-2mg/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: 1,000 mg/m3

Notes on Other Potential Health Effects and Hazards

  1. Exposure to phosphoric acid fumes in a battery factory was found to be significantly associated with dental erosion and deteriorated dental health in the workers (Amin et al. 2001).

Date Last Revised: 9/6/2012

Literature Basis

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Phosphoric Acid. 2001.
  • Amin, W.M., Al-Omoush, S.A. and Hattab, F.N.: Oral health status of workers exposed to acid fumes in phosphate and battery industries in Jordan. Int. Dent. J. 51(3): 169-174, 2001.
  • NIOSH: Occupational Health Guideline for Phosphoric Acid. September 1978.
  • NIOSH/IPCS: International Chemical Safety Cards - Phosphoric Acid. March 10, 2000.
Monitoring Methods used by OSHA

Laboratory Sampling/Analytical Method:

  • sampling media: Mixed Cellulose Ester Filter (MCEF) 0.8 microns
    maximum volume: 960 Liters
    maximum flow rate: 2.0 L/min (TWA)
    maximum volume: 30 Liters
    maximum flow rate: 2.0 L/min (STEL)
    current analytical method: Ion Chromatography; IC
    method reference: OSHA Analytical Method (OSHA ID-111)
    method classification: Partially Validated
    note: If the filter is not overloaded, samples may be collected up to an 8-hour period. Within 1 hour after sampling, transfer the filter to a clean screw cap vial. Phosphoric and sulfuric acid may be submitted on the same filter; otherwise, submit as a separate filter.

  • sampling media: Treated Silica Gel Tube (Supelco ORBO-53, SKC, 226-10-03 or equivalent)
    maximum volume: 96 Liters   
    maximum flow rate: 0.2 L/min (TWA)
    maximum volume: 7.5 Liters   
    maximum flow rate: 0.5 L/min (STEL)
    current analytical method: Ion Chromatography; IC (See note)
    method reference: OSHA Analytical Method (OSHA ID-165SG)
    method classification: Partially Validated
    note: Phosphoric, Nitric, Hydrochloric, Hydrobromic and Sulfuric Acids may be submitted on the same tube. Sampling and analysis for this method are for combinations that include gaseous acids (Nitric, Hydrochloric, Hydrobromic) with Phosphoric and Sulfuric Acid mists.

Wipe Sampling Method:

  • sampling media: Whatman smear tab
    analytical solvent: Deionized water

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