CALCIUM HYDROXIDE†

Chemical Identification
Chemical Identification
CAS # 1305-62-0
Formula

Ca(OH)₂

Synonyms

calcium hydrate; caustic lime; hydrated lime; slaked lime

Physical Properties
Physical Properties
Physical description White, odorless powder.
Boiling point decomposes Molecular weight 74.1
Freezing point/melting point 1076°F (decomposes) (loses H₂O) Vapor pressure 0 mmHg (approx)
Flash point Vapor density
Specific gravity 2.24 Ionization potential
Lower explosive limit (LEL) Upper explosive limit (UEL)
NFPA health rating NFPA fire rating
NFPA reactivity rating NFPA special instruction
Vapor hazard ratio (VHR)
Historical exceedance percentage
Target organs
Monitoring Methods Used by OSHA
Monitoring Methods Used by OSHA
Analyte code (IMIS no.) 0515 (total); request using analyte code 9135 C330 (resp); request using analyte code 9130
Sampling group
Sampler/Sampling media Tared low-ash 37 mm PVC filter, 5 microns [SLTC108] Tared low-ash 37 mm PVC filter, 5 microns, preceded by 10 mm nylon Dorr-Oliver cyclone for respirable samples. [SLTC108]
Sampling time*

240-480 min

240-480 min

Sampling volume (TWA)*

960 L

816 L

Sampling flow rate (TWA)*

2 L/min

1.7 L/min ±5%

Sampling volume (STEL/Peak/C)*
Sampling flow rate (STEL/Peak/C)*
Analytical method instruments Gravimetric Gravimetric
Method reference OSHA PV2121 (partially validated) OSHA PV2121 (partially validated)
Notes

Samples collected for this compound are first analyzed gravimetrically. If the gravimetric result of a sample yields a concentration below the permissible exposure limit (PEL), the SLTC will report the calculated air concentration for the requested compound solely from the gravimetric result, qualified as less than or equal to the gravimetric result; no further work on the sample will be performed.

If the gravimetric result indicates an air concentration greater than the PEL, the sample will proceed for elemental analysis. Results will be reported from the elemental analysis for the element only; the stated identity of the actual sample contents is based on the assumption that the material sampled is as identified by the compliance officer using available documentation of materials and processes.

An elemental result provided may be converted to the desired compound by multiplying the result by the appropriate stoichiometric factor. A 91B report specific to the compound (including the stoichiometric conversion) may by be provided upon request by contacting the laboratory. The stoichiometric factor for calcium hydroxide from calcium is 1.849.

Samples collected for this compound are first analyzed gravimetrically. If the gravimetric result of a sample yields a concentration below the permissible exposure limit (PEL), the SLTC will report the calculated air concentration for the requested compound solely from the gravimetric result, qualified as less than or equal to the gravimetric result; no further work on the sample will be performed.

If the gravimetric result indicates an air concentration greater than the PEL, the sample will proceed for elemental analysis. Results will be reported from the elemental analysis for the element only; the stated identity of the actual sample contents is based on the assumption that the material sampled is as identified by the compliance officer using available documentation of materials and processes.

An elemental result provided may be converted to the desired compound by multiplying the result by the appropriate stoichiometric factor. A 91B report specific to the compound (including the stoichiometric conversion) may by be provided upon request by contacting the laboratory. The stoichiometric factor for calcium hydroxide from calcium is 1.849. The standard applies to the Respirable Fraction.

Special requirements

FOR TOTAL DUST, DO NOT USE A CYCLONE!!!

Samples must be collected with a Dorr-Oliver cyclone.

* All sampling instructions above are recommended guidelines for OSHA Compliance Safety and Health Officers (CSHOs), please see the corresponding OSHA method reference for complete details.

Wipe Method
Wipe Method
Sampler/Sampling media
Bulk Method
Bulk Method
On-Site Screening Techniques
On-Site Screening Techniques
Device
Model/Type
Sampling information
(see manufacturer instructions)
Exposure Limits
Exposure Limits
OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
NIOSH REL
Up to 10-hour TWA
(ST) STEL
(C) Ceiling
ACGIH TLV©
8-hour TWA
(ST) STEL
(C) Ceiling
CAL/OSHA PEL
8-hour TWA
(ST) STEL
(C) Ceiling
Peak
PEL-TWA

15 mg/m³ (total dust), 5 mg/m³ (respirable fraction)

REL-TWA

5 mg/m³

TLV-TWA

5 mg/m³ [1979]

PEL-TWA

5 mg/m³

PEL-STEL REL-STEL TLV-STEL PEL-STEL
PEL-C REL-C TLV-C PEL-C
Skin notation

N

Skin notation

N

Skin notation

N

Skin notation

N

Notes:

See 29 CFR 1910.1000 Table Z-1.

Notes: Notes: Notes:
Health factors:  See NIH-NLM PubChem. IDLH
Carcinogenic classifications: Not listed Notes:
AIHA emergency response planning guidelines - ERPG-1/ERPG-2/ERPG-3:
Additional Resources and Literature References
Additional Resources and Literature References

NOAA: CAMEO Chemicals - Calcium hydroxide

NIOSH: Pocket Guide to Chemical Hazards - Calcium hydroxide

Literature References

  • ACGIH: Documentation of the Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) - Calcium hydroxide. See annual publication for most recent information.
  • Pohanish, R.P. (editor): Calcium Hydroxide. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 464-465.
  • Sherman S.C. and Larkin, K.: Cement burns. J. Emerg. Med. 29(1): 97-99, 2005.
  • Spoo, J. and Elsner, P.: Cement burns: a review 1960-2000. Contact Dermatitis 45(2): 68-71, 2001.
  • Winder, C. and Carmody, M.: The dermal toxicity of cement. Toxicol. Ind. Health 18(7): 321-331, 2002.

Last Updated Date : 12/18/2020