Synonyms: Calcium hydrate; Caustic lime; Hydrated lime; Slaked lime
OSHA IMIS Code Number: C330
Chemical Abstracts Service (CAS) Registry Number: 1305-62-0
NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: EW2800000
NIOSH Pocket Guide to Chemical Hazards, Calcium hydroxide: chemical description, physical properties, potentially hazardous incompatibilities, and more
OSHA Permissible Exposure Limit (PEL):
General Industry: 29 CFR 1910.1000 Table Z-1 - 5 mg/m3 TWA
Maritime: 29 CFR 1915.1000 Table Z-Shipyards - 5 mg/m3 TWA
American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV): 5 mg/m3 TWA
National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 5 mg/m3 TWA
Potential Symptoms: Irritation of eyes, skin, upper respiratory system; eye, skin burns; skin vesiculation; cough, bronchitis, pneumonitis
Health Effects: Irritation-Eye, Nose, Throat, Skin---Marked (HE14)
Affected Organs: Eyes, skin, respiratory system
- Calcium hydroxide is affirmed by the FDA as a generally recognized as safe (GRAS) direct food substance (21 CFR 184.1205).
- Prolonged contact with wet cement, which is alkaline due to the reaction of water with calcium oxide to form calcium hydroxide, can result in full-thickness skin burns that may require surgical treatment.
- NIOSH Pocket Guide to Chemical Hazards: Calcium hydroxide.
- International Chemical Safety Cards (WHO/IPCS/ILO): Calcium hydroxide.
- 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.
Date Last Revised: 06/04/2007
Primary Laboratory Sampling/Analytical Method (SLC1):
- sampling media: Tared 37-mm diameter low-ash polyvinyl chloride filter preceded by 10 mm Nylon Cyclone
maximum volume: 816 Liters
minimum volume: 408 Liters
maximum flow rate: 1.7 L/min
current analytical method: Gravimetric
method reference: OSHA Analytical Method (OSHA PV2121)
method classification: Partially Validated
note: OSHA personnel can obtain tared sampling media from the Salt Lake Technical Center.
note: If the net weight of the sample yields a concentration below the standard for the substance, the Salt Lake Technical Center will perform no further work on that sample. If the net weight corresponds to an amount greater than the standard, the sample may be analyzed for the appropriate element and the result reported as the substance.
current elemental analysis method: Atomic Absorption Spectroscopy; AAS
method reference: OSHA Analytical Method (OSHA ID-121)
method classification: Fully Validated
note: Submit as a separate sample. When analysis of a compound is requested, an elemental analysis is performed and reported as the compound. The analytical method does not distinguish between dust and fume.
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