Calcium oxide

Synonyms: Burned lime; Burnt lime; Lime, Pebble lime; Quicklime; Unslaked lime

OSHA IMIS Code Number: 0520

Chemical Abstracts Service (CAS) Registry Number: 1305-78-8

NIOSH Registry of Toxic Effects of Chemical Substances (RTECS) Identification Number: EW3100000

Department of Transportation Regulation Number (49 CFR 172.101) and Guide: 1910 157

chemical description, physical properties, potentially hazardous incompatibilities, and more

OSHA Permissible Exposure Limit (PEL):

Construction Industry: 29 CFR 1926.55 Appendix A - 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): 2 mg/m3 TWA

National Institute for Occupational Safety and Health (NIOSH) Recommended Exposure Limit (REL): 2 mg/m3 TWA

NIOSH Immediately Dangerous To Life or Health Concentration (IDLH): 25 mg/m3

Potential Symptoms: Irritation of eyes, skin, upper respiratory tract; ulcerated, perforated nasal septum; pneumonitis, pulmonary edema (may be delayed); lacrimation, spasmodic blinking; brittle nails, irritant contact dermatitis

Health Effects: Irritation-Eye, Nose, Throat, Skin-Marked (HE14)

Affected Organs: Eyes, skin, respiratory system

Notes:

1. Calcium oxide is affirmed by the FDA as a generally recognized as safe (GRAS) direct food substance (21 CFR 184.1210).
2. 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.

Literature Basis:

• Cain, W.S., et al.: Sensory and associated reactions to mineral dusts: sodium borate, calcium oxide, and calcium sulfate. J. Occup. Environ. Hyg. 1(4): 222-236, 2004.
• Pohanish, R.P. (editor): Calcium Oxide. In, Sittig's Handbook of Toxic and Hazardous Chemicals and Carcinogens, Fourth Ed., Vol. 1. Norwich, NY: Noyes Publications, William Andrew Publishing, 2002, pp. 468-470.
• 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.

Primary Laboratory Sampling/Analytical Method (SLC1):

Federal OSHA and OSHA State Plan personnel submitting samples to the OSHA Salt Lake Technical Center Laboratory for calcium oxide analysis must use the tared gravimetric sampling media described immediately below.