NIOSH Publication No. 2005-151:

NIOSH Pocket Guide to Chemical Hazards

September 2005

Arsenic (inorganic compounds, as As)

7440-38-2 (metal)

As (metal)

CG0525000 (metal)
Synonyms & Trade Names

Arsenic metal: Arsenia
Other synonyms vary depending upon the specific As compound. [Note: OSHA considers "Inorganic Arsenic" to mean copper acetoarsenite & all inorganic compounds containing arsenic except ARSINE.]
DOT ID & Guide
1558 / 152 (metal)
1562 / 152 (dust)


NIOSH REL: Ca C 0.002 mg/m3 [15-minute] See Appendix A
OSHA PEL: [1910.1018] TWA 0.010 mg/m3
Ca [5 mg/m3 (as As)] See: 7440382
Physical Description
Metal: Silver-gray or tin-white, brittle, odorless solid.
MW: 74.9
BP: Sublimes
MLT: 1135°F (Sublimes)
Sol: Insoluble
VP: 0 mmHg (approx)

Sp.Gr: 5.73 (metal)
Fl.P: NA

Metal: Noncombustible Solid in bulk form, but a slight explosion hazard in the form of dust when exposed to flame.
Incompatibilities & Reactivities

Strong oxidizers, bromine azide [Note: Hydrogen gas can react with inorganic arsenic to form the highly toxic gas arsine.]
Measurement Methods
NIOSH 7300, 7301, 7303, 7900, 9102; OSHA ID105
See: NMAM or OSHA Methods
Personal Protection & Sanitation
(See protection)
Skin: Prevent skin contact
Eyes: Prevent eye contact
Wash skin: When contaminated/Daily
Remove: When wet or contaminated
Change: Daily
Provide: Eyewash, Quick drench
First Aid
(See procedures)
Eye: Irrigate immediately
Skin: Soap wash immediately
Breathing: Respiratory support
Swallow: Medical attention immediately
Respirator Recommendations
(See Appendix E) NIOSH
At concentrations above the NIOSH REL, or where there is no REL, at any detectable concentration:
(APF = 10,000) Any self-contained breathing apparatus that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode
(APF = 10,000) Any supplied-air respirator that has a full facepiece and is operated in a pressure-demand or other positive-pressure mode in combination with an auxiliary self-contained positive-pressure breathing apparatus
(APF = 50) Any air-purifying, full-facepiece respirator (gas mask) with a chin-style, front- or back-mounted acid gas canister having an N100, R100, or P100 filter. Click here for information on selection of N, R, or P filters./Any appropriate escape-type, self-contained breathing apparatus
Important additional information about respirator selection
Exposure Routes
inhalation, skin absorption, skin and/or eye contact ingestion
Ulceration of nasal septum, dermatitis, gastrointestinal disturbances, peripheral neuropathy, respiratory irritation, hyperpigmentation of skin, [potential occupational carcinogen]
Target Organs
Liver, kidneys, skin, lungs, lymphatic system

Cancer Site
[lung & lymphatic cancer]
See also: INTRODUCTION   See ICSC CARD: 0013   See MEDICAL TESTS: 0017