Beryllium compounds (as Be)

The content of this page is from the NIOSH Documentation for Immediately Dangerous to Life or Health Concentrations (IDLHs) (1994)pdf icon. The IDLH value for beryllium has not changed, but other information on this page has been changed, including updated exposure limits, updated respirator recommendations, and a new NIOSH Carcinogen Policy.  For the most up to date information on Beryllium see the NIOSH Pocket Guide to Chemical Hazards.

May 1994
Immediately Dangerous to Life or Health Concentrations (IDLH)

CAS number 7440-41-7 (Metal)

NIOSH REL Not to exceed 0.0005 mg/m3; NIOSH considers beryllium compounds to be potential occupational carcinogens as defined by the OSHA carcinogen policy [29 CFR 1990].

Current OSHA PEL 0.002 mg/m3 TWA, 0.005 mg/m3 CEILING, 0.025 mg/m3 30-minute MAXIMUM PEAK

1989 OSHA PEL Same as current PEL

1993-1994 ACGIH TLV 0.002 mg/m3 TWA, A2

Description of Substance Varies

Original (SCP) IDLH* 10 mg Be/m3 [*Note: “Effective” IDLH = 4 mg Be/m3 — see discussion below.]

Basis for original (SCP) IDLH This IDLH is based on the statement by Patty [1963] that 10 mg/m3 of beryllium fluoride was lethal to several species in 15 days. However, respirators have been assigned on the basis of the assigned protection factor afforded by each device up to 2,000 x the OSHA PEL of 0.002 mg/m3 (i.e., 4 mg/m3); only the “most protective” respirators are permitted for use in concentrations exceeding 4 mg Be/m3.

Short-term exposure guidelines None developed


Lethal dose data:

Species Reference Route LD50(mg/kg) LDLo(mg/kg) Adjusted LD Derived Value
Rat Blair 1951 oral 90 —– 158 mg Be/m3 16 mg Be/m3
Mouse Tabershaw 1972 oral 100 —– 161 mg Be/m3 16 mg Be/m3
Rat Sazhina 1965 oral 82 —– 49 mg Be/m3 4.9 mg Be/m3
Mouse Sazhina 1965 oral 80 —– 48 mg Be/m3 4.8 mg Be/m3

Other animal data: It has been reported that 10 mg/m3 of beryllium fluoride (i.e., 2.3 mg Be/m3) was lethal to several species in 15 days [Patty 1963].

Human data: None relevant for use in determining the revised IDLH.


      1. Blair HA [1951]. Quarterly technical report (January 1, 1951 through March 31, 1951). Rochester, NY: University of Rochester, Research and Development Report UR-154, U.S. Atomic Energy Commission Contract W-7401-eng-49.
      2. Patty FA, ed. [1963]. Industrial hygiene and toxicology. 2nd rev. ed. Vol. II. Toxicology. New York, NY: Interscience Publishers, Inc., p. 1006.
      3. Sazhina LA [1965]. Experimental data to substantiate the maximum permissible concentration of beryllium in the water of reservoirs. Gig Sanit 30(1-3):169-176 (translated).
      4. Tabershaw IR, ed. [1972]. The toxicology of beryllium. U.S. Public Health Service Publication 2173:23.
Page last reviewed: May 10, 2019