Beryllium hydride.

IUPAC Name: beryllium hydride
CAS NO: 7787-52-2
Molecular Formula Beryllium hydride (CAS NO.7787-52-2): H₂Be
Molecular Weight: 11.0281
Molecular Structure:

The purest beryllium hydride is obtained by the reaction of triphenylphosphine, PPh₃, with beryllium borohydride, Be(BH₄)₂.
Be(BH₄)₂ + 2PPh₃ → 2Ph₃PBH₃ + BeH₂
BeH₂ was first synthesised in 1951 by reacting dimethylberyllium, Be(CH₃)₂, with lithium aluminium hydride, LiAlH_4.Purer BeH₂ forms from the pyrolysis of di-tert-butylberyllium, Be(C(CH₃)₃)₂ at 210 °C.

IARC Cancer Review: Group 1 IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 58 (1993),p. 41.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Human Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 58 (1993),p. 41.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 1 (1972),p. 17.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 23 (1980),p. 143.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 58 (1993),p. 41.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) . Beryllium and its compounds are on the Community Right-To-Know List.

RIDADR: 1409
HazardClass: 4.3
PackingGroup: II
Confirmed carcinogen. A dangerous fire hazard. When heated to 220°C it liberates explosive hydrogen gas. Reacts violently with methanol, water, and dilute acids. When heated to decomposition it emits toxic fumes of BeO. See BERYLLIUM COMPOUNDS and HYDRIDES.

OSHA PEL: TWA 0.002 mg(Be)/m³; STEL 0.005 mg(Be)/m³/30M; CL 0.025 mg(Be)/m³
ACGIH TLV: TWA 0.002 mg(Be)/m³; Confirmed Human Carcinogen; (Proposed: TWA 0.0002 mg(Be)/m³ (sensitizer); Confirmed Human Carcinogen); TWA 2.5 mg(F)/m³; BEI: 3 mg/g creatinine of fluorides in urine prior to shift; 10 mg/g creatinine of fluorides in urine at end of shift.
NIOSH REL: (Beryllium) CL not to exceed 0.0005 mg(Be)/m³