Gallium arsenide

Synonyms

Gallium monoarsenide; [HSDB]

Category

Arsenic Compounds, Inorganic

Description

Gray crystals or powder; [CAMEO]

Sources/Uses

Used in semiconductor applications; [Merck Index #4347]

Comments

Its toxicity is due to arsenic, and exposed workers can be monitored by urine arsenic levels. [Harrison RJ, State of the Art Reviews: Occupational Medicine, Vol. 1, No. 1, pages 49-58.] Inhalation studies in experimental rats show that both gallium and arsenic are cleared within 14 days after treatment. [Webb DR et al. Pulmonary Clearance and Toxicity of Respirable Gallium Arsenide Particulates. Am Ind Hyg Assoc J. 1987 Jul;48(7):660-7.] Gallium arsenide is "poorly absorbed"; it is excreted primarily in the feces. [Rosenstock, p. 947] Toxic arsenic released when heated to decomposition; [CAMEO] "Metalloid arsenic is generally regarded as nonpoisonous due to its insolubility in water and body fluids." [ATSDR Case Studies: Arsenic Toxicity] Gallium arsenide is classified as a human carcinogen. [IARC] "Because of its ability to cause extensive pulmonary damage in the rat at a level of 10 μg/m3 and in the mouse at a level of 100 mg/m3 for particles of 1 μm or smaller and because of its ability to cause cancer in female rats (but not male rats), a TLV–TWA of 0.3 μg/m3 (0.0003 mg/m3) is recommended, with an A3, Confirmed Animal Carcinogen with Unknown Relevance to Humans, designation." [ACGIH] See "Arsenic" and the linked occupational diseases.

Reference Link #1

Biomedical References

"Due to the insolubility of gallium arsenide, however, the BEI is not recommended as an index of exposure." [ACGIH]

No

Yes

0.0003 mg/m3, respirable fraction

Explanatory Notes

NIOSH REL = 15 min ceiling of 0.002 mg/m3; Melting point = 1238 deg C; [Merck Index] Known human carcinogen "as As." [IARC]

Aplastic anemia

Sensorimotor

Hepatoxic (a) from occupational exposure (secondary effect) or (b) in animal studies or in humans after ingestion

Yes

Established

Confirmed Animal

Diseases

Occupational diseases associated with exposure to this agent:

• Arsenic, chronic toxic effect

Processes

Industrial Processes with risk of exposure:

• Semiconductor Manufacturing