The IUPAC name of Mercuric arsenate (CAS NO.7784-37-4): arsoric acid; mercury
Synonyms: Mercuric arsenate ; Mercury(Ⅱ)arsenate ; Mercuric (II)arsenate ; Mercury(ii)o-arsenate ; Mercuryhydrogenarsenate ; Mercury(II) hydrogen arsenate ; Arsenic acid mercury(I) salt
CAS: 7784-37-4
EINECS: 232-062-1
Molecular Formula: AsHHgO₄
Formula Weight: 340.52 g/mol
Molecular Structure:

General Description: A yellow powder. Insoluble in water. Soluble in hydrochloric acid. Toxic by ingestion, skin absorption and inhalation. A strong irritant. Used to make waterproof paints.
Air & Water: Reactions Insoluble in water.
 

The toxicity of Mercuric arsenate (CAS NO.7784-37-4):
ACGIH TLV-TWA 0.025 mg(Hg)/m3 (skin) DTLVS* The Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) booklet issues by American Conference of Governmental Industrial Hygienists (ACGIH), Cincinnati, OH, 1996 Volume(issue)/page/year: TLV/BEI,1997 ACGIH TLV-TWA 0.01 mg(As)/m3 DTLVS* The Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) booklet issues by American Conference of Governmental Industrial Hygienists (ACGIH), Cincinnati, OH, 1996 Volume(issue)/page/year: TLV/BEI,1997 ACGIH TLV-Not classifiable as a human carcinogen DTLVS* The Threshold Limit Values (TLVs) and Biological Exposure Indices (BEIs) booklet issues by American Conference of Governmental Industrial Hygienists (ACGIH), Cincinnati, OH, 1996 Volume(issue)/page/year: TLV/BEI,1997

Mercury and its compounds, as well as arsenic and its compounds, are on the Community Right-To-Know List.

The Health Hazard of Mercuric arsenate (CAS NO.7784-37-4):
Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution.
Fire Hazard: Non-combustible, substance itself does not burn but may decompose upon heating to produce corrosive and/or toxic fumes. Containers may explode when heated. Runoff may pollute waterways.
Confirmed human carcinogen. A poison. When heated to decomposition it emits very toxic fumes of Hg and As. See also MERCURY and ARSENIC COMPOUNDS.

OSHA PEL: 0.01 mg(As)/m³; Cancer Hazard; CL 0.1 mg(Hg)/m³ (skin)
ACGIH TLV: TWA 0.01 mg/m³; Confirmed Human Carcinogen; BEI: 35 µ (As)/L inorganic arsenic and methylated metabolites in urine; BEI: 35 µg/g creatinine total inorganic mercury in urine preshift; 15 µg/g creatinine total inorganic mercury in blood at end of shift at end of workweek.
NIOSH REL: (Arsenic, Inorganic) CL 0.002 mg(As)/m³/15M; (Mercury, Aryl and Inorganic) CL 0.1 mg/m³ (skin)
DOT Classification:  6.1; Label: Poison