CACODYLIC ACID

Chemistry informtion about Cacodylic Acid (CAS NO.75-60-5) is:
IUPAC Name: Dimethylarsinic Acid
Synonyms: Ansar(R) ; Cacodylic Acid ; Cacodylie Acid ; Hydroxydimethylarsine Oxide ; Dimethylhydroxyarsine Oxide ; Dimethylarsinic Acid ; Dimethylarsonic Acid ; Silvisar(R)
MF: C₂H₇AsO₂
MW: 138
EINECS: 200-883-4
Melting Point: 195-198 °C 
Flash Point: 109.4 °C
Boiling Point: 253.1 °C at 760 mmHg
Vapour Pressure: 0.00288 mmHg at 25°C 
Enthalpy of Vaporization: 56.98 kJ/mol
Storage temp.: Store at RT.
Sensitive: Hygroscopic
Merck: 14,1604
BRN: 1736965
Stability: Aqueous solutions react violently with active metals. Incompatible with strong oxidizing agents, strong bases.
Following is the molecular structure of  Cacodylic Acid (CAS NO.75-60-5) is:

Significant early research into cacodyls was done by Robert Bunsen at the University of Marburg. Bunsen said of the compounds, "the smell of this body produces instantaneous tingling of the hands and feet, and even giddiness and insensibility...It is remarkable that when one is exposed to the smell of these compounds the tongue becomes covered with a black coating, even when no further evil effects are noticeable". His work in this field led to an increased understanding of the methyl radical.

Derivatives of  Cacodylic Acid (CAS NO.75-60-5) , cacodylates , were frequently used as herbicides . For example, "Agent Blue," one of the chemicals used during the Vietnam War, is a mixture of cacodylic acid and sodium cacodylate. Sodium cacodylate is frequently used as a buffering agent in the preparation and fixation of biological samples for transmission electron microscopy.

IARC Cancer Review: Animal Inadequate Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 23 , 1980,p. 39.(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) . Arsenic and its compounds are on the Community Right-To-Know List. Reported in EPA TSCA Inventory. EPA Genetic Toxicology Program.

Poison by an unspecified route. Moderately toxic by ingestion and intraperitoneal routes. Experimental teratogenic and reproductive effects. A skin and eye irritant. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. Used as an herbicide, defoliant, and silvicide. Hazardous when water solution is in contact with active metals, e.g., Fe, Al, Zn. When heated to decomposition it emits toxic fumes of As. See also ARSINE and ARSENIC COMPOUNDS.
Hazard Codes:
T: Toxic 
N: Dangerous for the environment
Risk Statements:
R23/25: Toxic by inhalation and if swallowed.  
R50/53: Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. 
Safety Statements:
S20/21: When using, do not eat or drink and do not smoke. 
S28: After contact with skin, wash immediately with plenty of soap-suds.
S45: In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) 
S60: This material and its container must be disposed of as hazardous waste.
S61: Avoid release to the environment. Refer to special instructions / safety data sheets.
RIDADR: UN 1572 6.1/PG 2
WGK Germany: 3
RTECS: CH7525000
F:
F 3: Hygroscopic.
F 10: Keep under argon.
HazardClass: 6.1
PackingGroup: II

OSHA PEL: TWA 0.5 mg(As)/m³
ACGIH TLV: BEI: 35 µ (As)/L inorganic arsenic and methylated metabolites in urine
DOT Classification:  6.1; Label: Poison

For occupational chemical analysis use NIOSH: Arsenic, Organo-, 5022.

General description about Cacodylic Acid (CAS NO.75-60-5) , it is a colorless, odorless crystalline solid.Toxic by ingestion and irritating to skin and eyes.
Air & Water Reactions: Hygroscopic. Water soluble.
Reactivity Profile: It is a weak acid. Dissolves in water to yield solutions containing more hydrogen ions than pure water contains and so having a pH less than 7.0. Is neutralized exothermically by all bases to produce water plus a salt. Reacts (but usually slowly) with active metals to form gaseous hydrogen and a metal salt. Such reactions occur in principle for the solid acid but are quite slow if the solid acid remains dry. The solid may absorb enough water from the air and dissolve sufficiently in it to corrode or dissolve iron, steel, and aluminum parts and containers. Reacts with cyanide salts to generate gaseous hydrogen cyanide. Flammable and/or toxic gases and heat may be generated with diazo compounds, dithiocarbamates, isocyanates, mercaptans, nitrides, and sulfides. Also may react with sulfites, nitrites, thiosulfates (to give H₂S and SO₃), dithionites (SO₂), to generate flammable and/or toxic gases and heat. Reaction with carbonates and bicarbonates generates a harmless gas (carbon dioxide) but still some heat. Can be oxidized exothermically by strong oxidizing agents and reduced by strong reducing agents; a wide variety of products is possible. May initiate polymerization reactions; may catalyze (increase the rate of) chemical reactions.
Health Hazard: Chemical is essentially non-irritating in contact with skin or eyes. Ingestion causes arsenic poisoning, but symptoms are delayed.
Fire Hazard: Behavior in Fire: May form toxic oxides of arsenic when heated.