Sodium arsenite

Sodium arsenite usually refers to the inorganic compound with the formula NaAsO₂. Also called sodium meta-arsenite, it is an inorganic polymer consisting of the infinite chains [AsO₂]ⁿ⁻
_n associated with sodium cations, Na⁺. The polymer backbone has the connectivity -O-As(O⁻)-.^[2]backbone. Sodium ortho-arsenite is Na₃AsO₃.^[3] Both compounds are colourless solids. A mixture of sodium meta-arsenite and sodium ortho-arsenite is produced by treating arsenic trioxide with sodium carbonate or sodium hydroxide.^[4] Sodium arsenite is amorphous, typically being obtained as a powder or as a glassy mass.

Sodium arsenite

Names
IUPAC name sodium arsenite
Other names sodium arsenate(III)
Identifiers
CAS Number	7784-46-5 Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:29678 Y
ChEMBL	ChEMBL1909078
ChemSpider	22980
DrugBank	DB18508
ECHA InfoCard	100.029.154
EC Number	232-070-5
KEGG	C11906 Y
PubChem CID	443495
RTECS number	CG3675000
UNII	48OVY2OC72 Y
UN number	1686 2027
CompTox Dashboard (EPA)	DTXSID5020104
InChI Key: PTLRDCMBXHILCL-UHFFFAOYSA-M InChI=1S/AsHO2.Na/c2-1-3;/h(H,2,3);/q;+1/p-1
SMILES [O-][As]=O.[Na+]
Properties
Chemical formula	NaAsO2
Molar mass	129.91 g/mol
Appearance	white or grayish powder hygroscopic
Density	1.87 g/cm 3
Melting point	550 °C (1,022 °F; 823 K) decomposes
Solubility in water	156 g/100 mL
Solubility	slightly soluble in alcohol
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H300, H301, H310, H331, H350, H410
Precautionary statements	P201, P202, P261, P262, P264, P270, P271, P273, P280, P281, P301+P310, P302+P350, P302+P352, P304+P340, P308+P313, P310, P311, P312, P321, P322, P330, P361, P363, P391, P403+P233, P405, P501
NFPA 704 (fire diamond)	4 0 0
Lethal dose or concentration (LD, LC):
LD50 (median dose)	41 mg/kg (rat, oral)
NIOSH (US health exposure limits):
PEL (Permissible)	[1910.1018] TWA 0.010 mg/m3[1]
REL (Recommended)	Ca C 0.002 mg/m3 [15-minute][1]
IDLH (Immediate danger)	Ca [5 mg/m3 (as As)][1]
Safety data sheet (SDS)	External MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). N verify (what is YN ?) Infobox references

Health effects

Sodium arsenite can be inhaled or absorbed through the skin. Along with its known carcinogenic and teratogenic effects, contact with the substance can yield symptoms such as skin irritation, burns, itching, thickened skin, rash, loss of pigment, poor appetite, a metallic or garlic taste, stomach pain, nausea, vomiting, diarrhea, convulsions, decreased blood pressure, and headache. Severe acute poisoning may lead to nervous system damage resulting in weakness, poor coordination, or “pins and needles” sensations, eventual paralysis, and death.^[5][6]

Application

Sodium arsenites are primarily used as a pesticide, but has other uses such as hide preservative, antiseptic, dyeing, and soaps.^[7]

Sodium arsenite is an appropriate chemical stressor to induce the production of heat shock proteins,^[8] and the formation of cytoplasmic stress granules.^[9]

Sodium arsenite can be used as a reducing agent in organic chemistry, as it is able to reduce a trihaloalkane to a dihaloalkane:^{[citation needed]}

CHBr₃ + Na₃AsO₃ + NaOH → CH₂Br₂ + Na₃AsO₄ + NaBr

Safety

The LD₅₀ (oral, mouse) is 40 mg/kg.^[4]