Product Identification

Product Name

Methidathion

Synonyms

Methidathion
O,O-Dimethyl-S-(2-methoxy-1,3,4-thiadiazol-5(4H)-onyl-4-methyl) dithiophosphate
Phosphorodithioic acid, S-[(5-methoxy-2-oxo-1,3,4-thiadiazol-3(2H)-yl)methyl] O,O-dimethyl ester
S-(2,3-Dihydro-5-methoxy-2-oxo-1,3,4-thiadiazol-3-methyl)dimethylphosphorothiolothionate
Ultracide

CAS

950-37-8

Formula

C6H11N2O4PS3

Molecular Weight

302.33999999999997

EINECS

213-449-4

RTECS

TE2100000

RTECS Class

Agricultural Chemical and Pesticide; Mutagen; Human Data; Primary Irritant

Merck

12,6048

Beilstein/Gmelin

619915

EC Index Number

015-069-00-2

EC Class

Very toxic; Harmful; Dangerous for the Environment

Physical and Chemical Properties

Appearance

Colorless crystals.

Solubility in water

at 20 C: 250 mg/L

Melting Point

39-40

Vapor Pressure

.000001

Density

1.495 g/cm3 (20 C)

Partition Coefficient

2.47

Usage

Methidathion is used in the control of scale insects, leaf eaters, and some mites.

First Aid Measures

Ingestion

Seek medical assistance.

Inhalation

Move victim to fresh air. Apply artificial respiration if victim is not breathing. Do not use mouth-to-mouth method if victim ingested or inhaled the substance; induce artificial respiration with the aid of a pocket mask equipped with a one-way valve or other proper respiratory medical device. Administer oxygen if breathing is difficult. Remove and isolate contaminated clothing and shoes.

Skin

Remove and isolate contaminated clothing and shoes. In case of contact with substance, immediately flush with running water for at least 20 minutes. Wash skin with soap and water.

Eyes

In case of contact with substance, immediately flush with running water for at least 20 minutes.

Handling and Storage

Storage

Store at in dry place above 32 degrees F to prolong shelf-life.

Handling

All chemicals should be considered hazardous. Avoid direct physical contact. Use appropriate, approved safety equipment. Untrained individuals should not handle this chemical or its container. Handling should occur in a chemical fume hood.

Hazards Identification

Inhalation

Dyspnea, rales, bronchorrhea, bronchospasm, or tachypnea may be noted. Noncardiogenic pulmonary edema may occur in severe cases. Chemical pneumonitis may be seen.

Skin

Sweating is a consistent but not universal sign.

Eyes

Constriction of the pupil, tearing, and blurred vision are common. Prolonged dialation of the pupils may occur in severe poisonings. Opsoclonus has been reported in one case. Salivation commonly occurs.

Ingestion

Vomiting, hypersalivation, diarrhea, fecal incontinence and abdominal pain may occur.

Hazards

Container may explode in heat of fire. Fire and runoff from fire control water may produce irritating or poisonous gases. Stable in neutral or weak acid solution. Hydrolyzed by alkali.

UN (DOT)

2784

Exposure Controls/Personal Protection

Personal Protection

Wear appropriate protective gloves, clothing and goggles.

Respirators

Wear positive pressure self-contained breathing apparatus (SCBA).

Exposure Effects

Fever, low heart rate and abnormally low blood pressure, or rapid heart rate and elevated blood pressure may occur. Headache, dizziness, muscle spasms and profound weakness are common. Alterations of level of consciousness, anxiety, paralysis, seizures and coma may occur. Seizures may be more common in children.

Poison Class

2

Fire Fighting Measures

Fire Fighting

(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Stay upwind; keep out of low areas. Move container from fire area if you can do so without risk. Fight fire from maximum distance. Dike fire control water for later disposal; do not scatter the material. Wear positive pressure breathing apparatus and special protective clothing.(Non-Specific -- Organophosphorus Pesticide, n.o.s.) This material may burn, but does not ignite readily. For small fires, use dry chemical, carbon dioxide, water spray, or foam. For large fires, use water spray, fog, or foam.

Fire Potential

HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames.

Accidental Release Measures

Small spills/leaks

(Non-Specific -- Organophosphorus Pesticide, n.o.s.) Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Do not touch spilled material; stop leak if you can do so without risk. Use water spray to reduce vapors. Small spills: absorb with sand or other noncombustible absorbent material and place into containers for later disposal. Small dry spills: with clean shovel place material into clean, dry containers and cover; move containers from spill area. Large spills: dike far ahead of spill for later disposal.

Stability and Reactivity

Stability

No data.

Combustion Products

Fire will produce irritating, corrosive and/or toxic gases.

Transport Information

UN Number

2784

Hazard Class

3

Packing Group

I; II