Monocrothophos

  • Dimethyl (E)-1-methyl-2-(methylcarbamoyl) vinyl phosphate
  • Phosphoric acid, dimethyl 1-methyl-3-(methyamino)-3-oxo-1-propenyl ester, (E)
  • 3-Hydroxy-n-methylcrotonamide dimethylphosphate
Formula
C7H14NO5P
Structure
Description
Reddish brown solid. Mild, ester odor.
Uses
Acaricide, insecticide.

Registry Numbers and Inventories.
CAS
6923-22-4
EC (EINECS/ELINCS)
230-042-7
EC Index Number
015-072-00-9
EC Class
Mutagenic Category 3; Very toxic; Toxic; Dangerous for the Environment
RTECS
TC4375000
RTECS class
Agricultural Chemical and Pesticide; Mutagen; Reproductive Effector
UN (DOT)
2783
Merck
12,6334
Beilstein/Gmelin
2331934
EPA OPP
58901
Swiss Giftliste 1
G-4301
Austrailia AICS
Listed
Korea ECL
Listed

Properties.
Formula
C7H14NO5P
Formula mass
223.17
Melting point, °C
54 - 55
Boiling point, °C
315
Vapor pressure, mmHg
0.00045 (25 C)
Density
1.33 g/cm3 (20 C)
Solubility in water
Miscible
pKa/pKb
13.31 (pKa)
Partition coefficient, pKow
-0.20
Heat of vaporization
55.6 kJ/mol

Hazards and Protection.
Storage
Keep in a cool, dry, dark location in a tightly sealed container or cylinder. Keep away from incompatible materials, ignition sources and untrained individuals. Secure and label area. Protect containers/cylinders from physical damage.
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.
Protection
Wear appropriate protective gloves, clothing and goggles.
Respirators
Wear positive pressure self-contained breathing apparatus (SCBA).
Small spills/leaks
As with other organophosphorus pesticides, do not touch spilled material; stop leak if you can do it without risk. Use water spray to reduce vapors. Small spills: take up 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 container and cover; move containers from spill area. Large spills: dike far ahead of spill for later disposal. Keep unnecessary people away; isolate hazard area and deny entry. Stay upwind; keep out of low areas. Ventilate closed spaces before entering them. Remove and isolate contaminated clothing at the site.
Stability
No data.
Incompatibilities
Incompatible with the following: Metals, low molecular weight alcohols & glycols Corrosive to black iron, drum steel, stainless steel 304 & brass Incompatible with alkaline compounds.
Decomposition
When heated to decomposition it emits very toxic fumes. Decomposes > 38 C, thermal runaway reactions can occur > 55 C. Decomposes on some inert materials (care should be taken when carrying out chromatography).

Fire.
Flash Point,°C
144
Fire fighting
Like other organophosphorus pesticides, 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.Like other organophosphorus pesticides, extinguish with dry chemical, carbon dioxide, water spray, fog, or foam.
Fire potential
Azodrin 5 is extremely flammable.
Hazards
Wear positive pressure breathing apparatus and full protective clothing. Container may explode in heat of fire. Toxic fumes evolved when heated to decomposition. Incompatible with alkaline compounds. Unstable in aqueous solution above pH 7.0; in low molecular weight alcohols and glycols. Stable in ketones and higher molecular weight alcohols and glycols. Stable when stored in glass or polyethylene containers. Relatively stable in sunlight. Keep away from temperatures above 80F; do not store below 70F. Corrosive to black iron, drum steel, stainless steel 304 and brass, but not to glass, aluminum, or stainless steel 316.
Combustion products
Fire may produce irritating, corrosive and/or toxic gases.

Health.
Exposure limit(s)
TLV: 0.25 ppm; mg/m3 (skin) (ACGIH 1994-1995). NIOSH REL: TWA 0.25 mg/m3
Poison_Class
2
Exposure effects
Reduced body temperature or elevated body temperature may occur. Low heart rate and abnormally low blood pressure may develop after moderate to severe poisoning. Rapid heart rate, elevated blood pressure, and changes in respiratory rate may also occur. Early giddiness, anxiety headache, and restlessness followed by ataxia, drowsiness, and confusion are common with moderate to severe exposures. Sporadic reports of human birth defects related to organophosphates have not been fully verified.
   Ingestion
Vomiting, hypersalivation, diarrhea, fecal incontinence and abdominal pain may occur.
   Inhalation
Dyspnea, rales, bronchorrhea, bronchospasm, hyperventilation, 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.

First aid
 
   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.
   Skin
Remove and isolate contaminated clothing and shoes. Immediately flush with running water for at least 20 minutes. For minor skin contact, avoid spreading material on unaffected skin.
   Eyes
Immediately flush with running water for at least 20 minutes.

Transport.
UN number
2783
Response guide
Hazard class
6.1
Packing Group
I; II; III
 
USCG CHRIS Code
MNP