• Cela s 2957
  • Celathion
  • o-(2,5-Dichloro-4-(methylthio)phenyl) O,O-diethyl phosphorothioate
  • NSC 195164
  • Oms 1342
Yellow-brown liquid which tends to crystallize at less than 77F.
Materials believed to be no longer manufactured, or marketed for crop protection use.

Registry Numbers and Inventories.
EC Index Number
EC Class
Very toxic; Toxic
RTECS class
Agricultural Chemical and Pesticide

Formula mass
Boiling point, °C
150 (0.001 torr)
Vapor pressure, mmHg
1.345 g/cm3 (20 C)
Solubility in water
practically insoluble

Hazards and Protection.
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.
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.
Workers handling and applying organophosphate pesticides must be given personal protective equipment comprising overalls made of a tight fabric or polyvinyl chloride, gloves, and rubber boots. The eyes should be protected by goggles.
Respiratory protection (supplied-air respirator with full facepiece or self-contained breathing apparatus) should be available where these compounds are manufactured or used and should be worn in case of emergency and overexposure.<BR>Wear a respirator with an activated-carbon gas filter cartridge affording protection for a determined number of working hours.
Small spills/leaks
(Non-Specific -- Organophosphorus Pesticide, Liquid, 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 non-combustible absorbent material and place into containers for later disposal. Large spills: dike far ahead of spill for later disposal.
No data.

Fire fighting
(Non-Specific -- Organophosphorus Pesticide, Liquid, n.o.s.) Stay upwind; keep out of low areas. Move containers 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.(Non-Specific -- Organophosphorus Pesticide, Liquid, 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.

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.
Vomiting, hypersalivation, diarrhea, fecal incontinence and abdominal pain may occur.
Dyspnea, rales, bronchorrhea, bronchospasm, or tachypnea may be noted. Noncardiogenic pulmonary edema may occur in severe cases. Chemical pneumonitis may be seen.
Sweating is a consistent but not universal sign.
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
Seek medical attention. If individual is drowsy or unconscious, do not give anything by mouth; place individual on the left side with the head down. Contact a physician, medical facility, or poison control center for advice about whether to induce vomiting. If possible, do not leave individual unattended.
Move patient to fresh air. Monitor for respiratory distress. If cough or difficulty breathing develops, evaluate for respiratory tract irritation, bronchitis, or pneumonitis. Administer oxygen and assist ventilation as required. Treat bronchospasm with beta2 agonist and corticosteroid aerosols.
Systemic effects can occur from dermal exposure to organophosphates. Remove contaminated clothing, wash skin, hair and nails vigorously with repeated soap washings. Leather absorbs pesticides; all contaminated leather should be discarded. Rescue personnel and bystanders should avoid direct contact with contaminated skin, clothing, or other objects.
Irrigate exposed eyes with copious amounts of tepid water for at least 15 minutes. If irritation, pain, swelling, lacrimation, or photophobia persist, the patient should be seen in a health care facility. Patients symptomatic following exposure should be observed in a controlled setting until all signs and symptoms have fully resolved. Suction oral secretions until atropinization. Treatment should include recommendations listed in the oral exposure section when appropriate. Contraindications - succinylcholine and other cholinergic agents are contraindicated. Note: see treatment of eye exposure in the main body of this document for complete information.