Section 1 - CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME

OMETHOATE

NFPA

PRODUCT USE

Dangerous POISON. Available ONLY for industrial and manufacturing purposes. To be used by
or in accordance with directions of accredited pest control officers. Operators to be
trained in procedures for safe use of material. Concentrate active used in systemic
insecticide and acaricide preparations with contact and stomach action. Controls spider
mites, aphids (including wooly aphids), beetles, caterpillars, scale insects, thrips,
suckers, thrips, fruit flies, etc. on fruit, hops, cereals, rice, potatoes, ornamentals
and other crops. Regeant

SYNONYMS

C5-H12-N-O4-P, C5-H12-N-O4-P, "O, O-dimethyl-S-(N-methylcarbamoylmethyl)
phosphorothioate", "O, O-dimethyl-S-(N-methylcarbamoylmethyl) phosphorothioate", "O, O-
dimethyl S-(2-(methylamino)-2-oxoethyl)phosphorothioate", "O, O-dimethyl S-(2-
(methylamino)-2-oxoethyl)phosphorothioate", "O, O-dimethyl-S-
((methylcarbamoyl)methyl)phosphorothioate", "O, O-dimethyl-S-
((methylcarbamoyl)methyl)phosphorothioate", dimethyl-S-(N-methyl-carbamoyl-
methyl)phosphorothiolate, dimethyl-S-(N-methyl-carbamoyl-methyl)phosphorothiolate,
"acetamide, 2-mercapto-N-methyl, S-ester with O, O-dimethyl phosphorothioate",
"acetamide, 2-mercapto-N-methyl, S-ester with O, O-dimethyl phosphorothioate", "O, O-
dimethyl S-(N-methylcarbamoylmethyl) thiophosphate", "O, O-dimethyl S-(N-
methylcarbamoylmethyl) thiophosphate", "phosphorothioic acid, O, O-dimethyl S-(2-
(methylamino)-2-oxoethyl) ester", "phosphorothioic acid, O, O-dimethyl S-(2-
(methylamino)-2-oxoethyl) ester", "Bay 45432", P-O-Rogor, P-O-Rogor, "Bayer 45, 432",
"dimethoate O-analogue", "dimethoate O-analogue", "dimethoate oxygen analogue",
dimethoxon, folimat, po-dimethoate, "omethoate insecticide", S6876

Section 2 - HAZARDS IDENTIFICATION

CANADIAN WHMIS SYMBOLS

EMERGENCY OVERVIEW

RISK

Harmful in contact with skin.
Toxic if swallowed.
Very toxic to aquatic organisms.

POTENTIAL HEALTH EFFECTS

ACUTE HEALTH EFFECTS

SWALLOWED

  Toxic effects may result from the accidental ingestion of the material; animal experiments indicate that ingestion of less than 40 gram may be fatal or may produce serious damage to the health of the individual.  Limited evidence exists that the substance may cause irreversible but non-lethal mutagenic effects following a single exposure.  Ingestion may produce nausea, vomiting, depressed appetite, abdominal cramps,and diarrhea.  Symptoms may be nausea, headache, giddiness, blurred vision, contractionof pupils, vomiting.  

EYE

  There is some evidence to suggest that this material can causeeye irritation and damage in some persons.  Direct eye contact can produce tears, eyelid twitches, pupil contraction, loss of focus, and blurred or dimmed vision. Dilation of the pupils occasionally occurs.  

SKIN

  Skin contact with the material may be harmful; systemic effects may resultfollowing absorption.  The material is not thought to be a skin irritant (as classified using animal models). Temporary discomfort, however, may result from prolonged dermal exposures. Good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.  There may be sweating and muscle twitches at site of contact. Reaction may bedelayed by hours.  Entry into the blood-stream, through, for example, cuts, abrasions or lesions, may produce systemic injury with harmful effects. Examine the skin prior to the use of the material and ensure that any external damage is suitably protected.  Absorption by skin may readily exceed vapor inhalation exposure. Symptoms for skin absorption are the same as for inhalation.  

INHALED

  The material is not thought to produce respiratory irritation (as classified using animal models). Nevertheless inhalation of vapors, fumes or aerosols, especially for prolonged periods, may produce respiratory discomfort and occasionally, distress.  Inhalation of vapors or aerosols (mists, fumes), generated by the material during the course of normal handling, may produce serious damage to the health of the individual.  Inhalation hazard is increased at higher temperatures.  Poisoning due to cholinesterase inhibitors causes symptoms such as increased blood flow to the nose, watery discharge, chest discomfort, shortness of breath and wheezing. Other symptoms include increased production of tears, nausea and vomiting, diarrhea, stomach pain, involuntary passing of urine and stools, chest pain, breathing difficulty, low blood pressure, irregular heartbeat, loss of reflexes, twitching, visual disturbances, altered pupil size, convulsions, lung congestion, coma and heart failure. Nervous system effects include inco-ordination, slurred speech, tremors of the tongue and eyelids, and paralysis of the limbs and muscles of breathing, which can cause death, although death is also seen due to cardiac arrest.  Limited evidence exists that the substance may cause irreversible but non-lethal mutagenic effects following a single exposure.  

CHRONIC HEALTH EFFECTS

  Limited evidence suggests that repeated or long-term occupational exposure may produce cumulative health effects involving organs or biochemical systems.  Exposure to the material may result in a possible risk of irreversible effects. The material may produce mutagenic effects in man. This concern is raised, generally, on the basis ofappropriate studies with similar materials using mammalian somatic cells in vivo. Such findings are often supported by positive results from in vitro mutagenicity studies.  Repeated or prolonged exposures to cholinesterase inhibitors produce symptoms similar to acute effects. In addition workers exposed repeatedly to these substances may exhibit impaired memory and loss of concentration, severe depression and acute psychosis, irritability, confusion, apathy, emotional liability, speech difficulties, headache, spatial disorientation, delayed reaction times, sleepwalking, drowsiness or insomnia. An influenza-like condition with nausea, weakness, anorexia and malaise has been described. There is a growing body of evidence from epidemiological studies and from experimental laboratory studies that short-term exposure to some cholinesterase-inhibiting insecticides may produce behavioral or neuro- chemical changes lasting for days or months,  presumably outlasting the cholinesterase inhibition. Although the number of adverse effects following humans poisonings subside, there are still effects in some workers months after cholinesterase activity returns to normal. These long-lasting effects include blurred vision, headache, weakness, and anorexia. The neurochemistry of animals exposed to chlorpyrifos or fenthion is reported to be altered permanently after a single exposure. These effects may be more severe in developing animals where both acetyl- and butyrylcholinesterase may play an integral part in the development of the nervous system. Padilla S., The Neurotoxicity of Cholinesterase-Inhibiting Insecticides: Past and Present Evidence Demonstrating Persistent Effects. Inhalation Toxicology 7:903-907, 1995.  BE AWARE: Repeated minor exposures with only mild symptoms may have serious cumulative poisoning effect.