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Bulgaria - Final Regulatory Action
Methyl parathion CAS number:
Date circular:

Chemical name: O,O-Dimethyl O-4-nitrophenyl phosphorothioate

Final regulatory action has been taken for the category: Pesticide

Final regulatory action: The chemical is Banned

Use or uses prohibited by the final regulatory action:

All formulations and uses are prohibited.

Pesticide use or uses that remain allowed:


The final regulatory action was based on a risk or hazard evaluation: No

Summary of the final regulatory action:

Methyl parathion was excluded from the list of active substances authorized for use in plant protection products in 1991 under the Law on protection of plants against pests and blights. It has prohibited to production, use and place on the market all plant protection products containing Methyl parathion according to annual adopted list of active ingredients banned for use in plant protection products under the lant Protection Act since 2003. Methyl parathion is designated as a PIC chemical. (Annex I of the Regulation on the import and export of certain dangerous chemicals on the Bulgarian territory). The import and use of the chemical for research or laboratory purposes in quantities less than 10 kg are allowed.

The reasons for the final regulatory action were relevant to: Human health and environment

Summary of known hazards and risks to human health:

Methyl parathion is highly toxic by inhalation and ingestion, and moderately toxic by dermal adsorption. Exposure to high doses of this chemical either by dermal contact or inhalation, can cause human fatality. When inhaled it can cause runny nose, coughing, chest discomfort, short breath, and wheezing due to constriction or excess fluid in the bronchial tubes.
Skin contact with this chemical can cause localized sweating and involuntary muscle contractions. Eye contact will cause pain, bleeding, tears, pupil constriction and blurred vision. Severe poisoning via any route will affect the central nervous system, producing incoordination, slurred speech, loss of reflexes, weakness, fatigue, involuntary muscle contractions, tremors of the tongue or eye lids, and eventually paralysis of the body extremities and the respiratory muscles. Other effects include involuntary defecation and urination, psychosis, irregular heart beats, unconsciousness, convulsions and coma. Death may be caused by respiratory failure or cardiac arrest.
Repeated or prolonged exposure to moderate levels (for example, among factory workers) may result to impaired memory and concentration, disorientation, severe depression, irritability, nightmares, sleepwalking and drowsiness or insomnia.
Factory workers who handle quantities of concentrated methyl parathion are at a high risk. Exposure to farm workers may occur during mixing, spraying or application of methyl parathion, during cleaning and repair of equipment or during re-entry into fields that have been sprayed.

Expected effect of the final regulatory action in relation to human health:

To avoid exposure of the chemicals and the associated risks to human health.

Summary of known hazards and risks to the environment:

Methyl parathion is not persistent in the environment. It is not bioconcentrated and is not transferred through food-chains and is degraded rapidly by many microorganisms and other forms of wildlife. It is only likely to cause damage to ecosystems in instances of heavy overexposure resulting from misuse or accidental spills. However, pollinators and other beneficial insects are at risk from spraying with methyl parathion.
The substance is very toxic to aquatic organisms. Special attention should be given to bees.

Expected effect of the final regulatory action in relation to the environment:

To avoid exposure of the chemical and the associated risks to environment.

Date of entry into force of the final regulatory action: 01/04/2003