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Uruguay - Final Regulatory Action
Methyl parathion CAS number:
298-00-0
Date circular:
12/12/2008

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:

Prohibited all methyl-parathion formulations except microcapsules soluble in water and anticides powder formulations with active ingredient equal or less than 2%.

Pesticide use or uses that remain allowed:

Microcapsule formulations under the following conditions:
a)Use: only in fruit trees
b)Waiting time: 35 days
c)-Application: only on soils
d) Active ingredient concentration: max 45% (p/v)
Anticides power formulated with active ingredient equal or less than 2%

The final regulatory action was based on a risk or hazard evaluation: Yes

Summary of the final regulatory action:

Due to:
- high toxicity to humans and, particularly high risk to applicators;
- its toxicity implies, as well, high risks to beneficial insects and extreme toxicity for birds;
- despite its high toxicity, the risk can be significantly reduced by the use of microcapsule formulations;
- its short half life, rapid microbial degradation and the inability of bioconcentration, grant some advantages from an environmental point of view;
- for some of the permitted uses of methyl parathion, there are not substitutive products that meet the conditions of lower toxicity and equal efficacy, thus it is necessary maintaining the authorization of microcapsule formulations and specific uses;
- all formulations of this active ingredient, except microcapsules, are included in the FAO/UNEP PIC procedure.
Prohibited register and application of phytosanitary products based on methyl parathion for all agricultural use, except:
1 - Microcapsule formulations to be dissolved in water under the following conditions:
- Use: only in fruit trees
-Waiting time: 35 days
-Application: only on soils
- Active ingredient concentration: max 45% (p/v)
2 - Anticides power formulated with active ingredient equal or less than 2%

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

Summary of known hazards and risks to human health:

Was carried out considering the high toxicity of these products for humans and particularly, the high risk for appliers.

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

Restrict and reduce the use of products based on methyl parathion with the consequent reduction of risks to birds and beneficial insects.

Summary of known hazards and risks to the environment:

Due to high toxicity of methyl parathion formulations, their use means a high risk to birds and beneficial insects.

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

Restrict and reduce the use of plant protection products based on methyl parathion with the consequent reduction of the risks and harms to the environment.

Date of entry into force of the final regulatory action: 30/06/2002