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Brazil - Final Regulatory Action
Cyhexatin CAS number:
Date circular:

Chemical name: Tricyclohexyltin hydroxide

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 containing Cyhexatin and all uses of this active ingredient were prohibited in the end of the phase-out described below:
From June 12, 2009 until October 31, 2011:
- Exclude the use of cyhexatin in eggplant crops, coffee, strawberry and peach, maintaining authorized its use only in citrus crops.
- Only the use of stocks is allowed, restricted to So Paulo State.
- Reduce the Maximum Residue Food Limit (MRL).
From June 12, 2009:
- Dismiss the applications for new registration of products containing cyhexatin.
- Prohibit the import of technical product and formulations of cyhexatin.
From October 31, 2011 until April 30, 2012:
- Maintain the cyhexatin registration only for the purpose of monitoring pesticide residues in food.
From April 30, 2012: Cancel the registration of all products containing cyhexatin.

Pesticide use or uses that remain allowed:


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

Summary of the final regulatory action:

Gradual reduction in cyhexatin use until the ban of this pesticide.
*ban of use, sale, import and export.

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

Summary of known hazards and risks to human health:

Cyhexatin has high acute toxicity, (Class I - Highly Toxic - Brazil, 1992).
Studies conducted in mice, rats and rabbits by both oral and dermal routes of administration showed that cyhexatin is absorbed by the liver and kidney, causing serious hematological and liver abnormalities. In case of animals in gestation cyhexatin is absorbed by fetus tissue (fetotoxicity), revealing malformations and anomalies.
Teratology studies indicated that cyhexatin induces abortion (embryolethality) at very low doses. Several studies in rats and rabbits evidenced a higher incidence of hydrocephaly by different routes of administration. The severe embryo lethal effect and evidence of teratogenicity suggest that cyhexatin is not safe and may adversely affect embryo development and cause abortions and malformations.
Experiments suggested a high potential toxicity to eyes, causing irreversible corneal opacity, like other organotin compounds.
Dermal toxicity studies demonstrated dermal irritation producing erythema and edema, perceptible within 72 h after application, but there was no reversal even after 14 days of application.
Results of genotoxicity studies suggested that cyhexatin is not genotoxic. The long-term studies did not evidence carcinogenic potential of cyhexatin. Data are inadequate for an assessment of human carcinogenic potential.

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

Remove the human exposure to cyhexatin.

Date of entry into force of the final regulatory action: 12/06/2009