Chemical name: Phosphorodithioic acid, S-[[(1,1-dimethylethyl)thio]methyl] O,O-diethyl ester

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:

Agricultural pesticides containing Terbufos molecule in any formulation are totally prohibited.

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

Summary of the final regulatory action:

Article 1.- Cancel all registrations of products containing the active ingredient TERBUFOS, in accordance with the provisions of literal f) of article 32 of CAN Decision 804, “Andean Standard for the Registration and Control of Chemical Pesticides for Agricultural Use in the Andean Community”.

Article 2.- Cancel all procedures that have been submitted to the Phytosanitary and Zoosanitary Regulation and Control Agency requesting the registration of products containing the active ingredient TERBUFOS.

Article 3.- Prohibit the importation of products containing the active ingredient TERBUFOS. Imports in the process of production, dispatch and/or transit that were authorized until July 19, 2024, may be nationalized during the validity of the permit.

Article 4.- Allow sale of products containing the active ingredient TERBUFOS, during the shelf life of the imported batch, printed on the product label.

Article 5.- Companies holding registrations for products containing the active ingredient TERBUFOS must submit a report on stocks and sales to the Phytosanitary and Zoosanitary Regulation and Control Agency by August 12, 2024. From this date, they will submit bi-monthly reports on sales and stocks of the same.

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

Summary of known hazards and risks to human health:

Terbufos is an organophosphate (OP) pesticide, this involves the inhibition of the enzyme acetylcholinesterase (AChE) by phosphorylation of the serine residue at the enzyme active site. This inhibition leads to the accumulation of acetylcholine and ultimately to neurotoxicity in the central and/or peripheral nervous system. For Terbufos, AChE inhibition is the most sensitive endpoint in the toxicological database across multiple species, duration, life stages and routes.

Terbufos is classified as "not likely to be carcinogenic to humans." Acute toxicity data for terbufos show that this chemical is extremely toxic. Terbufos is classified as Toxicity Category I by dermal route and was not classified for acute eye irritation because it caused 100% death in test animals within 24 hours. The skin sensitization study was not performed for terbufos due to its acute lethality.

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

Reduction of risks from the use of the highly hazardous pesticides (Ib HIGHLY HAZARDOUS).

Summary of known hazards and risks to the environment:

Ecological effects Effects on birds:

Terbufos is extremely toxic to birds. Its acute LD50 in Japanese quail is 28.6 mg/kg. Its LC50 is 143 to 157 ppm in quail. The LC50 reported in Japanese quail is 196 to 265 ppm in a 5-day study. No effects on bird reproduction have been demonstrated from chronic exposure to Terbufos.

Effects on aquatic organisms:

Terbufos is extremely toxic to fish and aquatic invertebrates. The LC50 in Daphnia magna and Gammarus psendogomnaens, freshwater invertebrates, is 0.00031 mg/l and 0.0002 mg/l respectively. The LC50 values for the technical material (88%) are 0.008 to 0.0013 mg/l in rainbow trout, 0.390 mg/l in fathead minnows and 0.0017 to 0.0024 mg/l in perch. The compound has a moderate potential to accumulate in the tissues of aquatic organisms.

Effects on other organisms:

Terbufos is expected to be extremely toxic to mammals and reptiles. It is not toxic to bees.

Breakdown in soils and groundwater:

Terbufos is low to moderately persistent in soils. It is rapidly converted to its metabolites which tend to persist in soil and are detected at harvest time. Terbufos and its metabolites degrade rapidly during the first 15 to 30 days after application, then gradually stabilize. Terbufos is generally immobile and therefore is not likely to leach and contaminate groundwater. Much of the chemical can be recovered near the application site. Being of low water solubility, Terbufos is not frequently found in groundwater. It has been found in a few groundwater samples collected at a few locations in the United States, at concentrations of approximately 0.01 mg/l.

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

Terbufos may cause environmental damage. Preventing the use of this chemical protects the environment and non-target organisms from the risks associated with exposure

Date of entry into force of the final regulatory action: 19/07/2024