Chemical name: Phosphorothioic acid, O,O-diethyl O-(3,5,6-trichloro-2-pyridinyl) 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:

All formulations containing chlorpyrifos (active ingredients).

Pesticide use or uses that remain allowed:

None/Not applicable

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

Summary of the final regulatory action:

The Pesticide Technical & Advisory Committe e of Sri Lanka d uring its 28^th meeting on 7^th May 2004 decided to prohibit the residential indoor use of chlorpyrifos for termite controls in Sri Lanka, while other uses remained allowed. As a result of the above decision, all labels of registered chlorpyrifos products were amended to reflect the above decision.

The Pesticide Technical & Advisory Committee of Sri Lanka during its 65^th meeting on 05.04.2013 made a final regulatory action to ban chlorpyrifos in Sri Lanka. As a result of the decision, the registration of all products and formulations containing active ingredient chlorpyrifos was cancelled on 28 December 2016 (REF: Government Extraordinary Gazette No. 1999/33 dated 28.12 .2016 under the Control of Pesticides Act No.33 of 1980). Effective from that date, the use of chlorpyrifos as a pesticide for agriculture and structural termite controls were prohibited in Sri Lanka. Effective from the same date the production, trade and import of chlorpyrifos had all been prohibited.

[Dealers and farmers were given grace periods to finish off the old stock of chlorpyrifos products at the end of the following dates:

Cancellation of registration: 28 December 2016

Stock Clearance at dealers/shops: 28 December 2018

Use-up old stocks by farmers: No decision

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

Summary of known hazards and risks to human health:

The following study "Exposure and risk assessment for farmers occupationally exposed to chlorpyrifos" by Aponso et al., (2002) Annals of the Sri Lanka Department of Agriculture, 2002, 4: 233- 244 showed that farmers using chlorpyrifos on cucurbits (grows on trellises) can expose to unnecessary residue levels as measured by major metabolite, 3, 5, 6-t richloro- 2-pyridinol (TCP): results indicated that dermal exposure under normal use ranged from 4.8-19.6 microgram/cm2 on exposed skin; the elimination half-life of the urinary TCP metabolite was 31 .2 hr; the calculated hazard quotient of cholinesterase inhibition ranged fr om 0.8 -2.7, and margin of safety ranged from 3.6-14.3 for the farmer. This indicates the high occupational risk of chlorpyrifos to the farmer under use conditions. It was further revealed that the use of long- sleeved shirts had decrease the internal dose of chlorpyrifos (measured as TCP) than wearing short- sleeved shirts; the contrasting difference was that wearing long pants had increase the internal dose (may be due to prolonged exposure).

The following study "Analysis of water for pesticides in two major agricultural areas of the dry zone" by Aponso et al. (2003) Annals of the Sri Lanka Department of Agriculture, 2003, 5: 7-22 showed that the farming community in the study area was reported to have clinical symptoms of exposure by 83%, related to acute toxicity, but 21% of the group had confirmed effects related to pesticide exposure. The main symptoms found were dysuria, myalgia & headache.

The first review which was done by Pesticide Technical & Advisory Committee (PeTAC) at its 28^th meeting held on 07. 05.2004; based on the regulatory overview of the USEPA. (Human Health Risk Assessment Chlorpyrifos Phase 4, U.S. Environmental Protection Agency Office of Pesticide Programs Health Effects Division (7509C) Deborah C. Smegal, M.P.H., Risk Assessor, June 8, 2000). According to the report available exposure of chlorpyrifos by children has been mitigated as follows; the use on tomatoes, all indoor residential uses, all outdoor residential uses (except limited public health uses), all indoor non-residential uses were eliminated.

Accordingly, as a preliminary step, the PeTA C at it s 29^th meeting held on 12.07.2004 decided to prohibit indoor residential uses on termite control in Sri Lanka. All labelling was amended to reflect the above decision by 2004. During the progressive review of use, the PeTAC at its 30^th meeting held on 07.09.2004 decided to ban post-construction use as a termiticide while taking further attention to assess the risks associated for possible phase out from agriculture under the conditions of use by farmers.

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

Significant health risk reduction for farmers; being a high-volume pesticide, there will be significant reduction of chemicals & environmental load in consequent to this decision.

Summary of known hazards and risks to the environment:

The following study by Sumith et al. (2012) showed that chlorpyrifos, diazinon and carbosulfan had the greatest amount of agricultural application in the agricultural catchment, and chlorpyrifos, diazinon, and carbofuran were the dominant pollutants found. Chlorpyrifos and diazinon were detected in sediments at concentrations of 16.36 mg/kg (dry wt.). The study showed that 73% inhibition in muscle AChE activity in Garra ceylonensis was associated with intense pesticide exposure months. The AChE inhibition more than 70% in G. ceylonensis eyes in both Yala (76%) and Maha (72. 5%) seasons indicates particular sensitivity of eye tissue to inhibitors. The less dramatic AChE inhibition in the eye tissues in Devario malabaricus and Rasbora daniconius in both seasons indicates exemplary protective capacity of muscle AChE in fish. The highest inhibition of AChE (up to 60% in brain and up to 56% in muscle AChE activity in R. daniconius and up to 47.8% in brain and up to 64.6% in muscle AChE activity in D. malabaricus) occurred during the intense pesticide exposure months.

This study revealed dynamic impact of agricultural pollutants (including chlorpyrifos) on indigenous fish communities & their existence.

Ref . Sumith et al. (2012). SEASONAL EXPOSURE OF FISH TO NEUROTOXIC PESTICIDES IN AN INTENSIVE AGRICULTURAL CATCHMENT, UMA-OYA, SRI LANKA: LINKING CONTAMINATION AND ACETYLCHOLINE -STERASE INHIBITION. Environmental Toxicology and Chemistry, 31 (7), 1 501-1 51 0, 2012.

(risk assessment 2)

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

Less chemical burden to the environment.

Date of entry into force of the final regulatory action: 28/12/2016

Ban of registration by the Government Extraordinary Gazette No. 1999/33 dated 28.12.2016 under the Control of Pesticides Act No.33 of 1980.