Esfenvalerate in freshwater and marine water

Toxicant default guideline values for protecting aquatic ecosystems

October 2000

Extracted from Section 8.3.7 ‘Detailed descriptions of chemicals’ of the ANZECC & ARMCANZ (2000) guidelines.

The default guideline values (previously known as ‘trigger values’) and associated information in this technical brief should be used in accordance with the detailed guidance provided in the Australian and New Zealand Guidelines for Fresh and Marine Water Quality.

Description of chemical

Esfenvalerate (CAS 66230-04-4) is a synthetic pyrethroid first introduced by Sumitomo Chemical Co. Ltd, and it has enhanced insecticidal activity over fenvalerate. Its IUPAC name is (S)-α-cyano-3-phenoxybenzyl-(S)-2-(4-chlorophenyl)-3-methylbutyrate. It has a molecular weight of 419.9 and its formula is C₂₅H₂₂ClNO₃. It has very low solubility in water, to 2 µg/L at 25°C and high log K_ow of 6.22 at 25°C (Tomlin 1994). The current analytical practical quantitation limit (PQL) for esfenvalerate in water is 0.5 µg/L (NSW EPA 2000).

Uses and environmental fate

Esfenvalerate is an insecticide that acts by ingestion and contact on a broad range of insect pests of fruit, vegetables, cotton and other crops (Tomlin 1994). Esfenvalerate, like many pyrethroids, binds strongly to clay and organic matter and it has a K_oc of 5300.

Aquatic toxicology

Freshwater fish: three species, 48 to 96-hour LC50, 0.07 to 0.44 µg/L. Additional species Tilapia mossambica was less sensitive, 330 to 420 µg/L.

Chronic lowest observed effect concentration (LOEC), 90 days, Pimephales promelas of 0.028 µg/L.

Freshwater amphibians: two species, 48 to 96-hour LC50, 3.4 to 28.0 µg/L.

Freshwater crustaceans: one species, LC50, Daphnia magna, 0.27 µg/L. Three species, chronic data: 21-day LOEC, copepod, 0.15 µg/L; 42-day LOEC cladoceran, 0.15 µg/L; 42-day LOEC Hyalella azteca, 0.05 µg/L.

Freshwater algae: no suitable data available.

Freshwater mesocosms: Two pond multiple species studies fully satisfied Organisation for Economic Co-operation and Development (OECD) requirements (Fairchild et al. 1992, Webber et al. 1992) and a further pond study had two replicates of treatments (Lozano et al. 1992). No observed effect concentration (NOEC) values were 0.01 µg/L (x 4), 0.18, 0.2 and 0.25 µg/L. These were used for guideline derivation but the resultant high reliability trigger value can not be adjusted for different protection levels. The trigger value from the mesocosm data is the same as that derived by applying an assessment factor (AF) of 20 to the lowest chronic data.

No marine data were available.

Australian and New Zealand data

Australian laboratory data indicate that even very short-term pulse exposures to the fish Melanotaenia fluviatilis (Holdway et al. 1994), less than 1.5 hours, can result in delayed mortality (LC50) at concentrations as low as 0.09 µg/L. Other studies on Daphnia carinata (Barry et al. 1995b) were oriented to studying the effect of food and data could not be readily used for deriving guidelines.

Factors causing variations in toxicity

The low water solubility and high log K_ow indicate that esfenvalerate would be strongly bound to sediment or suspended matter and would be transient in the water column. Results of pond studies would take this into account.

Guidelines

A high reliability freshwater trigger value of 0.001 µg/L was derived for esfenvalerate by applying a factor of 10 to the lowest multiple species NOEC of 0.01 µg/L. This figure cannot be adjusted for different protection levels but there are insufficient data to use the statistical distribution approach. In the absence of marine data, this could be adopted as a marine low reliability trigger value, for use only as an indicative interim working level.

References

ANZECC & ARMCANZ 2000. Australian and New Zealand Guidelines for Fresh and Marine Water Quality, Australian and New Zealand Environment and Conservation Council and Agriculture and Resource Management Council of Australia and New Zealand, Canberra.

Barry MJ, Logan DC, Ahokas JT & Holdway DA 1995b. An effect of algal food concentration on toxicity of two agricultural pesticides to Daphnia carinata. Ecotoxicology and Environmental Safety 32, 273-279.

Fairchild JF, La Point TW, Zajicek JL, Nelson MK, Dwyer FJ & Lovely PA 1992. Population-community-and ecosystem-level responses of aquatic mesocosms to pulsed doses of a pyrethroid insecticide. Environmental Toxicology and Chemistry 111, 115–129.

Holdway DA, Barry MJ, Logan DC, Robertson D, Young V & Ahokas JT 1994. Toxicity of pulse-exposed fenvalerate and esfenvalerate to larval Australian crimson-spotted rainbow fish Melanotaenia fluviatilis. Aquatic Toxicology 28, 169–187.

Lozano SJ, O’Halloran SL, Sargent KW & Brazner JC 1992. Effects of esfenvalerate on aquatic organisms in littoral enclosures. Environmental Toxicology and Chemistry 11, 35–47.

NSW EPA 2000. Analytical Chemistry Section, Table of Trigger Values 20 March 2000, LD33/11, Lidcombe, NSW.

Tomlin C 1994. The pesticide manual: A world compendium. 10th edn, British Crop Protection Council & Royal Society of Chemistry, Bath, UK.

Webber EC, Deutsch WG, Bayne DR & Seesock WC 1992. Ecosystem-level testing of a synthetic pyrethroid insecticide in aquatic mesocosms. Environmental Toxicology and Chemistry 11, 87-105.