Ametryn

Toxicity to birds

Description of key information

When tested according to the US Environmental Protection Agency Office of Pesticide Programs (EPA OPP) 71-4 (Avian Reproduction Test), the test substance was determined to possess a NOEC of 300 mg/kg diet for Bobwhite quail (Colinus virginianus) and Mallard duck (Anas platyrhynchos).
The value to be used for determination of the PNEC for birds is the NOEC of 300 mg/kg diet.

Key value for chemical safety assessment

Short-term EC50 or LC50 for birds:

850.6 mg/kg food

Long-term EC10, LC10 or NOEC for birds:

300 mg/kg food

Additional information

There are two acute oral studies; single direct exposure followed by a 14 day observation period. These tests provide a quantitative measurement of mortality which acts as a standard index of inherent toxicity.

 

Acute Oral toxicity to birds.001 - quail - 1997 – key: Acute oral toxicity to Japanese quail (Coturnix coturnix japonica) was assessed according to the methods defined by the Directive 96/12/EU of EC 8th March, 1996, Appendix – 1, 8.1 – Effect on the Birds, Method 8.1.1 Acute Oral Toxicity according to GLP. The study exposed 5 animals per sex per dose to the test substance by single oral doses, followed by an observation period of 14 days. Temperature was maintained at 23-27ºC with a relative humidity of 30-70% and a photoperiod of 12 hours light and 12 hours dark. Body weights were measured at the initiation of the study, on day 7, Day 14, and at death. The LD50 was determined to be 1040 mg/kg bw.

 

Acute Oral toxicity to birds.002 - bobwhite – 1988: Acute oral toxicity to Bobwhite quail (Colinus virginianus) was assessed according to the methods defined by the US Environmental Protection Agency Office of Pesticide Programs (EPA OPP) 71-1 (Avian Acute Oral Toxicity Test) according to GLP. The study exposed 5 animals per sex per dose to the test substance by single oral doses, followed by an observation period of 14 days. The LD50 was determined to be greater than 2250 mg/kg bw and the NOEC was determined to be 486 mg/kg bw based on signs of toxicity, body weight and feed consumption.

 

There are three dietary toxicity studies; short-term exposure in the diet for 5 days followed by a 3 day observation period. These tests provide a quantitative measurement of mortality. The Grimes and Jaber 1988 study with Bobwhite quail was selected as the key study as higher concentrations where tested.

 

Short-term dietary toxicity to birds.003 - bobwhite - 1988 - key: Short-term toxicity to Bobwhite quail (Colinus virginianus) was assessed according to the methods defined by US Environmental Protection Agency Office of Pesticide Programs (EPA OPP) 71-2 (Avian Dietary Toxicity Test) according to GLP in study lab by Grimes & Jaber. The study exposed 10 birds to dietary concentrations of the test substance for 5 days followed by an observation period of 3 days. Temperature was maintained at 37 ± 1ºC with a relative humidity of 41% and a photoperiod of 16 hours light and 8 hours dark. Birds were observed at least twice daily for mortality, signs of toxicity, or abnormal behaviour. Body weights were measured at initiation of the study, on Day 5, and at termination of the test on Day 8. Average estimated feed consumption was determined for each test concentration group and control for the exposure period. The LD50 was determined to be greater than 5620 ppm and the NOEC was determined to be 1780 ppm based on reduction in body weight gain at 3160 ppm.

 

Short-term dietary toxicity to birds.004 - quail - 1998: Short-term toxicity to Japanese quail (Coturnix coturnix japonica) was assessed according to OECD Guideline 205 (Avian Dietary Toxicity Test) according to GLP. The study exposed 10 birds to dietary concentrations of the test substance for 5 days followed by an observation period of 3 days. Temperature was maintained at 25 - 28ºC (except on four days during which the minimum temperature was 23ºC) with a relative humidity of 50-75% and a photoperiod of 12 hours light and 12 hours dark. Birds were observed for mortality twice on day 1 and once daily on days 5 and 8, clinical signs of toxicity once daily for 8 days, body weight on day 1 (before treatment), end of treatment (day 5) and at termination of the study (day 8), food consumption was determined as an average of the 1st to 5th days and 5th to 8th days (g/quail/day), and all chicks were necropsied at the end of the observation period. The short-term dietary NOEC is 5000 ppm which is equivalent to 850.6 mg/kg body weight/day.

 

Short-term dietary toxicity to birds.005 - mallard – 1988: Short-term toxicity to Mallard duck (Anas platyrhynchos) was assessed according to the methods defined by US Environmental Protection Agency Office of Pesticide Programs (EPA OPP) 71-2 (Avian Dietary Toxicity Test) according to GLP. The study exposed 10 birds to dietary concentrations of the test substance for 5 days followed by an observation period of 3 days. The LD50 was determined to be greater than 5620 ppm and the NOEC was determined to be less than 562 ppm based on body weight effects.

 

There are two reproductive toxicity studies; breeding birds are exposed via the diet to the test substance. These tests enable the identification of adverse effects on reproductive performance linked to gonadal functionality at exposure levels lower than those that cause serious parental toxicity. Bobwhite quail was selected as the key study as the NOEC for both studies was the same, but mallard’s are prone to regurgitation, whereas quail are not. Please note, the mallard study did not note that regurgitation was an issue for this specific study.

 

Reproductive toxicity to birds.006 - bobwhite - 1990 – key: Long-term toxicity to Bobwhite quail (Colinus virginianus) was assessed according to the methods defined by US Environmental Protection Agency Office of Pesticide Programs (EPA OPP) 71-4 (Avian Reproduction Test) according to GLP. The study exposed 16 breeding pairs of birds to dietary concentrations of the test substance for 21 weeks. Brooder temperature was maintained at 38ºC and study room temperature was maintained at 21.7 ± 2.1ºC with a relative humidity of 63 ± 15%. The photoperiod in the adult study room was maintained by a time clock. For the first 7 weeks of the test, animals were exposed to 8 hours of light per day. The photoperiod was increased during Week 8 to 17 hours of light per day and was maintained at that length until sacrifice of adult birds. Approximately 130 lux of illumination was provided throughout the study by fluorescent lights, which closely approximate noon-day sunlight. The photoperiod for the hatchlings was maintained by a time clock at 16 hours of light per day. Adult birds were observed at least once daily throughout the test for signs of toxicity or abnormal behaviour. All birds that died during the test were necropsied. As soon as practical after the death of the bird, the pen-mate was sacrificed and necropsied. Adult body weights were measured at study initiation, at the end of Weeks 2, 4, 6, and 8, and at terminal sacrifice. Body weights were not measured during egg-laying because of the possible adverse effects handling may have on egg production. Feed consumption was measured for each pen for a 7-day period every week. Feed consumption was determined by weighing the freshly-filled feeder on Day 0, recording the amount of any additional diet added during the week, and weighing the feed and remaining feed at the end of the 7-day period. No attempt was made to quantify the amount of feed wasted by the birds, as the wasted feed is normally scattered and mixed with water and excreta. The following parameters were examined per parental pen per week: eggs laid, eggs cracked, eggs broken, egg abnormalities, eggs set, eggshell thickness or eggshell strength, eggs fertile, embryos viable, normal hatchlings, abnormal hatchlings, clinical signs of toxicity, abnormalities and mortality, 14-day old surviving chicks, and chick body weight at hatching and 14 days after hatching. The long-term dietary NOEC is 300 mg/kg diet based on possible effects on adult body weight and reproductive parameters.

 

Reproductive toxicity to birds.007 - mallard - 1990: A long-term toxicity to Mallard duck (Anas platyrhynchos) was assessed according to the methods defined by US Environmental Protection Agency Office of Pesticide Programs (EPA OPP) 71-4 (Avian Reproduction Test) according to GLP. The study exposed 16 breeding pairs of birds to dietary concentrations of the test substance for 18 weeks. Test animals were observed for mortalities, signs of toxicity or abnormal behaviour, adult body weight and feed consumption, reproductive results, egg shell thickness, and offspring body weights. All birds that died during the test were necropsied. As soon as practical after the death of the bird, the pen-mate was sacrificed and necropsied. The pens in which adult mortality occurred were not used in statistical comparisons of the reproductive data. Each of the following parameters was analyzed statistically: adult body weight, adult feed consumption, eggs laid of maximum laid, eggs cracked of eggs laid, viable embryos of eggs set, live 3 -week embryos of viable embryos, hatchlings of 3 -week embryos, 14 -day old survivors of hatchlings, hatchlings of eggs set, 14 -day old survivors of eggs set, hatchlings of maximum set, 14 -day old survivors of maximum set, egg shell thickness, and offspring's body weight. The long-term dietary NOEC is 300 mg/kg diet based on possible effects on adult body weight and reproductive parameters.