Nitrapyrin

Toxicity to birds

Description of key information

ACUTE ORAL

LD50 = 2708 mg/kg bw (mallard ducks), method similar to OECD 223 (gavage), Beavers (1978)

LD50 = 118 mg/kg bw (turkey poults); LD50 = 235 mg/kg bw (cockerel chicks), gelatin capsules, Stevenson (1968)

SHORT TERM TOXICITY

8-day LC50 = 1466 ppm (mallard ducks), 5 days in diet and 3 day recovery, Fink (1974)

8-day LC50 = 820 ppm (Japanese quail), 5 days in diet and 3 day recovery, Stevenson et al. (1968)

Key value for chemical safety assessment

Short-term EC50 or LC50 for birds:

820 mg/kg food

Additional information

There are a number of available study reports outlining the toxicity of the substance to birds. All of the studies pre-dated GLP and were not conducted to standardised guidelines. They were all, therefore, assigned a reliability score of 2 in line with the criteria of Klimisch et al. (1997).

In the first study by Beavers (1978), the acute toxicity of the test material to mallard ducks was investigated in a study which was conducted to a method similar to that which is outlined in the standardised guideline OECD 223. During the study, groups of 5 male and 5 female ducks received test material at dosage levels of 398, 631, 1000, 1590 or 2510 mg/kg bw by oral gavage; an additional group of 5 male and 5 female ducks received water only and served as controls. Body weights were recorded at study initiation and on days 3 and 7. Food consumption was recorded and signs of toxicity and mortality were recorded daily throughout the 14 day study period. Under the conditions of the study, the acute oral LD50 of the test material to mallard ducks was determined to be 2708 mg/kg bw.

Stevenson (1968) investigated the acute oral toxicity of the test material to Beltsville small white turkey poults and to White Leghorn cockerel chicks. During the study, groups of birds received a single administration of test material, in a gelatin capsule. Following administration, birds were observed for mortality and adverse effects for a two week period. Body weights were recorded at strategic intervals. Under the conditions of the study, the acute oral LD50 of the test material to turkey poults was determined to be 118 mg/kg bw; and the LD50 of the test material to Leghorn cockerels was determined to be 235 mg/kg bw.

In 1974, Fink investigated the short term toxicity of the test material to mallard ducks. During the study, the Mallard ducklings received dietary concentrations of test material of 0 (basal diet control), 215, 464, 1000, 2150 or 4640 ppm; the positive control group received dieldrin. The birds were exposed to appropriate dietary concentrations for five days, and then maintained on toxicant-free diet for an additional three day observation period. Body weights were recorded by pen at initiation and termination of the study. Food consumption was recorded by pen during the five-day exposure period. Symptoms of toxicity and mortality were recorded daily throughout the study. There was no mortality in the negative control groups; and the birds appeared normal for the duration of the study. The test material caused dose-related mortality, depressed body weight gain, and reduced food intake. There were no behavioural abnormalities associated with the exposure to the test material. In the positive control group, hyperexcitability followed by a period of depression were the only symptoms of toxicity preceding death at the 100 ppm dosage level. The following symptoms of toxicity were observed in the 159, 251, 398 and 631 ppm dosage levels and were dose-related in severity: ataxia, depression, loss of righting reflex, rigidly extended, legs, and salivation.

Under the conditions of the study the acute LC50 of the test material was determined to be 1466 ppm.

In 1968, Stevenson et al. investigated the short term dietary toxicity of the test material in a study which was conducted according to the methodology reported in the recommended protocol from the U.S. Fish and Wildlife Service, "Procedure for Evaluation of Acute Toxicity to Fish and Wildlife".

During the study, Japanese quail were fed test diets containing either test material, or the major metabolite of the test material. The study was conducted over 8 days, with birds in the positive control and test groups receiving the toxicant-containing diets during the first 5 days. Basal diets were fed during the final 3 days, when the birds were being held for observation. Feed consumption was measured for each time period. Body weights were by pen, all survivors were recorded as a group on experimental days -2, 0, 5 and 8. Mortality was recorded daily as well as daily observations for adverse effects.

Under the conditions of the study, the LC50 of the test material was determined to be 820 ppm following the short term dietary exposure to the test material over 8 days; the LC50 of the major metabolite of the test material was determined to be in excess of 5000 ppm following the short term dietary exposure to the test material over 8 days.