2,6-dibromo-4-cyanophenyl octanoate

Toxicity to birds

Link to relevant study record(s)

Reference

Endpoint:

long-term toxicity to birds: reproduction test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 Oct, 1990 - 21 Aug, 1991

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 71-4 (Avian Reproduction Test)

Version / remarks:

1982

Deviations:

yes

Remarks:

According to the report: slight deviations in temperatures, humidity and light.

GLP compliance:

yes

Dose method:

feed

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

acetone

Details on preparation and analysis of diet:

Test diets were prepared by mixing test substance into a premix which was used for weekly preparation of the final diet. Control diet and three test concentrations were prepared weekly. Fresh diets were normally presented to the birds on Friday of each week and fresh-frozen diet were normally presented on Monday. Dietary concentrations were adjusted for purity of the test substance.
Two verification samples were collected from each test concentration on Day 0 of Weeks 1, 2, 3, 4, 8, 12, 16 and 20. Samples also were collected from the feeders on Day 7 of Weeks 1, 2, 3, 4, 8, 12, 16 and 20 to verify that the test substance was present throughout the feeding period. All samples were shipped immediately for analysis.
The concentration of test substance was determined by gas chromatography using an electron capture detector (GC/ECD).

Test organisms (species):

Anas platyrhynchos

Details on test organisms:

All birds were from the same hatch and were 22 weeks of age at test initiation. The birds were approaching their first breeding season and had not been used in previous testing. At test initiation all birds were healthy.
All test birds were acclimated to the caging and facilities for at least fourteen days prior to initiation of the study.

Limit test:

no

Total exposure duration (if not single dose):

21 wk

No. of animals per sex per dose and/or stage:

Each treatment and control group contained 32 birds divided into sixteen pairs (one male and one female).

Control animals:

yes, concurrent vehicle

Nominal and measured doses / concentrations:

Nominal concentrations: 35, 110 and 350 ppm a.i.
Mean measured concentrations: 37, 114 and 368 ppm a.i.

Details on test conditions:

The test birds were acclimated to the facilities for 5 weeks prior to initiation of the test. Birds did not receive any form of medication during acclimation. During acclimation and upon initiation of the test, the birds were maintained under a photoperiod of eight hours or less of light per day. At the beginning of Week 10, the photoperiod was increased to seventeen hours of light per day to induce egg laying. The photoperiod was maintained at 17 hours of light per day until adult sacrifice. The first eggs were set for incubation during Week 13.
The adult birds were housed indoors in batteries of pens measuring approximately 75X 90 X 45 cm high. The pens were constructed of galvanized wire grid and galvanized sheeting.
Each pen was equipped with a feeder and waterers.
Hatchlings were placed in batteries of brooding pens. Each pen measured approximately 62 X 92 X 25.5 cm high. The pens were constructed of vinyl coated wire mesh and stainless steel sheeting.

Details on examinations and observations:

All adult birds were observed at least once daily throughout the study for signs of toxicity or abnormal behavior. A record was maintained of all mortalities and observations.
Adult body weights were measured at test initiation, on Weeks 2, 4, 6, 8, and at terminal sacrifice.
Feed consumption is presented for each week of the study as grams of feed consumed per bird per day.

Details on reproductive parameters:

Records were maintained by pen for each of the following reproductive parameters:
- Eggs Laid
- Hatchlings
- Eggs Cracked
- Body Weight of Hatchlings
- Eggs Set
- 14-Day Old Survivors
- Viable Embryos
- Body Weight of 14-Day Old Survivors
- Live Three-Week Embryos
- Egg Shell Thickness

Reference substance (positive control):

no

Key result

Duration (if not single dose):

21 wk

Dose descriptor:

NOEC

Effect level:

ca. 110 mg/kg diet

Conc. / dose based on:

act. ingr.

Basis for effect:

reproductive parameters

Mortality and sub-lethal effects:

There were no treatment related mortalities at any of the concentrations tested. A single incidental mortality occurred in the 110 ppm a.i. treatment group. There were no mortalities in the control group or in the 35 or 350 ppm a.i. treatment group.
No overt signs of toxicity were observed at any of the concentrations tested.
All surviving adults were subjected to gross necropsy following terminal sacrifice. There were no apparent treatment related findings exhibited at the 35 ppm a.i. and 110 ppm a.i. test concentrations. At the 350 ppm a.i. test concentration there appeared to be a treatment related increase in the number of hens that displayed lesions of old egg yolk peritonitis or a regressing ovary. All other findings observed were considered to be incidental to treatment.
There were no apparent treatment related effects upon adult body weight at any of the concentrations tested.
There were no apparent treatment related effects upon feed consumption at the 35 and 110 ppm a.i. test concentrations. At the 350 ppm a.s. test concentration there appeared to be a slight increase in feed consumption during the period from Week 2 through Week 10 of the study that may have been treatment related.

Effects on reproduction:

There were no apparent treatment related effects upon reproductive parameters at the 35 ppm a.i. or 110 ppm a.i. test concentrations.
The reduction in egg production in the 350 ppm a.i. treatment group also was reflected in a slight reduction in the number of hatchlings and 14-day old survivors per hen.
There were no apparent treatment related effects upon egg shell thickness at any of the concentrations tested.
There were no apparent treatment related effects upon the body weight of hatchlings or 14-day old survivors at any of the concentrations tested.

Please refer to "overall remark/ attached background material" field for result tables.

Validity criteria fulfilled:

not specified

Remarks:

Validity criteria according to OECD 206 current guideline are fullfiled.

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, the NOEC 21 weeks for Anas patyrhynchos was 110 mg/kg diet, based on reproductive parameters.

Description of key information

The overall NOEC reproduction (21 weeks) for birds was estimated to be 110 mg a.i./kg diet for Anas platyrhynchos.

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for birds:

110 mg/kg food

Additional information

A key study (1991) investigating the chronic effects of test substance on bird species following EPA OPP 71-4 guideline, under GLP was available. The birds were exposed to the nominal dietary concentrations of 35, 100 and 350 mg a.i./kg feed. Mean measured concentrations were 37, 114 and 368 mg a.i./kg feed. Based on the nominal concentrations, after 21 weeks, no effects on the reproductive performance of Anas platyrhynchos were reported up to the 110 mg a.i./kg diet.

 

The first supportive study (1991) was conducted for 24 weeks according to the EPA OPP 71 -4 guideline and GLP with Colinus virginianus resulting in NOEC of 110 mg a.i./kg diet too.

 

The second supportive study (1973, non-GLP) was conducted for 28 days according to the EPA requirements with Colinus virginianus resulting in NOEC of > 5.28 mg a.i./kg diet.

 

The acute dietary toxicity of test substance on bird species has been investigated in two non-GLP supportives studies. The studies were conducted with standard species (Anas platyrhynchos and Colinus virginianus). The results from the 5 days-dietary tests were LC₅₀of 1315 and 2150 mg a.i./kg diet.

 

Additionally, birds mortality was evaluated in three acute oral tests, resulting in a LD₅₀ranging from 170 to 25350 mg /kg body weight after 14 to 21 days.