2,6-dibromo-4-cyanophenyl heptanoate

Toxicity to birds

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to birds: dietary toxicity test

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 Jun - 02 Jul, 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 205 (Avian Dietary Toxicity Test)

Version / remarks:

1984

Deviations:

not specified

GLP compliance:

yes

Dose method:

homogenously mixed into feed (accounts for technical substances)

Analytical monitoring:

yes

Vehicle:

yes

Remarks:

acetone

Details on preparation and analysis of diet:

The test substance bottle was placed in a hot water bath to liquify.
The test diets were prepared by first dissolving/suspending the test substance in acetone and corn oil, then blending the solution into the diet in a mixer. The concentration of com oil in the treated diets was 2 %. Acetone was allowed to volatilize from the diets during the mixing procedure.
The control diet was prepared by weighing the basal ration and adding acetone, (100 mL), corn oil (65 mL) and blending all constituents for approximately 10 minutes.

Samples of the test diets were taken, frozen and transferred to laboartory for analysis.
A portion of the avian feed was extracted, centrifugated and diluated. The concentration of active susbtance was determined by gas chromatography using an electron capture detector (GC/F.CD).

Test organisms (species):

Colinus virginianus

Details on test organisms:

The test animals were 10 days of age at test initiation and were originated from in-house laboratory.
Throughout acclimation and testing all test birds were fed a game bird ration formulated by the laboratory. The chicks were given a vitamin supplement in their water from the day they were hatched until the initiation of the test. Public water and feed were provided ad libitum during acclimation and during the test. The birds received no form of antibiotic medication during acclimation or the test.

Limit test:

no

Total exposure duration (if not single dose):

5 d

Post exposure observation period:

3 additional days of observation.

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

Birds were assigned to five test groups and four control groups. Each treatment or control group contained ten chicks.

Control animals:

yes

Nominal and measured doses / concentrations:

Nominal concentrations: 316, 562, 1000, 1780, 3160 and 5620 mg/kg diet
Nominal dietary doses: 88, 157, 323, 601, 1264 and 2498 mg/kg bw/d.
Measured concentrations: 316, 562, 1000, 1780, 3160 and 5620 ppm (82 %, 99 %, 95 %, 100 %, 97 %, and 88 % of the day 0 concentrations)

Details on test conditions:

Birds were assigned to pens by indiscriminate draw.

Each pen had floor space that measured approximately 72 X 90 cm.
Ceiling height was approximately 23 cm.
External walls, ceilings and floors were constructed of galvanized steel wire and sheeting.
Each group of birds was identified by pen number.

During the test the average temperature in the brooding compartment of the pens was 37 °C ± 1 °C (SD). Average ambient room temperature for this study was 28.1 °C ± 1.1 °C (SD) with an average relative humidity of 58 % ± 11 % (SD). The photoperiod was sixteen hours of light per day during acclimation and throughout the test. The light source was fluorescent lights (noon-day sun). The birds were exposed to an average of approximately 408 lux of illumination.

Details on examinations and observations:

During acclimation all birds were observed daily. Birds exhibiting abnormal behavior or physical injury were not used. Following test initiation and continuing until termination, all birds were observed at least twice daily. A record was maintained of all mortality, signs of toxicity and abnormal behavior.
Body weights by group were measured at the initiation of the test, on day 5, and at termination of the test on day 8. Average feed consumption values were measured daily during the exposure period (days 0-1, 1-2, 2-3, 3-4 and 4-5) and during the post exposure observation period (days 6-8) for each treatment and control group.

Details on reproductive parameters:

no

Reference substance (positive control):

no

Key result

Duration (if not single dose):

5 d

Dose descriptor:

LC50

Effect level:

4 525 mg/kg diet

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Key result

Duration (if not single dose):

5 d

Dose descriptor:

LD50

Effect level:

1 902 mg/kg bw/day

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Key result

Duration (if not single dose):

5 d

Dose descriptor:

NOEC

Effect level:

1 000 mg/kg diet

Conc. / dose based on:

test mat.

Basis for effect:

body weight

Repellency factors (if applicable):

Not specified

Mortality and sub-lethal effects:

There were no mortalities in any of the control replicates. One bird in one of the control replicates was noted with a ventral head curl on days 7 and 8. Otherwise, all birds in the control replicates were normal in appearance and behavior throughout the test period.

Throughout the test period, there were no mortalities in the 316, 562, 1000 or the 1780 ppm test concentrations. However, there was 20 % mortality (2 of 10) at the 3160 ppm test concentration, and 70 % mortality (7 of 10) at the 5620 ppm test concentration. There were no overt signs of toxicity in the 316, 562, 1000 or 1780 ppm treatment groups. All birds at these test concentrations were normal in appearance and behavior throughout the study period.

At the 3160 ppm test concentration signs of toxicity were first noted on the morning of day 2, at which time the first mortality was also noted. The second mortality at this test concentration was noted on the afternoon of day 2. Signs of toxicity persisted through the morning of day 6, after which all remaining birds were noted as normal in appearance and behavior until test termination.

Signs of toxicity at the 5620 ppm test concentration were first noted on the morning of day 2, at which time the first mortality was also noted. Four birds were found dead on day 3 and single mortalities were each noted on days 4 and 5. Signs of toxicity continued to be exhibited through the afternoon of day 6. From the morning of day 7 until test termination, all remaining birds at this test concentration were noted as normal in appearance and behavior.

Signs of toxicity characteristic of intoxication with test substance were depression, reduced reaction to external stimuli, wing droop, a ruffled appearance, and lower limb weakness.

When compared to the controls, there was a slight reduction in body weight gain among birds at the 1780 ppm test concentration during the exposure period (days 0-5). During the same time period, birds as a group at the 3160 ppm test concentration did not exhibit any gain in weight, while birds at the 5620 ppm test concentration exhibited a loss in body weight. Birds at the 5620 ppm test concentration displayed a slight reduction in feed consumption during the first day of exposure to treated diet.

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

Table 1: Validity criteria for OECD 205 (1984)

Criterion	Outcome	Criterion fulfilled
Mortality in the control < 10 % at the end of the test.	0 %	Yes
The lowest treatment level should not result in compound-related mortality or other observable toxic effects	Normal in appearance/behavior and no mortality up to 1780 ppm	Yes
There must be evidence that the concentration of the substance being tested has been satisfactorily maintained in the diet (it should be at least 80 % of the nominal concentration) throughout the test period.	The mean measured concentrations ranged from 82 to 100 %	Yes

Validity criteria fulfilled:

yes

Remarks:

not specified in the report, for further details please refer to “Any other information on results incl. tables”.

Conclusions:

The present guideline study was conducted in compliance with GLP. Under the test conditions used, the 5-day LC50 for Colinus virginianus was 4525 mg/kg diet, which is equivalent to a LDD50 of 1902 mg/kg bw/day based on actual consummed diet.

Description of key information

The LD₅₀ and NOEC (5 days) for birds were estimated to be 1902 mg/kg body weight/d and 1000 mg/kg diet, respectively for C. virginianus.

Key value for chemical safety assessment

Short-term EC50 or LC50 for birds:

1 902 mg/kg bw/day

Long-term EC10, LC10 or NOEC for birds:

1 000 mg/kg food

Additional information

A key study (1991) investigating the acute dietary toxicity of test substance on bird species following OECD 205 guideline, under GLP was available. The birds were exposed to the nominal dietary concentrations of 88, 157, 323, 601, 1264 and 2498 mg/kg bw/d (equivalent to nominal concentrations of 316, 562, 1000, 1780, 3160 and 5620 mg a.i./kg feed). Based on the nominal concentrations, after 5-day exposure, the LC₅₀, LD₅₀ and NOEC were 4525 mg/kg diet, 1902 mg/kg bw/d and 1000 mg/kg diet, respectively.

 

Additionally, birds ‘mortality was evaluated in an acute oral test according to EPA OPP 71-1 guideline, resulting in a LD₅₀ of 379 mg /kg body weight after 14 days.