Chlorpyrifos

Toxicity to birds

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

short-term toxicity to birds: acute oral toxicity test (LD50-only)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 71-1 (Avian Acute Oral Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Substance ID: TSN100726
Purity: 99.6%

Dose method:

capsule

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

other: Passer domesticus

Limit test:

no

Remarks:

Single oral dose

Post exposure observation period:

14 days

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

5

Control animals:

yes

Nominal and measured doses / concentrations:

~9.4, ~18.8, ~37.5, ~75.0, ~150, and ~300 mg a.i./kg

Reference substance (positive control):

no

Key result

Dose descriptor:

LD50

Effect level:

122 mg/kg bw

Conc. / dose based on:

act. ingr.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence intervals of 80 and 214 mg a.i./kg

Dose descriptor:

NOEL

Effect level:

9.4 mg/kg bw

Conc. / dose based on:

act. ingr.

Basis for effect:

signs of toxicity

Validity criteria fulfilled:

yes

Conclusions:

LD50 (Sparrow): ~122 mg a.i./kg

Executive summary:

The study was conducted following FIFRA guideline 71-1. The test substance was tested for acute oral toxicity to wild house sparrows, Passer domesticus. Seventy house sparrows (5 males and 5 females per treatment group) were administered test substance as a single encapsulated dose at nominal concentrations of 0, ~9.4, ~18.8, ~37.5, ~75.0, ~150, and ~300 mg active ingredient (a.i.)/kg of body weight and were observed for 14 days. Dosages were based on an approximate body weight of 25 grams per bird and were not adjusted for individual body weight.

There was no mortality in the control, ~9.4 and ~18.8 mg a.i./kg treatment groups. However, there was 10% and 40% mortality in the ~37.5 and ~75.0 mg a.i./kg treatment groups, respectively; and, 70% mortality occurred in the ~150 and ~300 mg a.i./kg treatment levels. Sublethal effects were concentration dependent and were noted in all treatment levels. Surviving birds in the ~9.4, ~18.8, and ~37.5 mg a.i./kg treatment groups were normal in appearance and behavior by day 1, while surviving birds in the ~75 mg a.i./kg treatment level were normal in appearance and behavior by day 2. Birds in the ~150 and ~300 mg a.i./kg treatment group that survived were normal in appearance and behavior by test day 3. There was no change in body weight between the control birds and birds surviving treatment. Based upon the transient signs of toxicity at the ~9.4 mg a.i./kg treatment level, the no-observed-effect level (NOEL) was below ~9.4 mg a.i./kg. The acute oral LD50 was ~122 mg a.i./kg, with a 95% confidence interval of ~80-214 mg a.i./kg. According to an EPA classification system, test substance is moderately toxic to the house sparrow.

Reference 2

Endpoint:

short-term toxicity to birds: acute oral toxicity test (LD50-slope)

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 223 (Avian Acute Oral Toxicity Test)

Deviations:

no

GLP compliance:

yes

Specific details on test material used for the study:

Lot Number: 7299412
Purity: 97.6%

Dose method:

gavage

Analytical monitoring:

no

Vehicle:

yes

Remarks:

1% w/v aqueous methyl cellulose

Test organisms (species):

Colinus virginianus

Limit test:

no

Remarks:

Single oral dose

Post exposure observation period:

14 days

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

Stage 1 and 2: One bird per dose
Stage 3: Two birds per dose
Control: 5 birds

Control animals:

yes, concurrent vehicle

Nominal and measured doses / concentrations:

Stage 1: 2.54, 13, 48 and 177 mg/kg
Stage 2: 8.56, 10.9, 13.8, 17.5, 22.2, 28.1, 35.7, 45.3, 57.5 and 72.9 mg/kg
Stage 3 and 3b: 25, 31.7, 40.2, 51 and 64.8 mg/kg

Reference substance (positive control):

no

Key result

Dose descriptor:

LD50

Effect level:

53.34 mg/kg bw

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence intervals of 39.24 and 169.37 mg/kg

Validity criteria fulfilled:

yes

Conclusions:

LD50 (Quail): 53.34 mg/kg bw (with a slope of 8.53)

Executive summary:

The study was designed to determine the acute oral toxicity (LD50) of the test substance to the Bobwhite Quail. The study was conducted in compliance with the methods described in the test guideline OECD 223.

Testing was conducted in three stages. A further five birds were included as a control group, and were dosed with equivalent volumes of vehicle (1% aqueous methyl cellulose) only. LD50 was likely to be lower than the Limit dose of 2000 mg/kg therefore a limit test was not performed.

In Stage 1, one bird was dosed at each of four dose levels: 2.54, 13, 48 and 177 mg/kg. In stage 2, one bird was dosed at each of ten dose levels: 8.56, 10.9, 13.8, 17.5, 22.2, 28.1, 35.7, 45.3, 57.5 and 72.9 mg/kg. In the third and final stage (Stage 3b), two birds were dosed at each of five dose levels: 25, 31.7, 40.2, 51 and 64.8 mg/kg.

In all stages, birds were observed for 14 days following dosing. Observations included mortality, clinical signs, bodyweight, food consumption and post mortem examination.

All mortality occurred at doses of 45.3 mg/kg and above. Calculations from the cumulative mortality data resulted in an LD50 value of 53.34 mg/kg (95% confidence intervals 39.24, 169.37 mg/kg) with a slope of 8.53 (95% confidence intervals 0.636, 16.432).

Clinical signs of toxicity included subdued behaviour (45.3 mg/kg) and unsteadiness of gait (45.30, 31.7, 57.50 and 64.8 mg/kg). Marked reductions in bodyweight were seen for birds dosed at stage 2 and 3. When compared to the control group food consumption in most test animals was reduced during Day 1 to 3. In surviving birds, there was evidence of recovery in terms of clinical signs and bodyweight consumption during the latter part of the observation period. Findings at necropsy, in a decedent bird, noted a food filled gizzard along with the upper part of the GI tract and the lower part was empty.

Under the conditions of this study, the acute oral LD50 value of the test substance to the Bobwhite Quail was found to be 53.34 mg/kg bodyweight, with 95% confidence intervals of 39.24 and 169.37 mg/kg.

Reference 3

Endpoint:

long-term toxicity to birds: reproduction test

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test substance was fed to mature Bobwhite quail at dietary concentrations of 25 ppm and 125 ppm throughout a one-generation reproduction study and the potential for reproductive impairment was evaluated.

GLP compliance:

no

Specific details on test material used for the study:

Lot Number: MM03257-1 AGR-155052
Purity: 96.8 ± 0.8%

Dose method:

feed

Analytical monitoring:

no

Vehicle:

yes

Remarks:

corn oil and diet

Test organisms (species):

Colinus virginianus

Limit test:

no

Total exposure duration (if not single dose):

17 wk

Remarks:

The birds were exposed to the treated diets 9 weeks prior to egg laying and 8 weeks during egg laying.

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

12 cocks, 24 hens per dose

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

25, 125 ppm

Reference substance (positive control):

no

Key result

Duration (if not single dose):

9 wk

Conc. / dose based on:

test mat.

Basis for effect:

reproductive parameters

Remarks on result:

other: Environmental levels of up to 125 ppm of the test substance did not represent a reproductive hazard to the Bobwhite quail.

Validity criteria fulfilled:

yes

Conclusions:

Environmental levels of up to 125 ppm of chlorpyrifos did not represent a reproductive hazard to the Bobwhite quail

Executive summary:

A one-generation reproduction study was conducted on adult bobwhite using 25 and 125 ppm concentrations of the test substance in their diets, respectively. The birds were exposed to the treated diets 9 weeks prior to egg laying and 8 weeks during egg laying.

Mature Bobwhite quail receiving the test substance at dietary concentrations of 25 ppm and 125 ppm showed no symptoms of toxicity or behavioral abnormalities for the duration of the study. Mortalities occurred as follows: Control group; no mortalities. 25 ppm group; one hen - week 12, one hen - week 13, one hen - week 14, one hen - week 15, two hens - week 17. 125 ppm group; one hen - week 9. With the exception of the single hen at the 125 ppm dose level, all mortalities occurred during the stress of egg production and, in all instances, no gross compound related abnormalities were noted upon necropsy; therefore these deaths were considered to be incidental and not compound related. With the exception of the above mentioned mortalities, all test and control quail appeared normal throughout the study.

Eggs laid, eggs cracked, viable embryos, live three week embryos, normal hatchlings, 14 day-old survivors, representative hatchlings body weight. representative 14 day-old survivors body weight, egg weight and eggshell thickness, demonstrate that the test substance caused no reproductive impairment at the dose levels tested.

Reference 4

Endpoint:

long-term toxicity to birds: reproduction test

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test substance was fed to mature Mallard ducks at dietary concentrations of 25 and 125 ppm throughout a one-generation reproduction study and the potential for reproductive impairment was evaluated.

GLP compliance:

no

Specific details on test material used for the study:

Lot Number: MM03257-1, AGR-155052
Purity: 96.8 ± 0.8%

Dose method:

feed

Analytical monitoring:

no

Vehicle:

yes

Remarks:

corn oil and diet

Test organisms (species):

Anas platyrhynchos

Limit test:

no

Total exposure duration (if not single dose):

17 wk

Remarks:

The birds were exposed to the treated diets 9 weeks prior to egg laying and 8 weeks during egg laying.

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

10 drakes, 25 hens per dose

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

25, 125 ppm

Reference substance (positive control):

no

Key result

Duration (if not single dose):

17 wk

Conc. / dose based on:

test mat.

Basis for effect:

reproductive parameters

Remarks on result:

other: Statistical significant impairment of reproductive success was evidenced at the 125 ppm dose level

Validity criteria fulfilled:

yes

Conclusions:

Environmental levels of up to 25 ppm of the test substance did not represent a reproductive hazard to the Mallard duck

Executive summary:

A one-generation reproduction study was conducted on adult Mallards using 25 and 125 ppm concentrations of the test substance in their diets, respectively. The birds were exposed to the treated diets 9 weeks prior to egg laying and 8 weeks during egg laying.

Birds treated at 25 ppm test substance showed no symptoms of toxicity or behavioral abnormalities. Mortalities occurred in eight of 35 adult birds (28%) treated at 125 ppm. A number of abnormalities in behavior and appearance occurred. Feed consumption was diminished during the first four weeks resulting in weight loss instead of gain.

Eggs laid, eggs cracked, viable embryos, live three-week embryos, normal hatchlings, 14 day-old survivors, representative hatchlings body weight, representative 14 day-old survivors body weight, egg weight and eggshell thickness demonstrate that the test substance, at the 25 ppm dose level caused no reproductive impairment. At the 125 ppm dose level statistically significant reproductive impairment was evidenced in the following parameters: eggs laid, viable embryos, live three week embryos, normal hatchlings, 14 day-old survivors, egg weight, eggshell thickness, body weight representative hatchlings, and body weight representative 14 day-old survivors.

Based on the results of this study, environmental levels of up to 25 ppm of the test substance do not represent a reproductive hazard to the Mallard duck.

Reference 5

Endpoint:

short-term toxicity to birds: dietary toxicity test

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The birds were exposed to the appropriate dietary concentrations for five days, and then maintained on toxicant-free diet for an additional three-day observation period. Symptoms of toxicity and mortality were recorded daily throughout the study.

GLP compliance:

no

Specific details on test material used for the study:

Lot Number: MM03257-1, AGR-155052

Dose method:

feed

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Corn oil and diet

Test organisms (species):

Colinus virginianus

Limit test:

no

Total exposure duration (if not single dose):

5 d

Post exposure observation period:

3 days

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

50 birds

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

Lab standard: 21.5, 31.6, 46.4, 68.2, 100 ppm
Experimental: 56.2, 100, 178, 316, 562 ppm

Reference substance (positive control):

no

Key result

Duration (if not single dose):

5 d

Dose descriptor:

LC50

Effect level:

423 other: ppm

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence intervals of 345 to 519 ppm

Validity criteria fulfilled:

yes

Conclusions:

LC50 (quail): 423 ppm

Executive summary:

The birds were exposed to the appropriate dietary concentrations for five days, and then maintained on toxicant-free diet for an additional three-day observation period. Symptoms of toxicity and mortality were recorded daily throughout the study.

Laboratory standard: Symptoms of toxicity which preceded death at all dose levels included lethargy, followed by depression, reduced reaction to external stimuli (sound and movement), a ruffled appearance, wing droop, loss of coordination, prostrate posture, lower limb rigidity, and terminated in convulsions.

Experimental material: At the 56.2 ppm dose level one bird was noted as being toe picked on Day 7 and was found dead with lesions of the feet and legs typical of this form of cannibalism on Day 8. No other mortalities occurred at this dose level and no symptoms of toxicity were noted throughout the test period. Therefore. this mortality was not utilized in the statistical computations of the 8-day dietary LC50. At the 100 ppm dose level all birds were normal in appearance and behavior throughout the test period. At the 178 ppm dose level some hyperexcitibility was noted on Days 3 and 4 while lethargy became apparent on Day 5. and a few birds remained lethargic through Day 6. A slight reduction in body weight was noted at this dose level. Symptoms of toxicity preceding death at both the 316 ppm and 562 ppm dose levels included hyperexcitability, followed by lethargy, wing droop, loss of coordination, lower limb weakness, depression, reduced reaction to external stimuli (sound and movement), a ruffled appearance, prostrate posture, lower limb rigidity, and shallow and rapid respiration terminating in a comatose state prior to death. Surviving birds at all dose levels appeared normal by Day 7, though there was a marked reduction in body weight gain at the 316 ppm and 562 ppm dose levels. Necropsy of those birds which died during the course of the study revealed a partially empty to totally empty gastrointestinal tract, and one bird at the 562 ppm dose level exhibited a mottled liver. Autolysis rendered the necropsy of several of the birds which died during the course of the study meaningless. No abnormal lesions were noted upon necropsy of surviving birds at the termination of the study, though the birds at the 316 ppm and 562 ppm dose levels were notably smaller in size.

The acute LC50 of the test substance in the Bobwhite quail was 423 ppm, confidence limits 345 to 519 ppm.

Reference 6

Endpoint:

short-term toxicity to birds: dietary toxicity test

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The birds were exposed to the appropriate dietary concentrations for five days, and then maintained on toxicant-free diet for an additional three-day observation period. Symptoms of toxicity and mortality were recorded daily throughout the study.

GLP compliance:

no

Specific details on test material used for the study:

Lot Number: MM03257-1, AGR-155052

Dose method:

feed

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Corn oil and diet

Test organisms (species):

Anas platyrhynchos

Limit test:

no

Total exposure duration (if not single dose):

5 d

Post exposure observation period:

3 days

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

50 birds

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

Lab standard: 72, 100, 139, 193, and 269 ppm
Experimental: 56.2, 100, 178, 316, 562, and 1000 ppm

Reference substance (positive control):

no

Key result

Duration (if not single dose):

5 d

Dose descriptor:

LC50

Effect level:

591 other: ppm

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence intervals of 380 to 920 ppm

Validity criteria fulfilled:

yes

Conclusions:

LC50 (duck): 591 ppm

Executive summary:

The birds were exposed to the appropriate dietary concentrations for five days, and then maintained on toxicant-free diet for an additional three-day observation period. Symptoms of toxicity and mortality were recorded daily throughout the study.

Laboratory standard: Symptoms of toxicity preceding death at all dosage levels included lethargy, followed by depression, reduced reaction to external stimuli (sound and movement), wing droop loss of coordination, lower limb weakness, prostrate posture, loss of righting reflex, lower limb rigidity, minor muscle fasiculations, and colonic convulsions. Some hyperexcitability was noted at the 139 ppm dose level, and a reduction in body weight gain among survivors was noted at all dose levels.

Experimental: There was a 10% mortality rate at the 178 ppm dose level, a 30% mortality rate at the 316 ppm dose level and a 60% mortality rate at both the 562 ppm and 1000 ppm dose levels. All birds at the 56.2 ppm dose level appeared normal throughout the test period, while at the 100 ppm dose level a transient lethargy was noted on Day 6. At the 178 ppm and 316 ppm dose levels lethargy was the only toxic symptom noted. At the 562 and 1000 ppm dose levels lethargy, followed by depression, reduced reaction to external stimuli (sound and movement, loss of coordination, and lower limb weakness became apparent on Day 3, and survivors continued to exhibit these symptoms through Day 7.

The acute LC50 of the test substance in the Mallard duck was 591 ppm, confidence limits 380 to 920 ppm.

Reference 7

Endpoint:

short-term toxicity to birds: dietary toxicity test

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

The birds were exposed to the appropriate dietary concentrations for eleven days, and then maintained on toxicant-free diet for an additional five-day observation period. Symptoms of toxicity and mortality were recorded daily throughout the study.

GLP compliance:

no

Specific details on test material used for the study:

Lot Number: MM03257-1, AGR-155052

Dose method:

feed

Analytical monitoring:

no

Vehicle:

yes

Remarks:

Corn oil and diet

Test organisms (species):

Anas platyrhynchos

Limit test:

no

Total exposure duration (if not single dose):

11 d

Post exposure observation period:

5 days

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

50 birds

Control animals:

yes, plain diet

Nominal and measured doses / concentrations:

56.2,100,178, 316, and 562 ppm

Reference substance (positive control):

no

Key result

Duration (if not single dose):

11 d

Dose descriptor:

LC50

Effect level:

357 other: ppm

Conc. / dose based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95% confidence intervals of 293 to 436 ppm

Validity criteria fulfilled:

yes

Conclusions:

LC50 (duck): 357 ppm

Executive summary:

The birds were exposed to the appropriate dietary concentrations for eleven days, and then maintained on toxicant-free diet for an additional five-day observation period. Symptoms of toxicity and mortality were recorded daily throughout the study.

At the 56.2 ppm and 100 ppm dose levels no mortalities occurred, and no overt symptoms of toxicity were noted. There was a reduction in body weight gain at the 100 ppm dose level and a notable reduction in feed onsumption during the Day 1 to Day 6 period, with a slight reduction in feed consumption during the Day 6 to Day 11 period. At the 178 ppm dose level, some lethargy was evidenced on Day 10, there was a pronounced reduction in body weight gain, and feed consumption was lowered for the exposure period. Four mortalities occurred at the 316 ppm dose level, with the birds exhibiting symptoms of lethargy, followed by depression, reduced reaction to external stimuli (sound and movement), loss of coordination and ataxia, lower limb weakness and a ruffled appearance. Surviving birds gained an average of only 119 grams for the test period, as opposed to a negative control average body weight gain of 364 grams. Feed consumption was also lowered during the period of time the birds were exposed to treated feed. At the 562 ppm dose level, 9 mortalities occurred, with symptoms of toxicity evidenced prior to death including depression, reduced reaction to external stimuli (sound and movement), wing droop, loss of coordination, prostrate posture, loss of righting reflex, and lower limb rigidity. Feed consumption during the exposure period averaged 12 grams per bird per day as opposed to a negative control average of 89 grams per bird per day.

Necropsies of birds which died during the test period revealed partially to completely empty intestinal tracts with some areas of hyperemia and a general loss of body mass. No additional lesions other than those attributable to autolysis were noted, and no overt lesions were noted in those birds sacrificed at the termination of the study.

The acute LC50 of the test substance in the Mallard duck was 357 ppm, confidence limits 293 to 436 ppm.

Description of key information

Acute LD50 (Bobwhite quail): 53.34 mg/kg, OECD 223, Reliability = 1

Acute LD50 (Sparrow): ~122 mg /kg; EPA 81 -1; Reliability = 1

5 -day LC50 (Mallard duck): 591 ppm; no guideline followed; Reliability = 2

5 -day LC50 (Bobwhite quail): 423 ppm; no guideline followed; Reliability = 2

11 -day LC50 (Mallard duck): 357 ppm; no guideline followed; Reliability = 2

9-week NOEL for reproduction (Bobwhite quail): 125 ppm; no guideline followed; Reliability = 2

17 -week NOEL for reproduction (Mallard duck): 25 ppm, no guideline followed; Reliability - 2

Key value for chemical safety assessment

Short-term EC50 or LC50 for birds:

923 mg/kg food