Captan

Endpoint summary

Description of key information

1. Subchronic (90-day) study inhalation (nose only), rat ALpk:APfSD (Wistar derived) m/f, USEPA Guideline 82-4; method B.29 of Regulation (EC) No 440/2008, Repeated Dose (90 Days) Toxicity (Inhalation): NOEC: 0.60 mg/L

2. Chronic Toxicity (52 weeks) oral feed, beagle dogs m/f, (USEPA Guideline 83-1 (Chronic Toxicity)), Repeated dose (one dose daily/52 weeks), Toxicity (oral): NOEL: 300 mg/kg bw/day (m/f)

3. Subacute (21-day) study dermal (occlusive), rabbit (New Zealand White) m/f, (USEPA Guideline 83-1. (Repeated Dose (21 Days) Toxicity (Dermal): NOEL: 110 mg/kg bw/day (m/f) systemic effects, NOEL: 12.5 mg/kg bw (m/f) local effects

Key value for chemical safety assessment

Toxic effect type:

concentration-driven

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

24 October 1986 to 3 December 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPP 83-1 (Chronic Toxicity)

Deviations:

no

GLP compliance:

yes

Limit test:

yes

Species:

dog

Strain:

Beagle

Sex:

male/female

Route of administration:

oral: capsule

Vehicle:

unchanged (no vehicle)

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

52 weeks (one year)

Frequency of treatment:

once/day

Dose / conc.:

12.5 mg/kg bw/day (actual dose received)

Dose / conc.:

60 mg/kg bw/day (actual dose received)

Dose / conc.:

300 mg/kg bw/day (actual dose received)

No. of animals per sex per dose:

Three groups: 12.5, 60 and 300 mg/kg bw/day (5/sex/dose). Control group: empty gelatine capsules (5/sex).

Control animals:

yes, concurrent no treatment

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
DETAILED CLINICAL OBSERVATIONS: Yes
BODY WEIGHT: Yes
FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: Yes
OPHTHALMOSCOPIC EXAMINATION: Yes
HAEMATOLOGY: Yes
CLINICAL CHEMISTRY: Yes
URINALYSIS: Yes

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Key result

Dose descriptor:

NOEL

Effect level:

300 mg/kg bw/day (actual dose received)

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: Captan Technical was well tolerated by dogs when administered orally in gelatin capsules at dose levels up to 300 mg/kg/day for 52 weeks.

Critical effects observed:

not specified

 

Captan Technical was administered orally by capsule to beagle dogs at dosage levels of 12.5, 60.0 and 300.0 mg/kg/day for 52 weeks. Control dogs received empty gelatin capsules. Five male and five female animals were initiated on study in each of the four groups.

All animals survived until the termination of the study. The 300 mg/kg/day dosage level had a higher incidence of emesis and soft/mucoid stool compared to those of the control group. These observations were considered to be related to administration of the test substance.

One female at the 60 mg/kg/day dosage was noted with observation "appears to have convulsed" on three days during the study. Convulsions have been observed spontaneously in dogs at IRDC although at a low incidence. Microscopically all tissues for this animal were within normal limits. Since the finding was observed rarely, and only in one mid-dose animal, it was not considered to be related to administration of the test article.

General observations: There were no mortalities during the study. A higher incidence of emesis and soft/mucoid stool was sporadically noted in 300 mg/kg bw/day animals compared to the control, although these were also noted in other groups including controls. This was probably a treatment-related effect but was not considered as a toxicological effect.

There were no significant differences in group mean body weight at any interval. Food consumption values for females administered test substance appeared lower than control females. However, food consumption in the control group females was considered higher than normal and therefore no toxicological significance is attached to the relatively low food consumption in the 60 and 300 mg/kg bw/day animals. No treatment-related

ophthalmological abnormalities were detected. Physical examination findings revealed no significant findings.

 

Haematology, clinical chemistry and urinalysis: There were no treatment-related effects on haematological or clinical chemistry parameters and urinalysis was considered normal.

 

Gross pathology, organ weights and histopathology: No treatment-related gross pathological changes were observed. Absolute organ weights were unaffected by treatment. A significant increase in the liver weight was observed in 300 mg/kg bw/day males compared to the control. This was considered to be related to the lower body weight observed in this group compared to the control and not treatment-related. No treatment-related histopathological changes were observed.

 

 

Table 7.5.1-1: Group mean body weight at study week 52 and the percent differences from the pretest

Dosage Level (mg/kg/day)	Mean Body Weights, kg, Week 52 (percent difference from pretest)
	Male			Female
	Pretest	Week 52	% difference	Pretest	Week 52	% difference
0.0	12.2	13.3	+9.0	9.0	9.4	+4.4
12.5	11.7	12.9	+10.3	9.3	10.1	+8.6
60.0	11.1	11.8	+6.3	9.3	10.8	+16.1
300	11.7	12.6	+7.7	9.4	10.00	+6.4

 

Table 7.5.1-2: Average group mean food consumption g/animal/day for study weeks 1 through 52 and the percent difference from the control group

Dosage Level (mg/kg/day)	Average Group Mean Food Consumption, g/animal/day (percent difference from control)
	Male		Female
		% difference		% difference
0.0	389		408
12.5	417	+7.2	311	-23.8
60.0	441	+13.4	316	-22.5
300.0	413	+6.2	351	-14.0

 

Table 7.5.1-3-: Average group mean food consumption g/kg/day for study weeks 1 through 52 and the percent difference from the control group

Dosage Level (mg/kg/day)	Average Group Mean Food Consumption, g/kg/day (percent difference from control)
	Male		Female
		% difference		% difference
0.0	30.1		44.4
12.5	33.8	+ 12.3	31.5	-29.1
60.0	38.0	+26.2	32.1	-27.7
300.0	34.5	+14.6	36.5	-17.8

Conclusions:

The NOEL was 300 mg/kg bw/day in both male and female dogs.

Executive summary:

Captan Technical was administered orally by capsule to beagle dogs at dosage levels of 12.5, 60.0 and 300.0 mg/kg/day for 52 weeks; control dogs received empty gelatin capsules. The dose levels for this study were selected on the basis of a preliminary four week range finding study in dogs in which dose levels of 300 mg/kg/day and above produced emesis, in appetence and a reduction in body weight.

Computerized random selection in a block design based on body weights. Animals with large absolute differences from the quarantine population body weight mean eliminated prior to randomization and homogeneity of group body weight variances used as the criteria for acceptance. Body weights, food consumption values, clinical pathology parameters and organ weight values analyzed using analysis of variance and Bartlett's test. Treatment groups compared to the control group, by sex, using the appropriate t-statistic (equal or unequal variance). Nonparametric analysis, when appropriate, by rank transformation.

Observations noted for dogs in the 12.5 mg/kg/day group were similar to those recorded for the control group. Body weight gains were similar in all groups. Food consumption values in male groups were comparable through the study. Food consumption values in female dogs administered the test substance appeared to be less than those for control females. However, food consumption values for the female control group were higher than normal. Food consumption for all female dogs exposed to the test substance was considered normal at around 300 to 350 g/dog/day. Consequently no toxicological significance was attributed to the apparent reduction in food consumption in test substance treated animals.

Other observations and examinations performed during the in-life phase of the study were unremarkable. No test substance related abnormalities were detected during the ophthalmoscopic examinations, detailed physical examinations, and the clinical pathology evaluations.

No test article related macroscopic changes were observed in any of the male or female dogs that were terminally sacrificed after a one year period of study. Occasional changes that were seen at necropsy in these dogs were considered incidental in nature and unrelated to the administration of the test article.

At terminal sacrifice, no test article related organ weight changes were observed in any of the treatment groups.

There were no test article related microscopic changes in any of the male or female dogs that were sacrificed after a one year period of study. Occasional changes were seen in a variety of organs, but these were considered spontaneous in nature and usual for dogs of this age and breed.

In conclusion Captan Technical was well tolerated by dogs when administered orally in gelatin capsules at dosage levels up to 300 mg/kg/day for 52 weeks. There was some emesis and soft/mucoid stool at the 300 mg/kg/day level. However, these signs were regarded as a response to the taste and physical nature of the test substance rather than a toxicological effect. The no toxic effect dose level in this study was 300 mg of Captan Technical/kg/day to both male and female dogs. Daily dosage of higher than 300 mg/kg was considered likely to result in significant toxicity and potentially lead to deaths in a one year study.

The NOEL for oral administration of captan is set to 300 mg/kg bw/day in both male and female dogs.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

300 mg/kg bw/day

Study duration:

chronic

Species:

dog

Repeated dose toxicity: inhalation - systemic effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 October 1988 to 19 January 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.29 (Sub-Chronic Inhalation Toxicity:90-Day Study)

Deviations:

yes

Remarks:

Temperature and humidity levels were occasionally outside nominal range. One male and one female (both 12.98 μg/L) were returned to the wrong holding cage, resulting in pregnancy. The pregnant animal was subsequently terminated.

Qualifier:

according to guideline

Guideline:

EPA OPP 82-4 (90-Day Inhalation Toxicity)

Deviations:

yes

Remarks:

Temperature and humidity levels were occasionally outside nominal range. One male and one female (both 12.98 μg/L) were returned to the wrong holding cage, resulting in pregnancy. The pregnant animal was subsequently terminated.

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- groups of 40 male and 40 female specific pathogen free, A1pk:APfSD (Wistar derived), albino rats
- Source: Barriered Animal Breeding Unit (BABU) Alderley Park. Cheshire. UK
- age: five to six weeks
- free access to mains drinking water and food, except during exposure periods when all food and water was removed.
- room temperature: 20-24°C
- relative humidity: 40-60%

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

Animals were exposed nose-only in restraining tubes supplied by Battelle, Geneva. Switzerland, which were Inserted into an ICl designed PERSPEX exposure chamber having an internal volume of approximately 46 litres. Animals were placed in the exposure chambers in replicate order with male and females on separate levels. Their exact position on each level was varied dally as was the level on which they were exposed. The exposure period commenced once the restraining tubes were inserted into the chambers and atmosphere generation had started. After six hours atmosphere generation was stopped and the animals were removed starting from the lowest group number. Temperature and relative humidity within each chamber during exposure were measured at approximately 30 minute intervals using a Vaisala HMI 31 portable digital temperature and humidity monitor (supplied by Vaisala UK Ltd. Cambridge, UK). Temperature and relative humidity were generally within the range of 22 ±3°C and 50 ±15% respectively. Some variation was seen in the latter, mainly during the earlier stages of the study and more frequently at the highest concentration but these are not considered to have affected the outcome of the study.Trial generations were carried out during a preliminary study. Atmospheres were generated into a reservoir chamber using a Wright's dust feed mechanism. A glass concentric jet atomiser was used above each exposure to create a venturi, which pulled test atmosphere from the reservoir chamber into the exposure chamber. Clean, dry air (dried and filtered using equipment supplied by Atlas-Copco, Sweden) was supplied to the exposure chamber via the atomiser and also directly, as diluting air. Airflow rates were measured using variable area flowmeters (KDG Flowmeters, Burgess Hill, Sussex, UK}. The airflow rates supplied to the atomisers were nominally: Group 2: 4.3 L/min (range 2.8-5.0 L/min), Group 3: 3.0 L/min (range 2.6-4.3 L/min), Group 4: 5.0 L/min (range 4.0-6.0 L/mln), Group 5: 16.0 L/mln (range 14.0-17.0 L/min}, Dilution air was supplied direct to the exposure chambers at the following flow rates (corrected to normal temperature and pressure): Group 1: 30 L/mln (range 29-30 L/mln), Group 2: 25 L/min (range 23-29 L/mln), Group 3: 25 L/mln (range 21-26 L/mln) Days 3 to 42: Group 4: 15 L/mln (range 15-15 L/min). Days 45 to 95: Group 4: 20 L/mln (range 19-25 L/mln). Days 3 to 42: Group 5: 0 L/mln. Days 45 to 95: Group 5: 8 L/mln (range 6-8 L/mln). At day 45 the volumes of diluting air supplied to the chambers of group 4 and 5 were altered. This was carried out in order to Increase the relative humidity of the air supplied to these chambers. This demonstrated that there were no significant differences in concentration between the top and bottom, and the front and back of the chamber.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Atmospheres were sampled close to the animals breathing zone for determination of captan. The test atmosphere was drawn at a flow rate of 2 L/min over a measured time period, through a 25 mm diameter Vinyl Metrlcel (VN-I) filter housed in a Delrin open-faced filter holder (filters and holders supplied by Gelman Sciences Ltd., Northampton, UK).
The filter was weighed before and after sampling and the concentration was calculated.
All filters and the stages of the Cascade Impactor were store in sealed bottles after weighing prior to subsequent analysis of captan concentration. Test atmospheres were sampled at least 3 times during each exposure period. The amount of material collectes on the filters was insufficient to permit accurate weighing for the 0.1 and 0.5 µg/l captan groups. Therefore only the 5 and 15 µg/L captan concentrations were monitored gravimetrlcally during exposure using pre- and post sampling filter weights. For target concentrations of 0.1 and 0.5 µg/L capatn, a SIMSLIN (Safety in Mines Scattered Light Instrument), connected to a pen recorder was used as an aerosol monitor. This gives a continuous analogue recording which Is related to particulate concentration, thus permitt ng control of the concentration of the atmosphere during exposure. The SIMSLIN was alternated between the 0.1 and 0.5 µg/L captan exposure chambers throughout the exposure period. The 15 µg/L captan group was also monitored using SIMSLIN, starting in week 5. For the reasons given above concerning accuracy of gravimetric analysis of the atmospheres, only the analysed concentrations of captan are reported. The aerodynamJc particle size of the test atmospheres were measured each day during the first week and once a week thereafter by means of a Marple Cascade Impactor {supplied by Shaeffer Instruments Ltd, Wantage, Oxon, UK) which aerodynainically separates airborne particles into pre-determined size ranges The mean amount of analysed captan, in each size range, was then used to calculate the aerodynamic particle size distribution of the aerosol. Using a nicrocomputer the data was transformed using a log/probit transform and a linear regression derived from the cumulative data. Using this regression line, the mass median aerodynamic diameter {D50) and geometric standard deviation (GSD) were calculated.

Duration of treatment / exposure:

13-week inhalation

Frequency of treatment:

six hours per day, 5 days per week

Dose / conc.:

0 mg/L air (nominal)

Remarks:

Doses / Concentrations:0.1 μg/L captan (10/sex/dose)Basis:nominal conc.

Dose / conc.:

0.001 mg/L air (nominal)

Remarks:

Doses / Concentrations:0.5 μg/L captan (10/sex/dose)Basis:nominal conc.

Dose / conc.:

0.005 mg/L air (nominal)

Remarks:

Doses / Concentrations:5.0 μg/L captan (10/sex/dose)Basis:nominal conc.

Dose / conc.:

0.015 mg/L air (nominal)

Remarks:

Doses / Concentrations:15 μg/L captan (20/sex/dose)Basis:nominal conc.

No. of animals per sex per dose:

1. 0.1 μg/L captan (10/sex/dose)
2. 0.5 μg/L captan (10/sex/dose)
3. 5.0 μg/L captan (10/sex/dose)
4. 15 μg/L captan (20/sex/dose)5. control group of 20 males and 20 females was exposed to air only

Control animals:

yes, concurrent vehicle

Details on study design:

In a 13-week inhalation (nose only) study with captan (purity 88.7%, batch number 11240-37-1), ALpk:APfSD (Wistar derived) rats were exposed to nominal concentrations of 0.1, 0.5 and 5.0 μg/L captan (10/sex/dose) and 15 μg/L captan (20/sex) for six hours per day, 5 days per week. Test atmospheres were generated by the suspension of captan particulate in air using a Wright dust feed generator. A concurrent control group of 20 males and 20 females was exposed to air only.

Observations and examinations performed and frequency:

Parameters evaluated were mortality and clinical signs (daily and frequently during exposure body weight and food consumption (weekly), ophthalmoscopy (pretest, week 13 (0 and 15 μg/L) and week 18 (‘recovery’ group), haematology and clinical chemistry (study termination), urinalysis (males in week 13 and females in week 14), gross pathology, organ weights (lungs (with trachea attached but larynx removed), heart, liver, kidneys, brain, adrenal glands and testes) and histopathology. Kidney sections from control and high dose animals were taken for immunocytochemical detection of α-2u-globulin.

Sacrifice and pathology:

At the end of the exposure period 10 males and 10 females from each group were sacrificed from the main study group. The remaining animals (10/sex/dose - control and 15 μg/L) were sacrificed after a 4-week ‘recovery’ period and are referred to as the satellite group.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Four males exposed to 12.98 μg/L captan were found dead over weeks 5 to 13 and another male from the same dose group was killed in extremis in week 11.

Mortality:

mortality observed, treatment-related

Description (incidence):

Four males exposed to 12.98 μg/L captan were found dead over weeks 5 to 13 and another male from the same dose group was killed in extremis in week 11.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A statistically significant reduction in the body weight of males from all test groups compared to the control was noted during week 1. This divergence continued for the duration of the study for all test groups except 0.60 mg/L.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Food intake in 5.06 and 12.98 μg/L males from the main group was reduced by approximately 10% versus controls, although these effects were not consistent and showed no dose relationship.

Food efficiency:

no effects observed

Description (incidence and severity):

Food efficiency was not affected by treatment.

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Blood: There were several statistically significant differences between control and test groups however, these were small and were not dose-related and were therefore considered not to be compound-related.

Urinalysis findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Gross findings in the lungs of animals dead or sacrificed prior to study termination (red discolouration and partial deflation) were considered to be agonal and not treatment-related.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Microscopic changes related to inhalation of captan were seen in the lung, larynx, nasal passages and trachea.

Details on results:

General observations: Four males exposed to 12.98 μg/L captan were found dead over weeks 5 to 13 and another male from the same dose group was killed in extremis in week 11. One 0.13 μg/L female and one 5.06 μg/L female were killed in extremis in week 6 and week 10, respectively, but were considered to be not treatment-related. Any observed clinical signs were associated with restraint and occurred equally in test animals and controls. Respiratory noise was present towards the end of the study, primarily in those animals in the higher dose groups. Mucus nasal secretion was noted in a few females and may have been related to treatment. Body weight gain in females was similar in all dose groups throughout the course of the study. A statistically significant reduction in the body weight of males from all test groups compared to the control was noted during week 1. This divergence continued for the duration of the study for all test groups except 0.60 mg/L, which returned to control levels from week 2 onward. By week 13 final body weights were statistically decreased by 8, 7 and 8% compared to the control in the 0.13, 5.06 and 12.98 μg/L dose groups, respectively. These were not considered to be a toxicologically significant effect. The body weights of males in the main study are summarised in Figure 5.3.3.1-1 (look at attached background material).
In the satellite study, body weight gain by 12.98 μg/L males was significantly lower than controls from week 1 through to the end of the recovery period at week 17. Final body weight was significantly lower than the control (Figure 5.3.3.1-1), (look at attached background material).
Food intake in 5.06 and 12.98 μg/L males from the main group was reduced by approximately 10% versus controls, although these effects were not consistent and showed no dose relationship. Food efficiency was not affected by treatment.
Ophthalmoscopy haematology and clinical chemistry: No treatment-related effects were observed.
Gross pathology, organ weights and histopathology: There were no macroscopic changesrelated to treatment with captan. Gross findings in the lungs of animals dead or sacrificed prior to study termination (red discolouration and partial deflation) were considered to be agonal and not treatment-related.
Microscopic changes related to inhalation of captan were seen in the lung, larynx, nasal passages and trachea. Treatment related (and agonal) effects for intercurrent and main group animals are summarised in Table 5.3.3.1-2 (look at attached background material) and Table 5.3.3.1-3 (look at attached background material).
Following a 4-week recovery period the lung and nasal passage effects had resolved, butthe larengyl effects (Table 5.3.3.1-4) (look at attached background material) were still present in the high dose group.There was no evidence of any treatment-related increase in α-2u-globulin in the kidney in either males or females from the 12.98 μg/L dose group. There were no treatment-related effects on absolute or relative organ weights. The factor contributing to death in intercurrent males exposed to 12.98 μg/L captan was considered to be necrosis of the bronchial/bronchiolar epithelium. This effect was also seen in 5.06 and 12.98 μg/L captan animals that survived to terminal sacrifice. Other treatmentrelated effects were consistent with repeated exposure to an irritant particulate and areconsidered to have no toxicological significance in the context of captan exposure to humans.

Key result

Dose descriptor:

NOEC

Effect level:

0.6 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: The NOEC for toxicological effects was 0.60 μg/L captan in both male and female rats, based on effects in the lung at doses of 5.06 μg/L and above.

Critical effects observed:

not specified

Conclusions:

The NOEC for toxicological effects was 0.60 μg/L captan in both male and female rats, based on effects in the lung at doses of 5.06 μg/L and above. It was not possible to establish an unequivocal NOEC.

Executive summary:

Inhalation of captan may form a route of human exposure. The purpose of this study was to assess the sub-chronic inhalation toxicity of captan, following exposure to rats for 13 weeks (5 exposures/week) to determine effect and no-effect levels. Satellite groups were attached to the control and highest exposure groups and were retained after the last exposure for a 4-week observation period.

The rat was chosen since there is considerable general and toxicologlcal data available to assist in the interpretation of results. The Alpk:APfSD strain was used in the study since relevant background data were available. Groups of 10 male and 10 female AlpK:APfSD rats were exposed nose-only to target concentrations of 0.1, 0.5 or 5.0 µg/l captan, and 20 male and 20 female rats were exposed to 15.0 µg/l captan, for 6 hours per day, 5 days per week for 13 weeks. A concurrent control group of 20 male and 20 female rats was similarly treated but was exposed to air only. Ten males and 10 females from each group were killed in week 14 following their last exposure, and the remaining animals were killed in week 18 following a 4-week 'recovery' phase.

The mean atmospheric concentrations of captan throughout the study, analysed by gas chromatography were 0.13, 0.60, 5.06 and 12.98 µg/l. The test atmospheres had study mean mass median aerodynamic diameters of 0.95, 1.22, 1.57 and l.60 µm respectively for the 0.13, 0.60, 5.06 and 12.98 µg/l captan exposure levels and respective geometric standard deviations of 1.82, 1.80, 1.84 and 2.00.

No treatment-related changes were seen in ophthalmoscopy, clinical chemistry or haematological parameters in any exposed group. No evidence of kidney toxicity was seen in this study. Treatment-related effects were confined to the respiratory tract, were consistent with exposure to an irritant particulate and affects in the lung were considered responsible for five male mortalities during the study in the group exposed to 12.98 µg/l captan. Lungs from animals allowed to recover for 4weeks were completely normal. 0.60 µg/l captan is considered to be a no-effect level for the lung. The larynx was the only other organ to be affected. Effects considered to be of toxicological significance were seen at 12.98 and 5.06 µg/l. Effects considered to be an adaptive response to irritants were seen at the lower concentration. The toxicological no-effect level for inhalation (NOEL) for captan was considered to be 0.60 µg/l.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEC

300 mg/m³

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: inhalation - local effects

Link to relevant study records

Reference

Endpoint:

sub-chronic toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

17 October 1988 to 19 January 1989

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EU Method B.29 (Sub-Chronic Inhalation Toxicity:90-Day Study)

Deviations:

yes

Remarks:

Temperature and humidity levels were occasionally outside nominal range. One male and one female (both 12.98 μg/L) were returned to the wrong holding cage, resulting in pregnancy. The pregnant animal was subsequently terminated.

Qualifier:

according to guideline

Guideline:

EPA OPP 82-4 (90-Day Inhalation Toxicity)

Deviations:

yes

Remarks:

Temperature and humidity levels were occasionally outside nominal range. One male and one female (both 12.98 μg/L) were returned to the wrong holding cage, resulting in pregnancy. The pregnant animal was subsequently terminated.

GLP compliance:

yes

Limit test:

yes

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

- groups of 40 male and 40 female specific pathogen free, A1pk:APfSD (Wistar derived), albino rats
- Source: Barriered Animal Breeding Unit (BABU) Alderley Park. Cheshire. UK
- age: five to six weeks
- free access to mains drinking water and food, except during exposure periods when all food and water was removed.
- room temperature: 20-24°C
- relative humidity: 40-60%

Route of administration:

inhalation: dust

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

Animals were exposed nose-only in restraining tubes supplied by Battelle, Geneva. Switzerland, which were Inserted into an ICl designed PERSPEX exposure chamber having an internal volume of approximately 46 litres. Animals were placed in the exposure chambers in replicate order with male and females on separate levels. Their exact position on each level was varied dally as was the level on which they were exposed. The exposure period commenced once the restraining tubes were inserted into the chambers and atmosphere generation had started. After six hours atmosphere generation was stopped and the animals were removed starting from the lowest group number. Temperature and relative humidity within each chamber during exposure were measured at approximately 30 minute intervals using a Vaisala HMI 31 portable digital temperature and humidity monitor (supplied by Vaisala UK Ltd. Cambridge, UK). Temperature and relative humidity were generally within the range of 22 ±3°C and 50 ±15% respectively. Some variation was seen in the latter, mainly during the earlier stages of the study and more frequently at the highest concentration but these are not considered to have affected the outcome of the study.Trial generations were carried out during a preliminary study. Atmospheres were generated into a reservoir chamber using a Wright's dust feed mechanism. A glass concentric jet atomiser was used above each exposure to create a venturi, which pulled test atmosphere from the reservoir chamber into the exposure chamber. Clean, dry air (dried and filtered using equipment supplied by Atlas-Copco, Sweden) was supplied to the exposure chamber via the atomiser and also directly, as diluting air. Airflow rates were measured using variable area flowmeters (KDG Flowmeters, Burgess Hill, Sussex, UK}. The airflow rates supplied to the atomisers were nominally: Group 2: 4.3 L/min (range 2.8-5.0 L/min), Group 3: 3.0 L/min (range 2.6-4.3 L/min), Group 4: 5.0 L/min (range 4.0-6.0 L/mln), Group 5: 16.0 L/mln (range 14.0-17.0 L/min}, Dilution air was supplied direct to the exposure chambers at the following flow rates (corrected to normal temperature and pressure): Group 1: 30 L/mln (range 29-30 L/mln), Group 2: 25 L/min (range 23-29 L/mln), Group 3: 25 L/mln (range 21-26 L/mln) Days 3 to 42: Group 4: 15 L/mln (range 15-15 L/min). Days 45 to 95: Group 4: 20 L/mln (range 19-25 L/mln). Days 3 to 42: Group 5: 0 L/mln. Days 45 to 95: Group 5: 8 L/mln (range 6-8 L/mln). At day 45 the volumes of diluting air supplied to the chambers of group 4 and 5 were altered. This was carried out in order to Increase the relative humidity of the air supplied to these chambers. This demonstrated that there were no significant differences in concentration between the top and bottom, and the front and back of the chamber.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Atmospheres were sampled close to the animals breathing zone for determination of captan. The test atmosphere was drawn at a flow rate of 2 L/min over a measured time period, through a 25 mm diameter Vinyl Metrlcel (VN-I) filter housed in a Delrin open-faced filter holder (filters and holders supplied by Gelman Sciences Ltd., Northampton, UK).
The filter was weighed before and after sampling and the concentration was calculated.
All filters and the stages of the Cascade Impactor were store in sealed bottles after weighing prior to subsequent analysis of captan concentration. Test atmospheres were sampled at least 3 times during each exposure period. The amount of material collectes on the filters was insufficient to permit accurate weighing for the 0.1 and 0.5 µg/l captan groups. Therefore only the 5 and 15 µg/L captan concentrations were monitored gravimetrlcally during exposure using pre- and post sampling filter weights. For target concentrations of 0.1 and 0.5 µg/L capatn, a SIMSLIN (Safety in Mines Scattered Light Instrument), connected to a pen recorder was used as an aerosol monitor. This gives a continuous analogue recording which Is related to particulate concentration, thus permitt ng control of the concentration of the atmosphere during exposure. The SIMSLIN was alternated between the 0.1 and 0.5 µg/L captan exposure chambers throughout the exposure period. The 15 µg/L captan group was also monitored using SIMSLIN, starting in week 5. For the reasons given above concerning accuracy of gravimetric analysis of the atmospheres, only the analysed concentrations of captan are reported. The aerodynamJc particle size of the test atmospheres were measured each day during the first week and once a week thereafter by means of a Marple Cascade Impactor {supplied by Shaeffer Instruments Ltd, Wantage, Oxon, UK) which aerodynainically separates airborne particles into pre-determined size ranges The mean amount of analysed captan, in each size range, was then used to calculate the aerodynamic particle size distribution of the aerosol. Using a nicrocomputer the data was transformed using a log/probit transform and a linear regression derived from the cumulative data. Using this regression line, the mass median aerodynamic diameter {D50) and geometric standard deviation (GSD) were calculated.

Duration of treatment / exposure:

13-week inhalation

Frequency of treatment:

six hours per day, 5 days per week

Dose / conc.:

0 mg/L air (nominal)

Remarks:

Doses / Concentrations:0.1 μg/L captan (10/sex/dose)Basis:nominal conc.

Dose / conc.:

0.001 mg/L air (nominal)

Remarks:

Doses / Concentrations:0.5 μg/L captan (10/sex/dose)Basis:nominal conc.

Dose / conc.:

0.005 mg/L air (nominal)

Remarks:

Doses / Concentrations:5.0 μg/L captan (10/sex/dose)Basis:nominal conc.

Dose / conc.:

0.015 mg/L air (nominal)

Remarks:

Doses / Concentrations:15 μg/L captan (20/sex/dose)Basis:nominal conc.

No. of animals per sex per dose:

1. 0.1 μg/L captan (10/sex/dose)
2. 0.5 μg/L captan (10/sex/dose)
3. 5.0 μg/L captan (10/sex/dose)
4. 15 μg/L captan (20/sex/dose)5. control group of 20 males and 20 females was exposed to air only

Control animals:

yes, concurrent vehicle

Details on study design:

In a 13-week inhalation (nose only) study with captan (purity 88.7%, batch number 11240-37-1), ALpk:APfSD (Wistar derived) rats were exposed to nominal concentrations of 0.1, 0.5 and 5.0 μg/L captan (10/sex/dose) and 15 μg/L captan (20/sex) for six hours per day, 5 days per week. Test atmospheres were generated by the suspension of captan particulate in air using a Wright dust feed generator. A concurrent control group of 20 males and 20 females was exposed to air only.

Observations and examinations performed and frequency:

Parameters evaluated were mortality and clinical signs (daily and frequently during exposure body weight and food consumption (weekly), ophthalmoscopy (pretest, week 13 (0 and 15 μg/L) and week 18 (‘recovery’ group), haematology and clinical chemistry (study termination), urinalysis (males in week 13 and females in week 14), gross pathology, organ weights (lungs (with trachea attached but larynx removed), heart, liver, kidneys, brain, adrenal glands and testes) and histopathology. Kidney sections from control and high dose animals were taken for immunocytochemical detection of α-2u-globulin.

Sacrifice and pathology:

At the end of the exposure period 10 males and 10 females from each group were sacrificed from the main study group. The remaining animals (10/sex/dose - control and 15 μg/L) were sacrificed after a 4-week ‘recovery’ period and are referred to as the satellite group.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Four males exposed to 12.98 μg/L captan were found dead over weeks 5 to 13 and another male from the same dose group was killed in extremis in week 11.

Mortality:

mortality observed, treatment-related

Description (incidence):

Four males exposed to 12.98 μg/L captan were found dead over weeks 5 to 13 and another male from the same dose group was killed in extremis in week 11.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

A statistically significant reduction in the body weight of males from all test groups compared to the control was noted during week 1. This divergence continued for the duration of the study for all test groups except 0.60 mg/L.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Food intake in 5.06 and 12.98 μg/L males from the main group was reduced by approximately 10% versus controls, although these effects were not consistent and showed no dose relationship.

Food efficiency:

no effects observed

Description (incidence and severity):

Food efficiency was not affected by treatment.

Water consumption and compound intake (if drinking water study):

not specified

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

effects observed, non-treatment-related

Description (incidence and severity):

Blood: There were several statistically significant differences between control and test groups however, these were small and were not dose-related and were therefore considered not to be compound-related.

Urinalysis findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Gross findings in the lungs of animals dead or sacrificed prior to study termination (red discolouration and partial deflation) were considered to be agonal and not treatment-related.

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Microscopic changes related to inhalation of captan were seen in the lung, larynx, nasal passages and trachea.

Details on results:

General observations: Four males exposed to 12.98 μg/L captan were found dead over weeks 5 to 13 and another male from the same dose group was killed in extremis in week 11. One 0.13 μg/L female and one 5.06 μg/L female were killed in extremis in week 6 and week 10, respectively, but were considered to be not treatment-related. Any observed clinical signs were associated with restraint and occurred equally in test animals and controls. Respiratory noise was present towards the end of the study, primarily in those animals in the higher dose groups. Mucus nasal secretion was noted in a few females and may have been related to treatment. Body weight gain in females was similar in all dose groups throughout the course of the study. A statistically significant reduction in the body weight of males from all test groups compared to the control was noted during week 1. This divergence continued for the duration of the study for all test groups except 0.60 mg/L, which returned to control levels from week 2 onward. By week 13 final body weights were statistically decreased by 8, 7 and 8% compared to the control in the 0.13, 5.06 and 12.98 μg/L dose groups, respectively. These were not considered to be a toxicologically significant effect. The body weights of males in the main study are summarised in Figure 5.3.3.1-1 (look at attached background material).
In the satellite study, body weight gain by 12.98 μg/L males was significantly lower than controls from week 1 through to the end of the recovery period at week 17. Final body weight was significantly lower than the control (Figure 5.3.3.1-1), (look at attached background material).
Food intake in 5.06 and 12.98 μg/L males from the main group was reduced by approximately 10% versus controls, although these effects were not consistent and showed no dose relationship. Food efficiency was not affected by treatment.
Ophthalmoscopy haematology and clinical chemistry: No treatment-related effects were observed.
Gross pathology, organ weights and histopathology: There were no macroscopic changesrelated to treatment with captan. Gross findings in the lungs of animals dead or sacrificed prior to study termination (red discolouration and partial deflation) were considered to be agonal and not treatment-related.
Microscopic changes related to inhalation of captan were seen in the lung, larynx, nasal passages and trachea. Treatment related (and agonal) effects for intercurrent and main group animals are summarised in Table 5.3.3.1-2 (look at attached background material) and Table 5.3.3.1-3 (look at attached background material).
Following a 4-week recovery period the lung and nasal passage effects had resolved, butthe larengyl effects (Table 5.3.3.1-4) (look at attached background material) were still present in the high dose group.There was no evidence of any treatment-related increase in α-2u-globulin in the kidney in either males or females from the 12.98 μg/L dose group. There were no treatment-related effects on absolute or relative organ weights. The factor contributing to death in intercurrent males exposed to 12.98 μg/L captan was considered to be necrosis of the bronchial/bronchiolar epithelium. This effect was also seen in 5.06 and 12.98 μg/L captan animals that survived to terminal sacrifice. Other treatmentrelated effects were consistent with repeated exposure to an irritant particulate and areconsidered to have no toxicological significance in the context of captan exposure to humans.

Key result

Dose descriptor:

NOEC

Effect level:

0.6 mg/m³ air (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: The NOEC for toxicological effects was 0.60 μg/L captan in both male and female rats, based on effects in the lung at doses of 5.06 μg/L and above.

Critical effects observed:

not specified

Conclusions:

The NOEC for toxicological effects was 0.60 μg/L captan in both male and female rats, based on effects in the lung at doses of 5.06 μg/L and above. It was not possible to establish an unequivocal NOEC.

Executive summary:

Inhalation of captan may form a route of human exposure. The purpose of this study was to assess the sub-chronic inhalation toxicity of captan, following exposure to rats for 13 weeks (5 exposures/week) to determine effect and no-effect levels. Satellite groups were attached to the control and highest exposure groups and were retained after the last exposure for a 4-week observation period.

The rat was chosen since there is considerable general and toxicologlcal data available to assist in the interpretation of results. The Alpk:APfSD strain was used in the study since relevant background data were available. Groups of 10 male and 10 female AlpK:APfSD rats were exposed nose-only to target concentrations of 0.1, 0.5 or 5.0 µg/l captan, and 20 male and 20 female rats were exposed to 15.0 µg/l captan, for 6 hours per day, 5 days per week for 13 weeks. A concurrent control group of 20 male and 20 female rats was similarly treated but was exposed to air only. Ten males and 10 females from each group were killed in week 14 following their last exposure, and the remaining animals were killed in week 18 following a 4-week 'recovery' phase.

The mean atmospheric concentrations of captan throughout the study, analysed by gas chromatography were 0.13, 0.60, 5.06 and 12.98 µg/l. The test atmospheres had study mean mass median aerodynamic diameters of 0.95, 1.22, 1.57 and l.60 µm respectively for the 0.13, 0.60, 5.06 and 12.98 µg/l captan exposure levels and respective geometric standard deviations of 1.82, 1.80, 1.84 and 2.00.

No treatment-related changes were seen in ophthalmoscopy, clinical chemistry or haematological parameters in any exposed group. No evidence of kidney toxicity was seen in this study. Treatment-related effects were confined to the respiratory tract, were consistent with exposure to an irritant particulate and affects in the lung were considered responsible for five male mortalities during the study in the group exposed to 12.98 µg/l captan. Lungs from animals allowed to recover for 4weeks were completely normal. 0.60 µg/l captan is considered to be a no-effect level for the lung. The larynx was the only other organ to be affected. Effects considered to be of toxicological significance were seen at 12.98 and 5.06 µg/l. Effects considered to be an adaptive response to irritants were seen at the lower concentration. The toxicological no-effect level for inhalation (NOEL) for captan was considered to be 0.60 µg/l.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEC

0.6 mg/m³

Study duration:

subchronic

Species:

rat

Repeated dose toxicity: dermal - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 January to 20 February 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPP 82-2 (Repeated Dose Dermal Toxicity -21/28 Days)

Deviations:

no

GLP compliance:

yes

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Details on species / strain selection:

New Zealand White rabbits; Hazleton Dutchland, Denver, Pennsylvania; approximately 3 1/2 month old at initiation.

Sex:

male/female

Type of coverage:

occlusive

Vehicle:

water

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

21 days

Frequency of treatment:

five days per week

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Dose / conc.:

110 mg/kg bw/day (nominal)

Dose / conc.:

12.5 mg/kg bw/day (nominal)

No. of animals per sex per dose:

5/sex/dose group

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

Parameters evaluated were clinical signs (daily), general appearance, behaviour and pharmacotoxic signs and dermal irritation (pretest and days 2, 4, 8, 11, 15, 18 and 21), body weight (pretest and twice weekly), food intake (weekly), haematology and clinical chemistry (day 21)

Sacrifice and pathology:

Organ weights (adrenal, brain, kidney, liver, ovary, testis), gross pathology and histopathology (adrenal, brain, kidney, liver, lung, ovary, testis, skin, spleen and gross lesions).

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

There were no signs of dermal irritation at the application sites in the control animals. Animals in the 12.5 mg/kg bw and 110 mg/kg bw were also normal apart from very slight desquamation in one 12.5 mg/kg bw female on day 21 and slight erythema observed in two 110 mg/kg bw females on day 21. Slight erythema, oedema and desquamation were observed starting at day 4 in some animals in the 1,000 mg/kg bw group.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One 110 mg/kg bw female was found dead on day 9 of the test, but the death was considered to be unrelated to exposure of captan.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight gain and food consumption in 12.5 and 110 mg/kg bw animals were comparable to the control animals and no signs of overt toxicity were noted. The body weight of 1,000 mg/kg females was significantly lower than the control on day 22.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Significant differences in food consumption were noted between the 1,000 mg/kg bw dose group and the control in weeks 2 and/or 3.

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

Treatment-related changes noted at autopsy were observed at the application sites and were limited to mild desquamation in one 12.5 mg/kg bw female and in one male and three females from the 1,000 mg/kg bw dose group.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Whereas microscopic changes to the site of application occurred in all dose groups there was no apparent dose-relationship.

Key result

Dose descriptor:

NOEL

Effect level:

110 mg/kg bw (total dose)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Dose descriptor:

NOEL

Effect level:

12.5 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

dermal irritation

Critical effects observed:

not specified

General observations: Body weight gain and food consumption in 12.5 and 110 mg/kg bw animals were comparable to the control animals and no signs of overt toxicity were noted. One 110 mg/kg bw female was found dead on day 9 of the test, but the death was considered to be unrelated to exposure of captan. The body weight of 1000 mg/kg females was significantly lower than the control on day 22. Significant differences in food consumption were noted between the 1000 mg/kg bw dose group and the control in weeks 2 and/or 3.

Local findings: There were no signs of dermal irritation at the application sites in the control animals. Animals in the 12.5 mg/kg bw and 110 mg/kg bw were also normal apart from very slight desquamation in one 12.5 mg/kg bw female on day 21 and slight erythema observed in two 110 mg/kg bw females on day 21. Slight erythema, oedema and desquamation were observed starting at day 4 in some animals in the 1000 mg/kg bw group. Haematology and clinical chemistry: There were no treatment-related effects on haematological or clinical chemistry parameters.

Gross pathology, organ weights and histopatholgy: Treatment-related changes noted at autopsy were observed at the application sites and were limited to mild desquamation in one 12.5 mg/kg bw female and in one male and three females from the 1000 mg/kg bw dose group. Whereas microscopic changes to the site of application occurred in all dose groups there was no apparent dose-relationship.

7.5.3-1 Subacute dermal study on rabbits: summary of female body weights (mean ± sd)

Day	Body weight (g)
	0 mg/kg bw	12.5 mg/kg bw	110 mg/kg bw	1000 mg/kg bw
0	2422 ± 113.1	2441 ± 135.8	2414 ± 175.4	2407 ± 175.3
3	2430 ± 137.9	2450 ± 140.4	2429 ± 199.7	2302 ± 158.2
7	2433 ± 281.2	2534 ± 140.1	2522 ± 250.0	2290 ± 215.3
10	2588 ± 126.8	2585 ± 143.1	2664 ± 264.0	2336 ± 167.5
14	2680 ± 156.4	2684 ± 170.7	2742 ± 304.2	2387 ± 220.1
17	2745 ± 156.6	2736 ± 179.4	2830 ± 324.7	2387 ± 201.9
22	2793 ± 125.6	2819 ± 171.4	2893 ± 333.8	2429 ± 163.0*

* Significantly different from the control (p < 0.05).

7.5.3-2 Subacute dermal study on rabbits: summary of food consumption (mean ± sd)

week	Food consumption (g/animal/day)
	0 mg/kg bw	12.5 mg/kg bw	110 mg/kg bw	1000 mg/kg bw
males
1	127.9 ± 59.57	163.8 ± 85.35	144.4 ± 20.99	81.1 ± 13.93
2	170.7 ± 35.82	159.2 ± 33.12	161.3 ± 11.05	110.3 ± 26.10^*
3	132.3 ± 23.58	129.9 ± 41.78	134.9 ± 11.34	110.9 ± 12.18
females
1	124.0 ± 52.41	150.3 ± 17.75	128.7 ± 41.98	76.5 ± 35.90
2	159.7 ± 27.28	161.3 ± 18.86	160.0 ± 23.14	107.4 ± 15.84^**
3	137.4 ± 15.75	137.1 ± 16.33	135.0 ± 14.96	92.3 ± 22.23^**

* Significantly different from the control (p < 0.05);

** significantly different from the control (p < 0.01).

7.5.3-3 Subacute dermal study on rabbits: summary of dermal findings in 1000 mg/kg bw dose group animals

Dermal Sign		Days
		2		4		8		11		15		18		21
		m	f	m	f	m	f	m	f	m	f	m	f	m	f
Erythema	None	5	5	5	3	5	4	5	5	5	4	2	2	2	2
	Very slight	0	0	0	2	0	1	0	0	0	1	3	3	3	3
	Well defined	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Moderate to severe	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Severe	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Oedema	None	5	5	5	5	5	5	5	5	5	5	2	3	2	3
	Very slight	0	0	0	0	0	0	0	0	0	0	3	2	3	2
	Slight	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Moderate	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Severe	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Atonia	Normal	5	5	5	5	5	5	5	5	5	5	5	4	5	5
	Slight	0	0	0	0	0	0	0	0	0	0	0	1	0	0
	Moderate	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Marked	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Desquamation	None	5	5	5	5	5	5	5	5	5	3	1	1	1	1
	Slight	0	0	0	0	0	0	0	0	0	2	4	4	4	3
	Moderate	0	0	0	0	0	0	0	0	0	0	0	0	0	1
	Marked	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Number of animals		5	5	5	5	5	5	5	5	5	5	5	5	5	5

m=males, f=females

Conclusions:

The NOEL for systemic effects was 110 mg/kg bw in both males and females, based on reduced food consumption (males and females) and body weight (females). The NOEL for local effects was less than 12.5 mg/kg bw in both males and females, based on dermal irritation changes to the skin observed at the macroscopic and microscopic level in the lowest dose group tested.

Executive summary:

Dermal effects on New Zealand White rabbits were studied according to EPA OPP 83-1. Five animals per sex an dose were chosen for examination. 12.5, 110 and 1000 mg/kg bw were used. 

Animals in the 12.5 mg/kg groups were similar to the control animals in body weight gain and food consumption and there were no signs of test article related overt toxicity noted in these groups during the course of the study. At 1000 mg/kg, however, animals had decreased body weight gains and decreased food consumption (g/animal/day and g/kg/day) in both sexes achieved statistical significance as compared to control values at one or more intervals during the study. The 1000 mg/kg animals also exhibited a higher degree of dermal irritation at the application site than animals in the other groups. Overall, the irritation produced by the test article was minimal.

Other than the body weight and food consumption decrement in the 1000 mg/kg animals, there was no evidence of the test article related systemic toxicity in any animal. Results of clinical pathology determinations in treated animals were similar control values, with minor differences attributed to animal variation. Organ weight differences that occurred were due to normal animal variation and/or body weight differences in the high dose females.

One female from the 110 mg/kg group was found dead on the study day 9. The salient lesion in this animal was severe hemorrhagic ileitis, which was considered to be spontaneous and unrelated to administration of the test article.

There were microscopic test article related dermal findings that occurred in animals from all treated groups with no apparent dose response. In males, the changes consisted of acanthosis and hyperkeratosis. In females, the findings included acanthosis, hyperkeratosis and subacute dermatitis. All other microscopic findings were judged to be spontaneous and/or incidental in nature.

In summary the NOEL for systemic effects was 110 mg/kg bw in both males and females, based on reduced food consumption (males and females) and body weight (females). The NOEL for local effects was less than 12.5 mg/kg bw in both males and females, based on dermal irritation changes to the skin observed at the macroscopic and microscopic level in the lowest dose group tested.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

110 mg/kg bw/day

Study duration:

subacute

Species:

rabbit

Repeated dose toxicity: dermal - local effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: dermal

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 January to 20 February 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EPA OPP 82-2 (Repeated Dose Dermal Toxicity -21/28 Days)

Deviations:

no

GLP compliance:

yes

Limit test:

yes

Species:

rabbit

Strain:

New Zealand White

Details on species / strain selection:

New Zealand White rabbits; Hazleton Dutchland, Denver, Pennsylvania; approximately 3 1/2 month old at initiation.

Sex:

male/female

Type of coverage:

occlusive

Vehicle:

water

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

21 days

Frequency of treatment:

five days per week

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Dose / conc.:

110 mg/kg bw/day (nominal)

Dose / conc.:

12.5 mg/kg bw/day (nominal)

No. of animals per sex per dose:

5/sex/dose group

Control animals:

yes, concurrent vehicle

Observations and examinations performed and frequency:

Parameters evaluated were clinical signs (daily), general appearance, behaviour and pharmacotoxic signs and dermal irritation (pretest and days 2, 4, 8, 11, 15, 18 and 21), body weight (pretest and twice weekly), food intake (weekly), haematology and clinical chemistry (day 21)

Sacrifice and pathology:

Organ weights (adrenal, brain, kidney, liver, ovary, testis), gross pathology and histopathology (adrenal, brain, kidney, liver, lung, ovary, testis, skin, spleen and gross lesions).

Dermal irritation:

effects observed, treatment-related

Description (incidence and severity):

There were no signs of dermal irritation at the application sites in the control animals. Animals in the 12.5 mg/kg bw and 110 mg/kg bw were also normal apart from very slight desquamation in one 12.5 mg/kg bw female on day 21 and slight erythema observed in two 110 mg/kg bw females on day 21. Slight erythema, oedema and desquamation were observed starting at day 4 in some animals in the 1,000 mg/kg bw group.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

One 110 mg/kg bw female was found dead on day 9 of the test, but the death was considered to be unrelated to exposure of captan.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Body weight gain and food consumption in 12.5 and 110 mg/kg bw animals were comparable to the control animals and no signs of overt toxicity were noted. The body weight of 1,000 mg/kg females was significantly lower than the control on day 22.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Significant differences in food consumption were noted between the 1,000 mg/kg bw dose group and the control in weeks 2 and/or 3.

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

Treatment-related changes noted at autopsy were observed at the application sites and were limited to mild desquamation in one 12.5 mg/kg bw female and in one male and three females from the 1,000 mg/kg bw dose group.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

Whereas microscopic changes to the site of application occurred in all dose groups there was no apparent dose-relationship.

Key result

Dose descriptor:

NOEL

Effect level:

110 mg/kg bw (total dose)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Dose descriptor:

NOEL

Effect level:

12.5 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

dermal irritation

Critical effects observed:

not specified

General observations: Body weight gain and food consumption in 12.5 and 110 mg/kg bw animals were comparable to the control animals and no signs of overt toxicity were noted. One 110 mg/kg bw female was found dead on day 9 of the test, but the death was considered to be unrelated to exposure of captan. The body weight of 1000 mg/kg females was significantly lower than the control on day 22. Significant differences in food consumption were noted between the 1000 mg/kg bw dose group and the control in weeks 2 and/or 3.

Local findings: There were no signs of dermal irritation at the application sites in the control animals. Animals in the 12.5 mg/kg bw and 110 mg/kg bw were also normal apart from very slight desquamation in one 12.5 mg/kg bw female on day 21 and slight erythema observed in two 110 mg/kg bw females on day 21. Slight erythema, oedema and desquamation were observed starting at day 4 in some animals in the 1000 mg/kg bw group. Haematology and clinical chemistry: There were no treatment-related effects on haematological or clinical chemistry parameters.

Gross pathology, organ weights and histopatholgy: Treatment-related changes noted at autopsy were observed at the application sites and were limited to mild desquamation in one 12.5 mg/kg bw female and in one male and three females from the 1000 mg/kg bw dose group. Whereas microscopic changes to the site of application occurred in all dose groups there was no apparent dose-relationship.

7.5.3-1 Subacute dermal study on rabbits: summary of female body weights (mean ± sd)

Day	Body weight (g)
	0 mg/kg bw	12.5 mg/kg bw	110 mg/kg bw	1000 mg/kg bw
0	2422 ± 113.1	2441 ± 135.8	2414 ± 175.4	2407 ± 175.3
3	2430 ± 137.9	2450 ± 140.4	2429 ± 199.7	2302 ± 158.2
7	2433 ± 281.2	2534 ± 140.1	2522 ± 250.0	2290 ± 215.3
10	2588 ± 126.8	2585 ± 143.1	2664 ± 264.0	2336 ± 167.5
14	2680 ± 156.4	2684 ± 170.7	2742 ± 304.2	2387 ± 220.1
17	2745 ± 156.6	2736 ± 179.4	2830 ± 324.7	2387 ± 201.9
22	2793 ± 125.6	2819 ± 171.4	2893 ± 333.8	2429 ± 163.0*

* Significantly different from the control (p < 0.05).

7.5.3-2 Subacute dermal study on rabbits: summary of food consumption (mean ± sd)

week	Food consumption (g/animal/day)
	0 mg/kg bw	12.5 mg/kg bw	110 mg/kg bw	1000 mg/kg bw
males
1	127.9 ± 59.57	163.8 ± 85.35	144.4 ± 20.99	81.1 ± 13.93
2	170.7 ± 35.82	159.2 ± 33.12	161.3 ± 11.05	110.3 ± 26.10^*
3	132.3 ± 23.58	129.9 ± 41.78	134.9 ± 11.34	110.9 ± 12.18
females
1	124.0 ± 52.41	150.3 ± 17.75	128.7 ± 41.98	76.5 ± 35.90
2	159.7 ± 27.28	161.3 ± 18.86	160.0 ± 23.14	107.4 ± 15.84^**
3	137.4 ± 15.75	137.1 ± 16.33	135.0 ± 14.96	92.3 ± 22.23^**

* Significantly different from the control (p < 0.05);

** significantly different from the control (p < 0.01).

7.5.3-3 Subacute dermal study on rabbits: summary of dermal findings in 1000 mg/kg bw dose group animals

Dermal Sign		Days
		2		4		8		11		15		18		21
		m	f	m	f	m	f	m	f	m	f	m	f	m	f
Erythema	None	5	5	5	3	5	4	5	5	5	4	2	2	2	2
	Very slight	0	0	0	2	0	1	0	0	0	1	3	3	3	3
	Well defined	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Moderate to severe	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Severe	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Oedema	None	5	5	5	5	5	5	5	5	5	5	2	3	2	3
	Very slight	0	0	0	0	0	0	0	0	0	0	3	2	3	2
	Slight	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Moderate	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Severe	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Atonia	Normal	5	5	5	5	5	5	5	5	5	5	5	4	5	5
	Slight	0	0	0	0	0	0	0	0	0	0	0	1	0	0
	Moderate	0	0	0	0	0	0	0	0	0	0	0	0	0	0
	Marked	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Desquamation	None	5	5	5	5	5	5	5	5	5	3	1	1	1	1
	Slight	0	0	0	0	0	0	0	0	0	2	4	4	4	3
	Moderate	0	0	0	0	0	0	0	0	0	0	0	0	0	1
	Marked	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Number of animals		5	5	5	5	5	5	5	5	5	5	5	5	5	5

m=males, f=females

Conclusions:

The NOEL for systemic effects was 110 mg/kg bw in both males and females, based on reduced food consumption (males and females) and body weight (females). The NOEL for local effects was less than 12.5 mg/kg bw in both males and females, based on dermal irritation changes to the skin observed at the macroscopic and microscopic level in the lowest dose group tested.

Executive summary:

Dermal effects on New Zealand White rabbits were studied according to EPA OPP 83-1. Five animals per sex an dose were chosen for examination. 12.5, 110 and 1000 mg/kg bw were used. 

Animals in the 12.5 mg/kg groups were similar to the control animals in body weight gain and food consumption and there were no signs of test article related overt toxicity noted in these groups during the course of the study. At 1000 mg/kg, however, animals had decreased body weight gains and decreased food consumption (g/animal/day and g/kg/day) in both sexes achieved statistical significance as compared to control values at one or more intervals during the study. The 1000 mg/kg animals also exhibited a higher degree of dermal irritation at the application site than animals in the other groups. Overall, the irritation produced by the test article was minimal.

Other than the body weight and food consumption decrement in the 1000 mg/kg animals, there was no evidence of the test article related systemic toxicity in any animal. Results of clinical pathology determinations in treated animals were similar control values, with minor differences attributed to animal variation. Organ weight differences that occurred were due to normal animal variation and/or body weight differences in the high dose females.

One female from the 110 mg/kg group was found dead on the study day 9. The salient lesion in this animal was severe hemorrhagic ileitis, which was considered to be spontaneous and unrelated to administration of the test article.

There were microscopic test article related dermal findings that occurred in animals from all treated groups with no apparent dose response. In males, the changes consisted of acanthosis and hyperkeratosis. In females, the findings included acanthosis, hyperkeratosis and subacute dermatitis. All other microscopic findings were judged to be spontaneous and/or incidental in nature.

In summary the NOEL for systemic effects was 110 mg/kg bw in both males and females, based on reduced food consumption (males and females) and body weight (females). The NOEL for local effects was less than 12.5 mg/kg bw in both males and females, based on dermal irritation changes to the skin observed at the macroscopic and microscopic level in the lowest dose group tested.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

0.48 mg/cm²

Study duration:

subacute

Species:

rabbit

Additional information

In summary the NOEL for systemic effects was 110 mg/kg bw in both males and females, based on reduced food consumption (males and females) and body weight (females). The NOEL for local effects was less than 12.5 mg/kg bw in both males and females, based on dermal irritation changes to the skin observed at the macroscopic and microscopic level in the lowest dose group tested. Nevertheless care has to be taken on sensitizing properties of captan. In maximisation test (Dreher, D.M. 1991) captan was found to be an extreme sensitizer.

Captan technical was well tolerated by dogs when administered orally in gelatin capsules at dose levels up to 300 mg/kg bw/day for 52 weeks. There was some emesis and soft/mucoid stool at the 300 mg/kg bw bw/day level. However, these signs were regarded as a response to the taste and physical nature of the test substance rather than a toxicological effect. Daily dosage of higher than 300 mg/kg was considered likely to result in significant toxicity and potentially lead to deaths in a one year study. The NOEL for oral administration of captan is set to 300 mg/kg bw/day in both male and female dogs.

For inhalation exposure no treatment-related changes were seen in ophthalmoscopy, clinical chemistry or haematological parameters in any exposed group. Even no evidence of kidney toxicity was found. Treatment-related effects were confined to the respiratory tract and were consistent with exposure to an irritant particulate and affects in the lung were considered responsible for five male mortalities during the study in the group exposed to 12.98 µg/l captan. Lungs from animals allowed to recover for 4 weeks were completely normal.

0.60 µg/l captan is considered to be a no-effect level for the lung. Larynx was the only other organ to be affected. Effects considered to be of toxicological significance were seen at 12.98 and 5.06 µg/l. Effects considered to be an adaptive response to irritants were seen at the lower concentration. The toxicological no-effect level for inhalation (NOEL) for captan was considered to be 0.60 µg/l.

Dermal effects on New Zealand White rabbits were studied to evaluate repeated dose effects on skin. Results of clinical pathology determinations in treated animals were similar control values, with minor differences attributed to animal variation. Organ weight differences that occurred were due to normal animal variation and/or body weight differences in the high dose females. At 1000 mg/kg animals had decreased body weight gains and decreased food consumption

There were microscopic test article related dermal findings that occurred in animals from all treated groups with no apparent dose response. In males, the changes consisted of acanthosis and hyperkeratosis. In females, the findings included acanthosis, hyperkeratosis and subacute dermatitis. All other microscopic findings were judged to be spontaneous and/or incidental in nature.

Justification for classification or non-classification

In respect to repeated dose toxicity studies through all possible exposure paths (oral, dermal, inhalation) no additional classification is necessary. Effects on the respiratory system already found by acute toxicity study (acute toxic by inhalation cat. 3) were confirmed. No severe effects were found neither by oral nor by dermal contact.

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