Clorofene

Endpoint summary

Description of key information

Subchronic repeated dose toxicity, oral, dog: NOAEL = 10 mg/kg bw/day

Subacute repeated dose toxicity, dermal, rabbit: NOAEL = 10 mg/kg bw/day

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

10 mg/kg bw/day

Study duration:

subchronic

Species:

dog

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 1 and 2) and consistent studies, and is thus sufficient to fulfil the standard information requirements set out in Annex VIII-IX, 8.6, of Regulation (EC) No 1907/2006.

System:

urinary

Organ:

kidney

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

10 mg/kg bw/day

Study duration:

subacute

Species:

rabbit

Quality of whole database:

The available information comprises adequate, reliable (Klimisch score 2) and consistent studies, and is thus sufficient to fulfil the standard information requirements set out in Annex VIII-IX, 8.6, of Regulation (EC) No 1907/2006.

System:

urinary

Organ:

kidney

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Reliable short-term, subchronic and chronic studies regarding repeated dose toxicity are available for the test substance.

Oral:

16-day subacute oral toxicity study in the rat

The potential toxicity of the test substance was assessed in a 16-day subacute oral toxicity study in F344/N rats (National Toxicology Program, Report No. 424, 1994). Groups of 5 male and 5 female rats were administered the test substance in corn oil by gavage at doses of 0, 62.5, 125, 250, 500, or 1000 mg/kg bw/day 5 days per week over a 16-day period. Observations for clinical signs and mortality were made daily. Animals were weighed at study initiation, on day 7 and at study termination. All animals were subjected to gross pathological examination after sacrifice. Organ weights of the brain, heart, right testis, liver, lung, right kidney and thymus were determined. Histopathological examinations were performed on all gross lesions and tissue masses as well as on selected organs of all animals found dead or killed moribund during the study and all high dose animals. At 1000 mg/kg bw/day 2/5 females died and mortalities were considered treatment-related. The mean body weight gains of the animals administered 1000 mg/kg bw/day were significantly lower compared to controls. Clinical findings in the highest dose group included diarrhoea and rough hair coat. Absolute and relative kidney weights were significantly increased in males at ≥ 125 mg/kg bw/day and in females at 1000 mg/kg bw/day. Absolute and relative thymus weights were significantly decreased in males at ≥ 500 mg/kg/day and in females at ≥ 250 mg/kg/day. Relative brain and right testis weight of high dose males were significantly greater in conjunction with their decreased mean body weight. Gross necropsy revealed a dose-related dilatation of the caecum that was histopathologically associated with necrosis of the mucosal epithelium. Additionally, mild to moderate nephropathy was observed in all rats at 1000 mg/kg bw/day and myocardial degeneration was noted in 8/10 rats in this group. Thus, under the conditions of the study, the NOAEL over a 16 day period of oral administration of the test substance to the rat via gavage was 62.5 mg/kg bw/day.

 

16-day subacute oral toxicity study in the mouse

The potential toxicity of the test substance was assessed in a 16-day subacute oral toxicity study in B6C3F₁mice (National Toxicology Program, Report No. 424, 1994). Groups of 5 male and 5 female mice were administered the test substance in corn oil by gavage at doses of 0, 62.5, 125, 250, 500, or 1000 mg/kg bw/day 5 days per week over a 16-day period. Observations for clinical signs and mortality were made daily. Animals were weighed at study initiation, on day 7 and at study termination. All animals were subjected to a gross pathological examination after sacrifice. Organ weights of the brain, heart, right testis, liver, lung, right kidney and thymus were determined. Histopathological examinations were performed on all gross lesions and tissue masses as well as on selected organs of all animals found dead or killed moribund during the study and all high dose animals. No treatment-related effects on any parameter were observed 62.5 and 125 mg/kg bw/day. At 1000 mg/kg bw/day 5/5 females and 3/5 males died. No effects on body weights were observed. Clinical findings in the highest dose group included rough hair coat and postural changes. Absolute and relative liver weights were significantly increased in males at ≥ 500 mg/kg bw/day and in females at 500 mg/kg bw/day (highest dose groups were females survived). Absolute liver weight was also increased in females at 250 mg/kg bw/day. Gross necropsy revealed a dilatation of the caecum. Nephropathy was observed in mice at 500 mg/kg bw/day (2/10 animals) and at 1000 mg/kg bw/day (6/10 animals). Thus, under the conditions of the study, the NOAEL over a 16 day period of oral administration of the test substance to the mouse via gavage was 250 mg/kg bw/day.

 

21-day subacute oral toxicity study in the dog

The potential toxicity of the test substance was assessed in a 21-day subacute oral toxicity study in newborn purebred Beagle dogs (Nelson, 1973). Groups of 6 dogs were administered the test substance in corn oil by gavage at doses of 0, 3, 10, 30 or 100 mg/kg bw/day for 21 days. Observations for clinical signs and mortality were conducted daily. Animals were weighed at study initiation and daily thereafter. Blood samples for haematological and clinical chemistry examinations were collected after 10 and 20 days from all animals. All animals were subjected to gross pathological examination after sacrifice. Organ weights of the brain, heart, liver, kidneys, spleen, gonads, adrenal glands, thyroid gland and pituitary gland were determined. Histopathological examinations were performed on selected organs of all animals. One male treated with 30 mg/kg bw/day and one male treated with 100 mg/kg bw/day died after 7 days. A further male treated with 30 mg/kg bw/day died after 17 days. The causes of death were not apparent. At 100 mg/kg bw/day overall body weight gains were slightly decreased compared to control pups. No effects on haematologic and clinical chemistry parameters, on organ weights as well as on gross and histopathological findings were observed. Thus, under the conditions of the study, the NOEL over a 21 day period of oral administration of the test substance to the dog via gavage was 30 mg/kg bw/ day.

 

13-week subchronic oral toxicity study in the rat

The potential toxicity of the test substance was assessed in a 13-week subchronic oral toxicity study in F344/N rats. Groups of 10 male and 10 female rats were administered chlorophene in corn oil by gavage at doses of 0, 30, 60, 120, 240, or 480 mg/kg bw/day 5 days a week for 13 weeks. Clinical findings were recorded weekly. The animals were weighed at study initiation, weekly, and at the end of the study. Urine was collected during week 12 from rats for urinalysis. At study termination, blood was collected for haematology and clinical chemistry evaluations. Neurobehavioral studies were performed on all rats prior to the start of the 13-week study and immediately following week 13. The neurobehavioral tests conducted included spontaneous motor activity, grip strength, startle response, and analgesia. Necropsy and a complete histopathologic examination were performed on all animals. The brain, heart, right kidney, liver, lung, right testis, and thymus of rats were weighed. At doses of 30, 60 and 480 mg/kg bw/day 1/10 male rat died in each group; 3/10 males died at 120 mg/kg bw/day. Mortalities were attributed to gavage trauma and not treatment-related. No mortality occurred in females. No effects on the body weight of the rats were observed. Clinical findings included a red-yellow staining of the urogenital region hair coat of dosed females, which increased in intensity and in incidence with dose. High-dose males had brown discoloration of the hair coat around the penis (4/10 animals). Alopecia of the head (dosed females only) and transient diarrhoea (high-dose males only) were other notable clinical findings. Neurobehavioral tests indicated no significant difference among the groups for motor activity, startle response, or grip strength. A minor effect on analgesia was noted for female rats in the 480 mg/kg bw/day group. The biological significance of this effect is questionable due to the lack of pre-test reference values, a lack of similar effect on males, and the unusually high score noted for control females. Clinical chemistry examination revealed statistically significant dose-related increased albumin/globulin ratios in male rats at ≥ 240 mg/kg bw/day corresponding to net decreases in total globulin. Further effects included reduced blood urea nitrogen, bilirubin, AST, ALT, and sorbitol dehydrogenase values. Clinical pathology values for female rats were similar to the control values. Urinalysis parameters in dosed rats were similar to those of the controls. Absolute and relative kidney weights were significantly greater and absolute and relative thymus weights were significantly lower in male and female rats at 480 mg/kg bw/day as well as in female rats at 240 mg/kg bw/day. No treatment-related gross lesions were found at necropsy. Histopathological examination of the kidney revealed tubule dilatation with flattening of tubule epithelium, presence of tubule hyaline casts, and a few foci of mononuclear cells in the renal cortex interstitium. There seems to be a dose-related increase in both incidence and severity of nephropathy in male rats at ≥ 30 mg/kg bw/day, although the severity of the nephropathy was minimal to mild at these doses. At higher doses the nephropathy was mild to moderate in severity in the 240 mg/kg bw males and in the 480 mg/kg bw males and females. The incidence of nephropathy was significantly increased in male rats at ≥ 120 mg/kg bw/day as stated in Birnbaum et al., 1986 (in the Discussion). Very few of the concurrent vehicle controls animals in the current study did develop nephropathy (1/10 males) during the study. Historical control data supporting an assumption for non-significance are not provided. Thus, under the conditions of the study, the NOAEL over a 13-week period of oral administration of the test substance to the rat via gavage was 60 mg/kg bw/day.

 

90-day subchronic oral toxicity study in the dog

The potential toxicity of the test substance was assessed in a 90-day subchronic oral toxicity study in purebread beagle dogs (Nelson, 1973). Groups of 4 male and 4 female dogs were administered chlorophene orally via gelatine capsule at doses of 0, 10, 30, 100 or 200 mg/kg bw/day for 90 days. After 14 days of testing, the 200 mg/kg bw/day level was discontinued owing to severe body weight losses and animals were sacrificed after 14 days of administration. Observations for clinical signs and mortality were conducted daily. Body weights and food consumption were noted weekly. Blood and urine samples for haematological and clinical chemistry examinations as well as urinalysis were collected prior to the inception of the study, after 45 and after 90 days from all animals. All animals were subjected to a gross pathological examination after sacrifice. Organ weights of the brain, heart, liver, kidneys, spleen, gonads, adrenal glands, thyroid gland and pituitary gland were determined. Histopathological examinations were performed on selected organs of all animals. No mortalities occurred during the study. Body weight gains of dogs treated with 100 mg/kg bw/day were decreased throughout the study. No effects on overall food consumption were observed. Blood analyses revealed no significant abnormalities at 10, 30 or 100 mg/kg bw/day dose levels. Urinalysis revealed a reduced specific gravity at 100 mg/kg bw/day. This can indicate reduced tubular water re-resorption. The effect was noted after 90 days of treatment, but not after 45 days. No other kidney-related parameters were affected (histopathology, blood urea nitrogen, albumin, glucose, sediment). Absolute kidney weights were significantly increased in males at 100 mg/kg bw/day. Kidney weights relative to body weight were significantly increased in males at ≥ 30 mg/kg bw/day and in females at 100 mg/kg bw/day. Kidney weights relative to brain weight were significantly increased in males and females at 100 mg/kg bw/day. Kidney weights relative to brain weight were significantly decreased in females at 30 mg/kg bw/day. However, this effect is incidental and without biological significance. The kidney effects were not associated with microscopical abnormalities, but urine specific gravity was reduced at 100 mg/kg bw/day in both sexes. Thus, under the conditions of the study, the NOAEL over a 90 day period of oral administration of the test substance to the dog via capsule was 10 mg/kg bw/day.

                                                                                                                 

13-week subchronic oral toxicity study in the mouse

The potential toxicity of the test substance was assessed in a subchronic oral toxicity study in B6C3F₁mice (National Toxicology Program, Report No. 424, 1994). Groups of 10 male and 10 female mice were administered the test substance in corn oil by gavage at doses of 0, 30, 60, 120, 240, or 480 mg/kg bw/day 5 days a week for 13 weeks. Since no effects on survival (two mice were accidently killed), clinical signs, body weights and histopathological findings were observed, a second study with higher concentrations was performed. In the second study groups of 15 male and 15 female mice were administered the test substance in corn oil by gavage at doses of 0, 500, 650, 800 or 1000 mg/kg bw/day 5 days a week for 13 weeks. 5 animals per sex and dose group were evaluated after 2 weeks. Clinical findings were recorded weekly. The animals were weighed at study initiation, weekly, and at the end of the studies. At day 30 and at study termination of the first study, blood was collected for haematology and clinical chemistry evaluations. No clinical pathology evaluations were performed on the mice in the second study. Gross pathology examinations were only conducted on mice in the second study. A complete histopathologic examination was performed on all animals. The brain, heart, right kidney, liver, lung, right testis, and thymus of all mice were weighed. Survival of the mice in the second study decreased dose-related: 1/10 female died at 500 mg/kg bw/day, 2/10 males and 1/10 female died at 650 mg/kg bw/day, 6/10 males and 8/10 females died at 800 mg/kg bw/day and 9/10 males and all females died at 1000 mg/kg bw/day. Mean body weight gains were statistically significantly decreased in males of all dose groups and in females at 500 and 800 mg/kg bw/day. Treatment-related clinical findings in mice of both sexes at ≥ 650 mg/kg bw/day included hypoactivity and a rough or oily hair coat. Absolute and relative liver weights were statistically significantly increased in males at 800 mg/kg bw/day and in females at 500, 650 and 800 mg/kg bw/day. Absolute and relative kidney weights were statistically significantly decreased in males at 500, 650 and 800 mg/kg bw/day. Significant microscopic lesions observed in all dose groups included a time- and dose-related increased incidence of and severity of nephropathy, which consisted of renal tubule cell necrosis, luminal casts, tubule regeneration and mononuclear inflammatory cells in the renal cortical interstitium. Nasal lesions, considered to be caused by the caustic nature of the test substance following retrograde exposure after gavage consisted of an acute, necrotizing, suppurative inflammation of the olfactory epithelium. Thus, under the conditions of this study, the LOAEL over a 13 week period of oral administration of the test substance to the mouse via gavage was 500 mg/kg bw/day.

 

2 year chronic oral toxicity study in the rat

The potential toxicity of the test substance was assessed in a 2 year chronic oral toxicity study combined with carcinogenicity study in F344/N rats (National Toxicology Program, Report No. 424, 1994). Groups of 80 male and 80 female rats were administered the test substance in corn oil by gavage at doses of 0, 30, 60 or 120 mg/kg bw/day (males) or 0, 60, 120 or 240 mg/kg bw/day (females) 5 days a week. 10 rats per sex and dose group were sacrificed after 13 weeks for interim evaluation. 10 rats per sex and dose group were sacrificed after 65 weeks for interim clinical pathology and histopathological examinations. All remaining animals were sacrificed after 104 weeks. The duration of the final undosed interval was 10-12 days for the 104 week scheduled termination. Animals were observed twice daily and clinical findings were recorded weekly. Body weights were determined at study initiation, weekly for the first 13 weeks, and monthly thereafter. Food consumption was measured monthly. Blood and urine samples were collected from all animals designated to the 13 and 65 week interim sacrifice at respective study termination for haematological and clinical chemistry examinations as well as urinalysis. At interim sacrifices organ weights of brain, heart, kidneys, liver, lung, right testis and thymus were determined. Gross pathological examinations were performed on all animals. Histopathological examinations were performed on all tissues with grossly visible lesions and on all animals killed moribund. At the 13 and 65 week interim sacrifices a complete histopathology was performed on all rats of the control and high dose group. At study termination a complete histopathology was performed on all rats. Survival of dosed male and female rats was similar to that of the controls. Mean body weights of dosed rats were generally similar to those of the controls. No chemical-related clinical findings were observed except yellow staining of the urogenital area hair coat in dosed female rats which was considered to be treatment-related (0 mg/kg bw/day: 9/80 females; 60 mg/kg bw/day: 66/80 females; 120 mg/kg bw/day: 69/80 females; 240 mg/kg bw/day: 77/80 females). Kidney weights were increased in a time- and dose-dependent manner with males as the most sensitive sex. At the 13-week interim evaluation, absolute and relative kidney weights were significantly increased in males receiving 120 mg/kg bw/day and females receiving 240 mg/kg bw/day. Microscopic lesion related to compound administration at the 13-week evaluation was nephropathy in female rats, for which the incidence and severity increased with dose. At the 65-week interim evaluation, absolute kidney weights were greater in all dosed male groups and absolute and relative kidney weights were significantly greater in mid- and high-dose females compared to the controls.Nephropathy was present in essentially all rats after 64 weeks of chemical administration; however, nephropathy increased in severity with dose and was more severe in male than in female rats. At study termination, relative kidney weights were increased in all dosed males and in females of the mid- and high dose groups. Severe, time- and dose-related nephropathy was observed in male and female rats, occurring as early as 3 months after the beginning of chemical administration (females). The nephropathy was characterized by tubule dilatation, flattening of the tubule epithelium, and the presence of regenerative tubules surrounded by a thickened basement membrane. With increased severity, the prominent dilated tubules contained hyaline casts and cellular debris. More advanced lesions were characterized by additional alterations of interstitial fibrosis, multiple interstitial foci of mononuclear cells, foci of mineralization, and degenerative changes with sclerosis of glomeruli. The dose-related increase in severity was particularly striking in high-dose female rats because of the usual minimal severity of spontaneous nephropathy in control female rats. The severity of the nephropathy was significantly increased in a time- and dose-dependent manner both in males and females, with males being the most sensitive sex. In male rats dosed for as long as 2 years, secondary hyperparathyroidism developed, with parathyroid gland hyperplasia, mineralization of the kidney and glandular stomach, and fibrous osteodystrophy occurring in the high-dose group. The kidney was the only organ in which chemical- related increased incidences of neoplasms may have occurred. One renal tubule adenoma occurred in a control male rat, one renal tubule adenoma and one transitional cell carcinoma occurred in high-dose female rats, and one transitional cell carcinoma occurred in a mid-dose female. One renal tubule carcinoma was observed in a high-dose male rat. Thus, under the conditions of this study, the males were more sensitive compared to females and the LOAEL was 60 mg/kg bw/day for males. Thus, no NOAEL could be established for the males. The NOAEL for female rats over a 104 week period of oral administration of the test substance to the rat via gavage was 60 mg/kg bw/day.

 

2 year chronic oral toxicity study in the mouse

The potential toxicity of the test substance was assessed in a 2 year chronic oral toxicity study combined with carcinogenicity study in B6C3F₁mice (National Toxicology Program, Report No. 424, 1994). Groups of 70 male and 70 female mice were administered the test substance in corn oil by gavage at doses of 0, 120, 240 or 480 mg/kg bw/day 5 days a week. 10 mice per sex and dose group were sacrificed after 13 weeks for interim evaluation. Further 10 mice per sex and dose group were sacrificed after 65 weeks. All remaining animals were sacrificed after 104 weeks. Animals were observed twice daily and clinical findings were recorded weekly. Body weights were determined at study initiation, weekly for the first 13 weeks, and monthly thereafter. Food consumption was recorded weekly. At interim sacrifices organ weights of brain, heart, kidneys, liver, lung, right testis and thymus were determined. Gross pathological examinations were performed on all animals. Histopathological examinations were performed on all tissues with grossly visible lesions and on all animals killed moribund. At the 13 and 65 week interim sacrifices a complete histopathology was performed on all mice of the control and high dose group. At study termination a complete histopathology was performed on all mice. Survival of dosed male and female rats was decreased compared to that of the controls. The probability of survival for dosed males ranged from 64 – 81% (control 90%). The probability of survival for females of the highest dose group was significantly lower (51%) compared to that of the controls (74%). Renal disease was considered a significant factor in the decreased survival of male and female mice. Mean final body weights were statistically significantly lower in males at all dose groups and females of the mid and high dose compared to control animals. Decreased body weights (by 10%) were apparent from weeks 28, 68 and 84 for males dosed at 120, 240 and 480 mg/kg bw/day, respectively. In females dosed at 240 and 480 mg/kg bw/day a 10% lower mean body weight compared to controls occurred from weeks 93 and 26, respectively. Treatment-related clinical signs included emaciation, abnormal posture, rough hair coat and hypoactivity. No effect on food consumption was observed. At the 3-month interim evaluation, nephropathy was observed in treated animals of both sexes with dose-related incidence and severity (more severe in males; severity grades based on the extent of parenchymal involvement). Kidney weights of high dose males were significantly decreased. Microscopic lesions were confined to the kidney and included multiple foci of dilated tubules with a flattened epithelium, a few tubules with hyaline casts, regenerated tubules with basophilic epithelium, a few necrotic tubules with neutrophils and debris in the lumen and foci of mononuclear cells in the renal cortical interstitium. Additionally, significantly increased absolute and relative liver weights were observed in high dose males and females after 13 weeks of treatment. At the 65-week interim evaluation, spontaneous nephropathy in control males increased and, thus, incidences in dosed males was similar to controls. The incidence of nephropathy in dosed females increased. In contrast to the male control animals no increase in nephropathy incidence was observed in control females. However, a dose-related increase in severity occurred in both, dosed males and females. Absolute and relative kidney weights of treated males as well as absolute kidney weights of treated females were statistically significantly decreased compared to corresponding control animals. With regard to macroscopic lesions affected kidneys, particularly in males, were pale, tan and/or granular. Correspondingly, histopathology revealed multifocal dilatation of renal tubules with flattening of the tubule epithelium, luminal hyaline casts and cellular debris, thickened tubule basement membranes, tubule cell necrosis, regeneration of tubule cells and infiltrates of mononuclear cells in the renal cortical interstitium. Absolute and relative liver weights were significantly increased in high dose females after 65-week of treatment. At the end of the 2 year study, proliferative lesions were observed in the kidneys of treated males (renal tubule hyperplasia in mid and high dose males, renal tubule adenoma and carcinoma). At 240 mg/kg bw/day and 480 mg/kg bw/day the incidence of neoplasia was statistically significantly increased (0 mg/kg bw/day: 0/50 males; 120 mg/kg bw/day: 2/50 males; 240 mg/kg bw/day and 480 mg/kg bw/day: 6/50 males). Additionally, a dose-related increased incidence in hyperplasia of the forestomach was observed in female mice probably related to an irritant effect of the test substance. Incidence was also increased in treated males but without dose relation. Treatment-related lesion occurring in males and females was focal mucosal ulceration of the forestomach. This effect might also be attributed to the irritant properties of the test substance or might occur secondary to nephropathy. Further findings (mineralization of the glandular mucosa with focal gastric and duodenal ulcers (all dosed groups of males and females), myocardial degeneration (mid- and high-dose males) and focal coagulative necrosis of the liver (high-dose females)) were considered to be secondary to the combined disturbances of nephropathy and an associated secondary hyperparathyroidism. Thus, under the conditions of this study, the LOAEL over a 104 week period of oral administration of the test substance to the mouse via gavage was 120 mg/kg bw/day; no NOAEL could be assessed.

 

Dermal:

21-day subacute dermal toxicity study in the rabbit

The potential toxicity of the test substance was assessed in a 21-day subacute dermal toxicity study in the New Zealand White rabbit performed according to US EPA Guideline 8.22 and similar to OECD Guideline 410 as well as in compliance with GLP (Cummins, 1985). Groups of 7 male and 7 female rabbits received daily 6-h applications of 0, 4, 20, or 100 mg test substance/kg bw/day for 21 consecutive days under occlusive conditions. The test substance was formulated in 50% ethanol in water. Observations for moribundity were conducted three times daily. Animals were checked once daily before treatment for clinical signs of toxicity, including skin reactions. Individual body weights were determined before start of treatment and weekly thereafter. Food consumption was recorded once per week and water-intake was visually inspected daily. Blood samples for haematology and clinical chemistry examination were collected one week before treatment and after two weeks of treatment. All animals were subjected to a detailed necropsy. Organ weights of the brain, heart, testes (paired), liver, kidneys (paired), ovaries, pituitary, thyroid/parathyroid and adrenals (paired) were determined. Histopathological examinations were performed on 5 animals per sex of control and high dose group. In addition, skin thickness was measured of all animals of the control and high dose group from the 4th application until study termination after removal of the test substance. A total of 14 animals died during the treatment period (0 mg/kg bw/day: 2/14; 4 mg/kg bw/day: 2/14; 20 mg/kg bw/day: 5/14; 100 mg/kg bw/day: 5/14) increasing in numbers with increased exposure. No effects on body weight or food consumption were observed. Kidney and liver lesions were rather more common among decedents which had been treated with the test substance. A higher number of female rabbits had kidney lesions at the time of death (dead/killed during treatment period + sacrificed at the end of the study) in the highest dose group, and there was a tendency towards more severe kidney lesions in the 100 mg/kg bw/day group compared to the control group. At 100 mg/kg bw/day alkaline phosphatase activity (ALP) was significantly decreased in females. Local reactions to treatment with the test substance were observed at ≥ 20 mg/kg bw/day. Thus, under the conditions of the study, the NOAEL for systemic toxicity over a 21-day period of dermal administration with the test substance to the rabbit was 20 mg/kg bw/day. In terms of local effects the NOAEL was 4 mg/kg bw/day.

 

21-day subacute dermal toxicity study in the rabbit

The potential toxicity of the test substance was assessed in a 21-day subacute dermal toxicity study in the New Zealand White rabbit performed in compliance with GLP (Krötlinger and Karbe, 1985). Groups of 7 male and 7 female rabbits received 6-h applications of 0, 10, 40, or 160 mg test substance/kg bw/day 5 days per week for 21 consecutive days under non-occlusive conditions. A satellite group was also treated with 160 mg/kg bw/day. The animals of this group (7/sex/dose) were observed for a further 2 weeks without substance application after the end of the three week treatment period. The test substance was formulated in polyethylene glycol.Observations for clinical signs including effects on the skin and moribundity were conducted twice daily (once daily on weekends and holidays). Individual body weights and food consumption were recorded weekly. Blood samples for haematology and clinical chemistry examination were collected3 week after the start of treatment in 5 animals per sex and dose group as well as 2 weeks after the end of treatment in the animals of the satellite group. Urinalysis was performedin 5 animals per sex and dose groupat the end of treatmentas well as 2 weeks after the end of treatment in the animals of the satellite group. All animals which died or were sacrificed moribund during the study period as well as 5 surviving animals per sex and dose group weresubjected to a macroscopical examination.Organ weights of the heart, testes, lung, liver, spleen, kidneys, thyroid and adrenals were determined. Histopathological examinations were performed onall animals of control and high dose group. A dose-dependent increase in histopathological changes in the kidneys of female rabbits was observed after dermal application of ≥ 40 mg/kg bw/day of the test substance. The observed histopathological changes included tubular calcinosis, tubular proliferation and cellular infiltration. In conjunction with observed spontaneous changes in the brain, kidney lesions might suggest the presence of nosematosis. However, based on the dose-dependent increase in histopathological kidney effects and kidney being target organ the effects are considered treatment-related.The test substance was further observed to have effects on the liver of female animals at a dosage of 160 mg/kg bw/day. In view of the lower activities of the alkaline phosphatase, lower liver weights and the histopathologically established reduced liver cell storage (probably of glycogen) detected only in female rabbits of the 160 mg/kg bw/day group, a treatment-related effect on the liver cannot be excluded. The livers of the female animals were still lighter in weight at the end of the restitution phase. From the dosage 40 mg/kg/ bw/day, the test substance had a severe skin irritant effect. The skin lesions were reversible. There were no effects of treatment on behaviour, mortality, urinalysis, haematology, or gross pathology. Thus, under the conditions of the study, the NOAEL for systemic toxicity over a 21-day period of dermal administration with the test substance to the rabbit was 10 mg/kg bw/day. In terms of local effects the NOAEL was 10 mg/kg bw/day.

 

21-day subacute dermal toxicity study in the rabbit

The potential toxicity of the test substance was assessed in a 21-day subacute dermal toxicity study in the New Zealand White rabbit performed according to US EPA Guideline 8.22 as well as in compliance with GLP. Groups of 7 male and 7 female rabbits received daily 6-h applications of 0, 1, 5 or 25 mg test substance/kg bw/day for 21 consecutive days under occlusive conditions. The test substance was formulated in 50% ethanol in water.Observations for moribundity were conducted three times daily. Animals were checked once daily before treatment for clinical signs of toxicity, including skin reactions. Individual body weights were determined before start of treatment, twice weekly thereafter and before necropsy. Food consumption was recorded once per week. Blood samples for haematology and clinical chemistry examination were collected 5 days before study initiation and after 3 weeks of treatment. All animals weresubjected to a detailed necropsy.Selected organ weights were determined. Histopathological examinations were performed onall animals of control and high dose group. No effects on mortality, clinical signs, body weights and food consumption were observed. Local signs of reaction were observed on the skin of animals treated with 25 mg/kg bw/day and of occasional animals treated with 5 mg/kg bw/day. No treatment-related findings on haematological or clinical chemistry parameters as well as on organ weights were noted. Regardless of skin lesions observed in the highest dose group, no treatment-related changes were recorded during macroscopic examination or histopathological examination. Thus, under the conditions of the study, the NOAEL for systemic toxicity over a 21-day period of dermal administration with the test substance to the rabbit was ≥ 25 mg/kg bw/day. In terms of local effects the NOAEL was 1 mg/kg bw/day.

Justification for classification or non-classification

The available data on repeated dose toxicity meet the criteria for classification according to Regulation (EC) 1272/2008. The test substance is classified as STOT RE Category 2, H373 (kidney): May cause damage to the kidney through prolonged or repeated exposure.

In fact, this is further in line with the conclusion of the ECHA Committee for Risk Assessment (RAC) Opinion for harmonised EU classification and labelling of Chlorophene based on the same reliable data, which was adopted in 2015 ( RAC CLH-O-0000001412-86-58/F, 12 March 2015). As a result, and referring to the Adaptation to Technical Progress (ATP) to CLP Regulation, Chlorophene was inserted in ATP10 with following classification and labelling for repeated dose toxicity: STOT RE 2, H373 (kidney).