Benzyl-C12-14-alkyldimethylammonium chlorides

Carcinogenicity

Description of key information

The available chronic carcinogenicity studies with the read across substance in rats indicate no concern for carcinogenicity for the test substance. 

Key value for chemical safety assessment

Carcinogenicity: via oral route

Link to relevant study records

Reference

Reference 1

Endpoint:

carcinogenicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

KL2 due to RA

Justification for type of information:

Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification.

Qualifier:

according to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

yes

Remarks:

not considered to have compromised the validity or integrity of the study

Principles of method if other than guideline:

There were following deviations to the protocols:
- the temperature and relative humidity in the animal room were sometimes out of the target ranges
- the analysis of the dietary concentrations was performed in excess in week 104.
- for female D29585, only one sampled of mass was performed instead of two for masses 2110, 2118 and 1205
- for male D29335, because of a technical problem, macroscopic examination was performed after fixation with a pathologist
- rectum was not sampled for female D29626.
These deviations were not considered to have compromised the validity or integrity of the study.

GLP compliance:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Route of administration:

oral: feed

Duration of treatment / exposure:

2 year

Remarks:

Doses / Concentrations:
0, 1000, 2000, 4000 ppm of test substance (i.e., equivalent to 0, 500, 1000 and 2000 ppm of active substance)
Basis: nominal in diet

No. of animals per sex per dose:

- 20 males and 20 females of each group were used for toxicological investigations and were treated for 52 weeks.
- 50 males and 50 females of each group were used to investigate the carcinogenic potential and were treated for 104 weeks.
- A group of 60 male and 60 female rats received untreated diet under the same experimental conditions, and acted as toxicology (10 males and 10 females) and carcinogenicity (50 males and 50 females) control group.

Control animals:

yes, plain diet

Details on study design:

Post-exposure period: None

Observations and examinations performed and frequency:

- Animals were checked at least twice daily for mortality and clinical signs. In addition, detailed clinical observations were made once a week. After 6 months of treatment, all animals were palpated every 2 weeks in order to record the time of onset, location, size, appearance and progression of palpable masses. Body weights were recorded once during the pre-treatment period, on Day 1 and then once a week during the first 13 weeks of the treatment period and then once every 4 weeks until the end of the study. Food consumption was recorded once a week during the first 13 weeks of the study, and then over 7-d periods once every 3 months between weeks 14 and 25, and thereafter once per month until the end of the study.
- Haematological, blood biochemical investigations and urinalysis were performed on all surviving animals of the toxicology sub-groups in weeks 12, 26 and 52. During weeks 52, 78 and 104, differential white blood cell counts were determined for all surviving animals of the control and high-dose carcinogenicity sub-groups.

Sacrifice and pathology:

Surviving animals were killed at the end of the 52-week treatment period for the toxicology sub-groups and at the end of the 104-week treatment period for the carcinogenicity sub-groups. All animals were submitted for a full macroscopic post-mortem examination. Designated organs were weighed and selected tissue specimens were preserved. A microscopic examination was performed on all masses, and on designated tissues of animals from the control sub-groups and from the sub-groups treated at 4000 ppm of test substance sacrificed at the end of the 52 or 104-week treatment periods, and from all animals that died prematurely.

Clinical signs:

no effects observed

Description (incidence and severity):

In the toxicology sub-groups: No treatment-related clinical signs were observed during the 52-week treatment period
In the toxicology sub-groups: No test substance-related clinical signs were observed in any treated group

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

In the toxicology sub-groups: No treatment-related deaths or premature sacrifices occurred during the 52-week treatment period
In the carcinogenicity sub-groups: Survival rate in animals treated with the test substance was not statistically different from to controls. Further, mortality was comparable in terms of time of occurrence and cause

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

In the toxicology sub-groups: The mean body weight was significantly lower in the males treated at 4000 ppm than in the controls from week 2 to week 50, due to a lower body weight gain over all the study (from -15% between weeks 0 and 4, to finally -21% between weeks 0 and 50). This lower body weight gain was attributable to a slightly to moderately lower food consumption (ranging from 73.3 to 94.4% of that of controls over the toxicology study), with statistically significant differences occurring during several weeks
In the carcinogenicity sub-groups: The mean body weight was significantly lower in the males and females treated at 4000 ppm than in the controls from week 2 to week 13, due to a lower body weight gain (-14% and -10% for males and females, respectively). This lower body weight gain was attributable to slightly to moderately lower food consumption compared with controls, with statistically significant differences occurring during several weeks. From week 13 to termination, the body weight of the males treated at 4000 ppm was still significantly lower than that of control animals, and this was correlated to a 18% lower body weight gain over the 104 weeks when compared with controls, while the body weight and body weight gain of all other treated animals were in the range of control values

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

In the toxicology sub-groups: Slightly to moderately lower food consumption (ranging from 73.3 to 94.4% of that of controls over the toxicology study), with statistically significant differences occurring during several weeks
In the carcinogenicity sub-groups: Slightly to moderately lower food consumption compared with controls, with statistically significant differences occurring during several weeks. F

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Description (incidence and severity):

In the toxicology sub-groups: Haematological parameters were not affected by the treatment at any dose-level

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

In the toxicology sub-groups: Blood biochemistry parameters were not affected by the treatment at any dose-level
In the carcinogenicity sub-groups: There were no significant differences in the differential white blood cell parameters of males and females treated at 4000 ppm, when compared with controls, whatever the sampling time (weeks 52, 78 and 104)

Urinalysis findings:

no effects observed

Description (incidence and severity):

In the toxicology sub-groups: Urinalysis parameters were not affected by the treatment at any dose-level

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Description (incidence and severity):

In the carcinogenicity sub-groups: There were no differences in the number and localization of palpable masses in test-treated animals and controls

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

In the toxicology sub-groups: There were no relevant histopathological findings
In the carcinogenicity sub-groups: No non-neoplastic lesions were found which were considered to represent a treatment-related effect

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

In the carcinogenicity sub-groups: The administration of the test substance did not induce neoplastic changes under the conditions of this study

Key result

Dose descriptor:

NOEL

Remarks:

carcinogenicity

Effect level:

ca. 4 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no substance related carcinogenic effects

Remarks on result:

other: equivalent to 2000 ppm active substance

Remarks:

equivalent to 97 and 119 mg a.i./kg bw/day for male and female respectively

Key result

Dose descriptor:

NOEL

Remarks:

systemic effects

Effect level:

ca. 2 000 ppm

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: Lower body weight gain at 4000 ppm test substance (significant only in males of 52 week chronic study part; significant in males and females in 104 week carcinogenicity group)

Remarks on result:

other: equivalent to 1000 ppm active substance

Key result

Dose descriptor:

LOAEL

Remarks:

systemic effects

Effect level:

ca. 4 000 ppm

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: equivalent to 2000 ppm active substance

Key result

Critical effects observed:

no

For result tables, kindly refer to the attached background material section of the IUCLID.

Conclusions:

Under the study conditions, the read across substance was not carcinogenic following chronic dietary administration up to 4000 ppm (i.e., equivalent to 97 and 119 mg a.i./kg bw/day for male and female respectively) in SD rats for two years.

Executive summary:

A study was conducted to determine the carcinogenicity of the read across substance, C12 -16 ADBAC (purity: 49.2 -49.9%) according to OECD Guideline 453, in compliance with GLP. The substance was administered daily to Sprague-Dawley rats by dietary admixture at the concentrations of 1000, 2000 and 4000 ppm (equivalent to 500, 1000 and 2000 ppm a.i.) for 52 weeks (toxicology sub-group) and 104 weeks (carcinogenicity sub-group; corresponding to 24, 48 or 97 mg a.i./kg bw/day for males and 29, 58 or 119 mg a.i./kg bw/day for females). No treatment-related tumorigenic effects were observed. Under the study conditions, the read across substance was not carcinogenic following chronic dietary administration up to 4000 ppm (equivalent to 97 and 119 mg a.i./kg bw/day for males and females, respectively) in SD rats for two years (Appelqvist, 2007). Based on the results of the read across study, similar results can be expected for the test substance.

Reference 2

Endpoint:

carcinogenicity: oral

Type of information:

read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Study period:

From March 22, 1988 to July 08, 1991

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification.

Qualifier:

according to guideline

Guideline:

OECD Guideline 453 (Combined Chronic Toxicity / Carcinogenicity Studies)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.4300 (Combined Chronic Toxicity / Carcinogenicity)

Deviations:

no

GLP compliance:

yes

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

Test animals:
- Source: Sprague-Dawley CD rats were obtained from Charles River Breeding Laboratories, Portage MI USA
- Age at study initiation: 8 weeks
- Weight at study initiation: 246.9-308.7 g (males) and 161.8-215.1 g (females)
- Housing: The animals were housed one animal/cage in divided stainless steel cages (solid sides with three mesh floors) mounted in a stainless steel Maxi-Rack (Hazleton Systems, Inc., Aberdeen, MD).
- Diet: Ground Purina Certified Rodent Chow # 5002 (Ralstor Purina Co., St. Louis, MO), ad libitum
- Water: Municipal water, ad libitum. Water was provided by an automatic watering system with demand control valves mounted on each rack.
- Acclimation period: One week

Environmental conditions
- Temperature: 66-77 °F
- Humidity: 40-70%
- Air changes: 8/h
- Photoperiod: Fluorescent lighting was provided 12 h/d using an automatic timer.

In-life dates: From: 22 March 1988 to: 27 March 1990

Route of administration:

oral: feed

Vehicle:

ethanol

Details on exposure:

Diet preparation: Test diets were prepared by direct addition of the test substance to ground rodent feed. A concentrated premix was prepared to ensure maximal loss of the ethanol (approximately 12% by weight) from the test substance during the original mixing time of 1h. Test diets were prepared by appropriate dilutions of the concentrated premix or higher diet concentrations.
- Rate of preparation of diet (frequency): Fresh diet was prepared and offered to the animals each week.
- Mixing appropriate amounts with (Type of food): Ground Purina Certified Rodent Chow # 5002
- Storage temperature of food: Diets were stored in polypropylene containers at room temperature.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Experimental diets were analyzed for stability, homogeneity and concentration of test substance in the diet by using liquid chromatography.
- Homogeneity studies performed on samples from all dietary concentrations indicated that test substance was uniformly distributed in the diet.
- Stability studies were conducted on diets (300 and 200 ppm) stored at room temperature in closed polypropylene containers and in glass jars. These analyses indicated that the test substance was stable in the diets for at least 14d in glass jars and stable for at least 21 d in closed polyethylene containers.
- Concentration verification analyses of 87 samples (mean of duplicate assays) for the diets revealed that the test substance concentration ranged from 92.4 to 110.0% of nominal for all 3 concentrations.

Duration of treatment / exposure:

24 months (104 weeks)

Frequency of treatment:

Daily

Post exposure period:

No

Remarks:

Doses / Concentrations:
0, 300, 1000 or 2000 ppm test substance (equivalent to mean intake levels of 0, 13, 44, and 88 mg/kg bw/day (males) and 0, 17, 57 and 116 mg/kg bw/day (females).
Basis: nominal in diet

No. of animals per sex per dose:

60

Control animals:

yes, plain diet

Details on study design:

Rationale for animal assignment: Animals considered suitable for study on the basis of pretest health screen. Evaluations for fecal parasites, clinical pathology, gross pathology, histology and serology conducted during the pretest period indicated that the animals were free of infectious disease and parasites. Animals were assigned to test groups, based on body weight, by a computer generated, weight stratified randomization procedure. Only rats with body weights within ± 20% of the population mean for each sex were used in the study.

Assignment of animals: The animals were assigned into following groups in the study:
- Group 1(Diet control): Plain diet
- Group 2 (Low dose): 300 ppm test substance in diet
- Group 3 (Mid dose): 1000 ppm test substance in diet
- Group 4(High dose): 2000 ppm test substance in diet
- Group 5 (Diet control): Plain diet

Observations and examinations performed and frequency:

MORTALITY/MORBIDITY and CLINICAL SIGNS: Yes
Time schedule: Twice daily

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Detailed clinical observations were performed once each week. Observations for overt clinical signs were made once daily on days when detailed observations were not conducted.

BODY WEIGHT: Yes
- Time schedule for examinations: Body weight data were collected weekly for the first 14 weeks and every other week thereafter.

FOOD CONSUMPTION: Yes
- Time schedule: Food consumption data were collected weekly for the first 14 weeks and every other week thereafter.

WATER CONSUMPTION AND COMPOUND INTAKE: No

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: Ophthalmologicic examinations were performed prior to study initiation and prior to final sacrifice.
- Dose groups that were examined: All animals

HAEMATOLOGY: Yes
- Time schedule for collection of blood: At 26, 52, 78, and 104 weeks of study
- Animals fasted: Yes (overnight)
- How many animals: 15 animals/sex/group at 26, 52, 78, and 104 weeks of study and on all animals prior to necropsy.
- Parameters checked: Hemoglobin, hematocrit, erythrocyte count, erythrocyte indices, platelet count, total leukocyte count, differential leukocyte count, reticulocyte count

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: At 26, 52, 78, and 104 weeks of study
- Animals fasted: Yes (overnight)
- How many animals: 15 animals/sex/group at 26, 52, 78, and 104 weeks of study and on all animals prior to necropsy.
- Parameters checked: Glucose, urea nitrogen, creatinine, AST (SGPT), ALT (SGOT), creatine kinase, gamma glutamyl transpeptidase, alkaline phosphatase, total protein, total cholesterol, albumin, globulin, A/G ratio, total bilirubin, direct bilirubin, indirect bilirubin, calcium, phosphorous, sodium, potassium, chloride.

URINALYSIS: Yes
- Time schedule for collection of urine: At 25, 51, 77, and 103 weeks of study.
- How many animals: 15 animals/sex/group at 25, 51, 77, and 103 weeks of study.
- Metabolism cages used for collection of urine: Yes
- Animals fasted: Yes
- Parameters checked: Color, appearance, specific gravity, total volume, pH, protein, glucose, ketone, bilirubin, blood, urobilirubinogen, microscopic elements.

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

SACRIFICE: Animals were anesthetized with methoxyflurane and exsanguinated by severing the brachial vessel. 
GROSS PATHOLOGY: Yes, complete gross postmortem examination was performed on all animals.
HISTOPATHOLOGY: Yes, microscopic examination was performed on all tissues from the two controls and high dose animals as well as lungs, liver, kidneys, and gross lesions in the mid and low dose groups. In addition to gross lesions and tissue masses, the following tissues were examined: spinal cord, brain, pituitary, thyroid, thymic region, trachea, lungs, heart, salivary gland, liver, spleen, kidneys, adrenals, pancreas, testes, epididymis, prostate, seminal vesicles, ovaries, uterus, vagina, mammary gland, skin, esophagus, stomach, duodenum, jejunum, ileum, cecum, colon, rectum, urinary bladder, representative lymph nodes, peripheral nerve, sternum, femur, thigh musculature, eyes and aorta. Apart from treatment-related lesions, observations were also made for any presence of neoplasm or various tumour types in different tissues.

Other examinations:

ORGAN WEIGHT: The liver, kidneys, adrenals, spleen, brain with stem, heart, testes and ovaries were weighed for all animals sacrificed at termination.

Statistics:

Parametric variables were compared between the test and control groups using Leven’s test for homogeneity of variances, by analysis of variance and by pooled variance t-tests. Non-parametric data were analyzed by the Kruskal-Wallis test or by the Wilcoxon rank sum test as modified by Mann-Whitney. Frequency data were compared using Fisher’s exact tests. Mortality and mean days to first palpable mass were analysed using life-table analyses. The two control groups were treated as independent entities for statistical or other interpretative purposes.

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

An increased incidence of loose faeces was noted in the male rats in all groups treated with the test substance. Based upon previous 14-day and 90-day dietary studies with the test substance, the increased incidence of loose faeces in this study was considered potentially treatment-related; however, the lack of a dose response relationship in incidence and the sporadic nature of the observation throughout all dose groups limited the importance of this finding. There were no other clinical signs observed in male rats considered to be treatment-related. No clinical signs observed in the female rats were considered to be related to treatment with test substance.

Dermal irritation (if dermal study):

not examined

Mortality:

mortality observed, non-treatment-related

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

The mean absolute body weights of the 2000 ppm group male and female rats were statistically significantly decreased at most measurement periods from Week 1 to Week 26 (male) and Week 1 to 60 (female) and, while not consistently statistically significant, remained decreased throughout the study. No treatment related changes were observed in the other groups.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

A transient food consumption decrease was reported in the male rats in the 1000 ppm treatment group during the first few months of the study. Mean food consumption values for the 2000 ppm dose group were generally depressed 2 to 12 % throughout the study.

Food efficiency:

not examined

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

not examined

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Description (incidence and severity):

No treatment-related effects were observed in any of the tissues examined.

Histopathological findings: neoplastic:

no effects observed

Description (incidence and severity):

No treatment-related effects were observed in any of the tissues examined. The tumour type or incidence in any tissues or organs were also not affected by the treatment.

Relevance of carcinogenic effects / potential:

No treatment-related neoplasm or increase in tumor incidence was observed in treated males and females.

Key result

Dose descriptor:

NOAEL

Remarks:

carcinogenicity

Effect level:

> 2 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: absence of any treatment related effect on any tumour type or incidence in any of the tissues examined

Remarks on result:

other: equivalent to 88 mg/kg bw/day or 71.3 mg a.i./kg bw/day in males and 116 mg/kg bw/day or 93.9 mg a.i./kg bw/day in females

Key result

Dose descriptor:

NOAEL

Remarks:

systemic toxicity

Effect level:

ca. 1 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

Key result

Critical effects observed:

no

For result tables, kindly refer to the attached background material section of the IUCLID.

Conclusions:

Under the test conditions, there was no evidence of carcinogenic activity of the read across substance in rats administered at dietary dose levels up to 2000 ppm (equivalent to 88 mg/kg bw/day or 71.3 mg a.i./kg bw/day in males and 116 mg/kg bw/day or 93.9 mg a.i./kg bw/day in females).

Executive summary:

A study was conducted to determine the carcinogenicity of the read across substance (ca. 81% active in aqueous/ethanol solution) according to OECD Guideline 453 and US EPA OPPTS 870.4300, in compliance with GLP. The experiment was performed as a two-year oral feeding study in Sprague-Dawley CD rats. The read across substance was orally administered to rats (60/sex/group) at dose levels of 0, 300, 1000 or 2000 ppm (equivalent to mean intake levels of 0, 13, 44, and 88 mg/kg bw/day in males and 0, 17, 57 and 116 mg/kg bw/day in females) in the diet daily for 104 weeks. There were two control groups of 60/sex/group each. The animals were observed twice daily, body weights and clinical findings were recorded periodically. Clinical pathology measurements (haematology, clinical chemistry and urine analysis) were made at 6, 12, 18 and 24 months. At termination, a thorough post-mortem examination was conducted on all animals. Histopathology was conducted on a full set of tissues and organs from all animals in the control and high dose groups as well as on selected organs from animals in the low and mid-dose groups. Further, examinations were also performed to evaluate any treatment-related effect on tumour type or incidence in various organs. An increased incidence of loose faeces in male rats was observed which was considered to be potentially treatment-related, however, was not of biological significance. A reduction in mean absolute body weights and food consumption was observed in males and females in the high dose group. No treatment-related effects were observed in the type or incidence of clinical signs, survival, the type or incidence of palpable masses, clinical pathology, organ weights, gross and microscopic anatomic pathology or ophthalmology. Under the test conditions, there was no evidence of carcinogenic activity of the read across substance in rats administered at dietary dose levels up to 88 mg/kg bw/day or 71.3 mg a.i./kg bw/day in males and 116 mg/kg bw/day or 93.9 mg a.i./kg bw/day in females (Gill, 1991). Based on the results of the read across study, similar results can be expected for the test substance.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

44 mg/kg bw/day

Study duration:

chronic

Species:

rat

Quality of whole database:

Exceeds the information requirements for this tonnage band.

Carcinogenicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Carcinogenicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

Based on the results of the read across chronic carcinogenicity studies in rats, the test substance does not warrant classification according to the EU CLP criteria (Regulation 1272/2008/EC).​

Additional information

Study 1:A study was conducted to determine the carcinogenicity of the read across substance, C12 -16 ADBAC (49.2-49.9% active in water) according to OECD Guideline 453, in compliance with GLP. The substance was administered daily to Sprague-Dawley rats by dietary admixture at the concentrations of 1000, 2000 and 4000 ppm (equivalent to 500, 1000 and 2000 ppm a.i.) for 52 weeks (toxicology sub-group) and 104 weeks (carcinogenicity sub-group; corresponding to 24, 48 or 97 mg a.i./kg bw/day for males and 29, 58 or 119 mg a.i./kg bw/day for females). No treatment-related tumorigenic effects were observed. Under the study conditions, the read across substance was not carcinogenic following chronic dietary administration up to 4000 ppm (equivalent to 97 and 119 mg a.i./kg bw/day for males and females, respectively) in SD rats for two years (Appelqvist, 2007).

Study 2:A study was conducted to determine the carcinogenicity of the read across substance (ca. 81% active in aqueous/ethanol solution) according to OECD Guideline 453 and US EPA OPPTS 870.4300, in compliance with GLP. The experiment was performed as a two-year oral feeding study in Sprague-Dawley CD rats. The read across substance was orally administered to rats (60/sex/group) at dose levels of 0, 300, 1000 or 2000 ppm (equivalent to mean intake levels of 0, 13, 44, and 88 mg/kg bw/day in males and 0, 17, 57 and 116 mg/kg bw/day in females) in the diet daily for 104 weeks. There were two control groups of 60/sex/group each. The animals were observed twice daily, body weights and clinical findings were recorded periodically. Clinical pathology measurements (haematology, clinical chemistry and urine analysis) were made at 6, 12, 18 and 24 months. At termination, a thorough post-mortem examination was conducted on all animals. Histopathology was conducted on a full set of tissues and organs from all animals in the control and high dose groups as well as on selected organs from animals in the low and mid-dose groups. Further, examinations were also performed to evaluate any treatment-related effect on tumour type or incidence in various organs. An increased incidence of loose faeces in male rats was observed which was considered to be potentially treatment-related, however, was not of biological significance. A reduction in mean absolute body weights and food consumption was observed in males and females in the high dose group. No treatment-related effects were observed in the type or incidence of clinical signs, survival, the type or incidence of palpable masses, clinical pathology, organ weights, gross and microscopic anatomic pathology or ophthalmology. Under the test conditions, there was no evidence of carcinogenic activity of the read across substance in rats administered at dietary dose levels up to 88 mg/kg bw/day or 71.3 mg a.i./kg bw/day in males and 116 mg/kg bw/day or 93.9 mg a.i./kg bw/day in females (Gill, 1991).

The biocides assessment reports available from RMS Italy on C12-16 ADBAC, overall concluded that C12-16 ADBAC, was not found to be carcinogenic under the conditions of the available studies. However, the corrected dietary doses were reported differently, where the NOAELs for neoplastic effects in rats were identified at 44 and 47 mg/kg/day for the US ISC (Gill, 1991) and EQC (Appelqvist, 2007) studies respectively (ECHA biocides assessment report, 2015). Nevertheless, considering that the systemic effects observed in these studies are regarded as secondary to the local irritation/corrosion caused by the test substance and as a result, no adverse systemic effects were identified and no systemic risk characterisation is required. Therefore, in line with the biocides assessment report, the NOAELs from the carcinogenicity studies with the read across substance have not been considered further for systemic risk assessment.