Registration Dossier

Toxicological information

Repeated dose toxicity: oral

Currently viewing:

Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Study period:
1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: limited reporting, EPA evaluated: Reliable without restriction; guideline study.

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EPA OPP 82-1 (90-Day Oral Toxicity)
Deviations:
no
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
Identity: Varisoft 475 (75%)
CAS RN: 68122-86-1;
Chemical name: Imidazolium compounds, 4,5-dihydro-1-methyl-2-nortallow alkyl-1-(2-tallow amidoethyl) Me sulfate)
Purity: 76.6% in isopropyl alcohol

Test animals

Species:
dog
Strain:
Beagle
Sex:
male/female
Details on test animals and environmental conditions:
Diet and water were available ad libitum
Weight of animals: Male animals weighed between 9.1 to 11.6 kg and females weighed 6.5 to 8.8 kg.

Administration / exposure

Route of administration:
oral: feed
Analytical verification of doses or concentrations:
not specified
Duration of treatment / exposure:
13 weeks
Exposure period: 91 to 93 days
Frequency of treatment:
Daily
Doses / concentrations
Remarks:
Doses / Concentrations:
4000, 12000 and 40000 ppm
Basis:
nominal in diet
No. of animals per sex per dose:
Four male and four female dogs
Control animals:
yes, plain diet
Details on study design:
No post-exposure recovery period

Examinations

Observations and examinations performed and frequency:
Observations were conducted at least twice daily for mortality and overt toxicity.
Detailed observations, body weights and food consumption were recorded weekly.
Ophthalmological examinations were performed on all animals prior to study initiation and at study termination.
Physical examinations, as well as hematological clinical chemistry and urological evaluations were conducted on all animals prior to study initiation and at monthly intervals during the study.
Sacrifice and pathology:
At study termination, a thorough post-mortem examination was conducted on all dogs. A complete set of all major tissues and organs was harvested and selected organs were weight. The saved tissues were processed histologically and microscopic examination was conducted.
Statistics:
Analysis of variance, Bartlett’s Test for Homogeneity of Variance, T-statistic as described by Steel and Torrie, Ostle and Dunnett’s Tables with a Bonferroni correctio

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
no effects observed
Haematological findings:
effects observed, treatment-related
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not specified
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
no effects observed
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:
Actual dose received: 142, 366 and 1322 mg/kg/day for males; 144, 632 and 1948 mg/kg/day for females
During the 13-week treatment period, one male and one female dog administered diets containing 40,000 ppm test substance lost 1.4 and 1.1 kg of body weight, respectively. The body weight gains of all other male and female dogs administered test substance in their diet were considered to be comparable to the body weight gains of the respective control animals in this study. During the first week of the study, there was a clear reduction in food consumption, indicating an aversion to the treated diets, in both the male and female dogs administered diets containing 40,000 ppm test substance. Thereafter, there continued to be evidence of aversion to the treated diets. In males, this was evidenced by a slight reduction in food consumption in all treatment groups. In females, the aversion was evidenced by an apparent increase in food spillage, which was considered to at least partially account for the difference in actual received dosages between males and females. All dogs survived to study termination. No changes noted in physical condition or appearance were considered to be related to treatment with the test substance. At termination, body weights appeared to be reduced for males and females receiving 40,000 ppm of the test substance in the diet. However, the reduction was due to the body weight loss of the one male and one female dog noted above. Small reductions in mean values for erythrocyte, hemoglobin and hematocrit were observed in both male and female dogs in the 40,000 ppm treatment group relative to the corresponding mean control values at one or more intervals of analysis. The differences were slight, a slight difference was also observed in the pre-study measurements, and the values were within historical control range. Therefore, the toxicological significance of the changes in hematology measurements was unclear. At all analysis intervals during the treatment period, mean cholesterol values for male and female dogs in the 40,000 ppm treatment group were reduced relative to the corresponding control group. The mean cholesterol values for the male dogs in the 12,000 ppm treatment group were also reduced relative to the corresponding controls. No treatment-related changes in urinalysis measurements were observed. No treatment related ophthalmologic changes or clinical observations, organ weight changes, or gross necropsy observations were seen at termination. A small number of macroscopic lesions were seen in both male and female animals across dietary concentrations. These lesions were considered to be spontaneous and not related to the administration of the test article. The ratio of the weight of the pituitary gland to the body weight of males at the 12,000 ppm dietary concentration was significantly decreased relative to the control group. The ratio of the weight of the pituitary gland to the body weight of females in the 4,000 ppm dietary concentration also was significantly decreased compared to the control group. The ratio of the weight of the right adrenal gland to the brain weight of the females was significantly increased at the 4,000 ppm dietary concentration compared to the control group. These findings were not consistent, could not be correlated with microscopic findings and were considered to be either spurious or due to biological variation, and not related to the administration of the test article. A small number of non-neoplastic findings were evident in this study. Many of them occurred in single animals. Some of the more common lesions included interstitial pneumonia, parathyroid cysts, pituitary cysts, thymic atrophy, c-cell hyperplasia of the thyroid gland and mineralization of the kidneys. Multifocal mineralization of the renal medulla of the kidneys was present in both male (16/16) and female (15/16) dogs of all dietary concentrations. The above lesions are considered to be common spontaneous findings in a 13-week beagle dog study, and none of the microscopic findings were considered to be related to the administration of the test article. Reproductive organs were examined meeting the requirements for SIDS/HPV reproductive screening.

Effect levels

Dose descriptor:
NOAEL
Effect level:
4 000 ppm
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: 4000 ppm: 144 mg a.i./kg/day for males and 144 mg a.i./kg/day for females

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
Dietary admixture to groups of 4 male and 4 female Beagle dogs up to 4% (40,000 ppm) into the diet for 91 days, resulted to questionable toxicity. The EPA concluded to NOAEL ~1635 mg/kg-bw/day (males and females).
Executive summary:

The study evaluated the subchronic oral toxicity of Varisoft 475 (75%) in a 13-week study in dogs. Four male and four female beagle dogs were offered the test substance in the diet at concentrations of 0, 4000, 12000 and 4000 ppm active ingredient for 13 weeks. Diet and water were available ad libitum, except prior to clinical pathology testing and necropsy, when diet and/or water were withheld overnight. Male animals weighed between 9.1 to 11.6 kg and females weighed 6.5 to 8.8 kg. Observations were conducted at least twice daily for mortality and overt toxicity. Detailed observations, body weights and food consumption were recorded weekly. Ophthalmological examinations were performed on all animals prior to study initiation and at study termination. Physical examinations, as well as hematological clinical chemistry and urological evaluations were conducted on all animals prior to study initiation and at monthly intervals during the study. At study termination, a thorough post-mortem examination was conducted on all dogs. A complete set of all major tissues and organs was harvested and selected organs were weight. The saved tissues were processed histologically and microscopic examination was conducted.

 

Actual dose received: 142, 366 and 1322 mg/kg/day for males; 144, 632 and 1948 mg/kg/day for females

During the 13-week treatment period, one male and one female dog administered diets containing 40,000 ppm test substance lost 1.4 and 1.1 kg of body weight, respectively. The body weight gains of all other male and female dogs administered test substance in their diet were considered to be comparable to the body weight gains of the respective control animals in this study. During the first week of the study, there was a clear reduction in food consumption, indicating an aversion to the treated diets, in both the male and female dogs administered diets containing 40,000 ppm test substance. Thereafter, there continued to be evidence of aversion to the treated diets. In males, this was evidenced by a slight reduction in food consumption in all treatment groups. In females, the aversion was evidenced by an apparent increase in food spillage, which was considered to at least partially account for the difference in actual received dosages between males and females. All dogs survived to study termination. No changes noted in physical condition or appearance were considered to be related to treatment with the test substance. At termination, body weights appeared to be reduced for males and females receiving 40,000 ppm of the test substance in the diet. However, the reduction was due to the body weight loss of the one male and one female dog noted above. Small reductions in mean values for erythrocyte, hemoglobin and hematocrit were observed in both male and female dogs in the 40,000 ppm treatment group relative to the corresponding mean control values at one or more intervals of analysis. The differences were slight, a slight difference was also observed in the pre-study measurements, and the values were within historical control range. Therefore, the toxicological significance of the changes in hematology measurements was unclear. At all analysis intervals during the treatment period, mean cholesterol values for male and female dogs in the 40,000 ppm treatment group were reduced relative to the corresponding control group. The mean cholesterol values for the male dogs in the 12,000 ppm treatment group were also reduced relative to the corresponding controls. No treatment-related changes in urinalysis measurements were observed. No treatment related ophthalmologic changes or clinical observations, organ weight changes, or gross necropsy observations were seen at termination. A small number of macroscopic lesions were seen in both male and female animals across dietary concentrations. These lesions were considered to be spontaneous and not related to the administration of the test article. The ratio of the weight of the pituitary gland to the body weight of males at the 12,000 ppm dietary concentration was significantly decreased relative to the control group. The ratio of the weight of the pituitary gland to the body weight of females in the 4,000 ppm dietary concentration also was significantly decreased compared to the control group. The ratio of the weight of the right adrenal gland to the brain weight of the females was significantly increased at the 4,000 ppm dietary concentration compared to the control group. These findings were not consistent, could not be correlated with microscopic findings and were considered to be either spurious or due to biological variation, and not related to the administration of the test article. A small number of non-neoplastic findings were evident in this study. Many of them occurred in single animals. Some of the more common lesions included interstitial pneumonia, parathyroid cysts, pituitary cysts, thymic atrophy, c-cell hyperplasia of the thyroid gland and mineralization of the kidneys. Multifocal mineralization of the renal medulla of the kidneys was present in both male (16/16) and female (15/16) dogs of all dietary concentrations. The above lesions are considered to be common spontaneous findings in a 13-week beagle dog study, and none of the microscopic findings were considered to be related to the administration of the test article. Reproductive organs were examined meeting the requirements for SIDS/HPV reproductive screening.

 

NOEL = 4,000 ppm (143 mg/kg/day)

LOAEL (LOEL) 12,000 ppm (366 and 632 mg/kg/day for males and females, respectively)

 

Evaluation by EPA concluded that:

Decreased food consumption observed in all treatment groups, most likely reflects decreased palatability in the treated diet. A significant decrease in body weight was observed in one male and one female at the highest dose. Study authors attributed observed decreases in mean cholesterol levels at or above 366 mg/kg-bw/day to decreased food intake. Macroscopic lesions (type not specified) were observed in all treatment groups; however, these lesions were not dose-related. Other findings reported in this study include significantly increased relative adrenal gland weight in females treated at 144 mg/kgbw/ day and significantly decreased relative pituitary gland weight in males and females at 1322 and 144 mg/kg-bw/day, respectively (level of significance not specified). These effects most likely reflect biological variation. No treatment- related histopathology was observed.

NOAEL ~ 1635 mg/kg-bw/day (males and females)