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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1961-1963
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: This study was conducted prior to GLP and test guidelines, but sufficient data is available for interpretation of results.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1963
Report Date:
1963

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Beagle dogs were divided into matched groups and started on diets containing 0.0 (control), 1.0, 0.5, 0.25, or 0.125% Benax 2A1. Four males and four females comprised each group, except for the 1.0% level, which consisted of two males and four females. The percentage levels given above were approximately equivalent to the administration of 0, 319, 128, 65, and 34 mg/kg/day Benax 2A1, respectively, over the two-year period.

General appearance and behavior, growth, food consumption, hematological values, determinations of serum urea nitrogen content, alkaline phosphatase and transaminase activity and bromsulfophthalein dye retention, final organ and body weights, and gross and microscopic examination of the tissues were conducted.
GLP compliance:
no
Remarks:
pre-GLP
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
CRI Name: Benzenesulfonic acid: X-(X-Dodecyl) -X-Phenoxy-; sodium salt
Trade name: Benax 2A1
Appearance: Light-colored powder
Purity: 90.03%
Composition: 90.03% active, 3.16% water, 5.19% NaCl, 1.62% Na2SO4, and 1.20 ppm Iron
pH- 10.10 (10% in water)
Source: F. C. Tuttle, Benzene Products Laboratory
Reference: Lot 180, Drum #2
M.W.: 440.6

Test animals

Species:
dog
Strain:
Beagle
Sex:
male/female
Details on test animals and environmental conditions:
Male and female beagle hounds of approximately three months of age were obtained from a commercial kennel and housed at the Biochemical Research Laboratory. The pups remained in the laboratory three months prior to the beginning of the experiment, during which time they were vaccinated for distemper, hepatitis, and leptospira. The stock diet for the first two months was Famo Labomtory Chow; it was then changed to Purina Laboratory Chow for the remaining time. Dogs of each sex per level were housed together and had free access to food and water at all times.

On October 17, 1961, the dogs were divided into matched groups.

Administration / exposure

Route of administration:
oral: feed
Vehicle:
unchanged (no vehicle)
Details on oral exposure:
Dogs were divided into matched groups and given diets containing 0.0 (control), 1.0, 0.5, 0.25, or 0.125% Benax 2A1. Four males and four females comprised each group, except for the 1.0% level, which consisted of two males and four females. The percentage levels given above were approximately equivalent to the administration of 0, 319, 128, 65, and 34 mg/kg/day Benax 281, respectively, over the two-year period.
Analytical verification of doses or concentrations:
no
Details on analytical verification of doses or concentrations:
No data
Duration of treatment / exposure:
2 years
Frequency of treatment:
Daily
Doses / concentrationsopen allclose all
Remarks:
Doses / Concentrations:
0.0 (control), 1.0, 0.5, 0.25, or 0.125% Benax 2A1
Basis:
nominal in diet
Remarks:
Doses / Concentrations:
0, 319, 128, 65, and 34 mg/kg/day Benax 2A1
Basis:
nominal in diet
No. of animals per sex per dose:
Four males and four females comprised each group, except for the 1.0% level, which consisted of two males and four females.
Control animals:
yes, plain diet
Details on study design:
Beagle dogs were divided into matched groups and started on diets containing 0.0 (control), 1.0, 0.5, 0.25, or 0.125% Benax 2A1. Four males and four females comprised each group, except for the 1.0% level, which consisted of two males and four females. The percentage levels given above were approximately equivalent to the administration of 0, 319, 128, 65, and 34 mg/kg/day Benax 281, respectively, over the two-year period.

Each dog was weighed weekly for the first three months of the experiment and twice a week thereafter. Food consumption was recorded 3 during the first , 12th, and 16th months, and one week out of each month from 18 months to the end of the experiment. Hematological studies and determinations of serum urea nitrogen content and alkaline phosphatase activity were made before the beginning of the experiment and at three, six, nine, 12, 18, and 24 months. Transaminase activity (SGPT) was determined at one and two years and bromsulfophthalein dye retention at one year. Urea nitrogen content and transaminase and alkaline phosphatase activity was determined. Pre-exposure liver biopsies were performed on one dog of each sex per level, as well as at six, 12, and 18 months on the experiment.

At the end of the two-year period the animals were fasted overnight and weighed before examination at autopsy. The lungs, heart, liver, kidney, spleen, testes, and brain were removed and weighed. Portions of each organ,as well as spinal cord, peripheral nerve, pituitary, thyroid, adrenal, aorta, lymph node, thymus, esophagus, stomach, small and large intestine, pancreas, urinary bladder, ovary, uterus, and skeletal muscle were preserved. The tissues were then sent to the International Research and Development Corporation in Mattawan, Michigan, for preparation of hematoxylin-eosin stained sections and microscopic examination.
Positive control:
Non

Examinations

Observations and examinations performed and frequency:
Each dog was weighed weekly for the first three months of the experiment and twice a week thereafter. Food consumption was recorded 3 during the first , 12th, and 16th months, and one week out of each month from 18 months to the end of the experiment.
Sacrifice and pathology:
Hematological studies and determinations of serum urea nitrogen content and alkaline phosphatase activity were made before the beginning of the experiment and at three, six, nine, 12, 18, and 24 months. Transaminase activity (SGPT) was determined at one and two years and bromsulfophthalein dye retention at one year. Urea nitrogen content and transaminase and alkaline phosphatase activity was determined. Pre-exposure liver biopsies were performed on one dog of each sex per level, as well as at six, 12, and 18 months on the experiment.

At the end of the two-year period the animals were fasted overnight and weighed before examination at autopsy. The lungs, heart, liver, kidney, spleen, testes, and brain were removed and weighed. Portions of each organ,as well as spinal cord, peripheral nerve, pituitary, thyroid, adrenal, aorta, lymph node, thymus, esophagus, stomach, small and large intestine, pancreas, urinary bladder, ovary, uterus, and skeletal muscle were preserved. The tissues were then sent to the International Research and Development Corporation in Mattawan, Michigan, for preparation of hematoxylin-eosin stained sections and microscopic examination.
Other examinations:
None
Statistics:
No data

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Mortality:
mortality observed, treatment-related
Body weight and weight changes:
effects observed, treatment-related
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
effects observed, treatment-related
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
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
Details on results:
Benax 2A1 was fed in the diets of male and female beagle hounds for a period of two years at the concentrations of 1.0, 0.5, 0.25, or 0.125%. Food consumption data indicated that the dietary concentrations given above administered the test substance in amounts of 319, 128, 65 and 34 mg/kg/day respectively. No evidence of adverse effect whatsoever was observed in the dogs given the 0.5% dietary level or below as judged by general appearance and behavior, growth, food consumption, hematological values, determinations of serum urea nitrogen content, alkaline phosphstase and transaminase activity, and bromsulfophthalein dye retention, final body and organ weights, and gross and microscopic examination of the tissue.

The two males and four females which received 1.0% Benax 2A1 in their diets showed growth retardation. Because male dog #330 and female dog #343 lost approximately one-third of their original weights, they were sacrificed after 14 months of the experiment. The final weight of the other male was essentially the same as his original weight, while two of the remaining females lost weight and the third gained. The 1.0% level was not readily acceptable to the dogs. Persistent scratching at the feeders was noted during the early months of the experimental period. This was noted to some extent also in the group of dogs receiving the 0.5% level. Food consumption records for the first month reflect this observation in that the unusually high figures in comparison with the controls was due to spillage and wastage. Therefore, it is possible that the growth retardation in the dogs maintained on the diet containing 1.0% Benax 2A1 may be related somewhat to decreased food intake, at least during the early part of the experiment. Intestinal irritation, as evidenced by loose stools and diarrhea which these dogs exhibited for the first 45 days on the experiment, also may have contributed to their failure to gain weight.

Alkaline phosphatase determinations at various intervals throughout the two-year period showed a slight increase in activity in both of the male dogs and in two of the four females on the 1.0% level. However, the determination of two other liver function tests, that of bromsulfophthalein dye retention at approximately one year and transaminase activity at one and two years, gave normal results in comparison with the control values.

An increased liver/body weight ratio was found in the male dog which was sacrificed after 14 months. The organ/body weight ratio of the kidney of the 1.0% male which was carried through to the end of the two-year period was also increased. However, these variations are due to decreased body weights, since there was no increase in the organ weights when considered on the absolute basis in grams.

Hematological values, serum urea nitrogen determinations, and gross and microscopic examination of the tissues gave no indication of any adverse effects in the dogs which received 1.0% Benax 2A1 in their diets when compared with the controls.

Effect levels

Dose descriptor:
NOAEL
Effect level:
128 mg/kg bw/day (nominal)
Sex:
male/female
Basis for effect level:
other: Based on growth retardation, loose stools and diarrhea, and increased alkaline phosphatase observed in dogs given 319 mg/kg/day or 1.0% in diet. Note: 128 mg/kg/day= 0.5% on diet.

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

None

Applicant's summary and conclusion

Conclusions:
The systemic NOEL in Beagle dogs was determined to be 0.5% or 128 mg DOWFAX 2A1/kg bw/day.
Executive summary:

Male and female beagle hounds were maintained for two years on diets containing 0.5, 0.25, or 0.125% Benax/DOWFAX 2A1 (equivalent to 128, 65, and 34 mg/kg/day) without evidence of adverse effect as judged by general appearance and behavior, growth, food consumption, hematological values, determinations of serum urea nitrogen content, alkaline phosphatase and transaminase activity and bromsulfophthalein dye retention, final organ and body weights, and gross and microscopic examination of the tissues compared to control animals. At the highest dose level (1% or 319 mg/kg/day, study LOAEL), growth was retarded in the male and female dogs fed Benax/DOWFAX 2A1. These dogs also had loose stools and diarrhea for the first 45 days of the experiment; slightly increased alkaline phosphatase activity in both male dogs and in two out of four female dogs; variations in a few organ/body weight ratios with no difference in organ weights when considered on the absolute basis in grams. Hematological determinations, serum urea nitrogen and transaminase values, determination of bromsulfophthalein dye retention, and gross and microscopic examination of the tissues gave no indication of adverse effects when compared with the controls. Based on these effects, the systemic NOEL in Beagle dogs was determined to be 0.5% or 128 mg DOWFAX 2A1/kg bw/day.