Butane-1,3-diol

Repeated dose toxicity: oral

Administrative data

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

31 August 1960 to 29 August 1962

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

insufficient number of animals per dose group, no analytical validation of test substance concentration in diet

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

chronic toxicity: oral

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

24 October 1960 to 1 November 1962

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

well performed study with some minor restrictions, pre-GLP

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Principles of method if other than guideline:

chronic feeding study in non-rodents

GLP compliance:

not specified

Remarks:

pre-GLP

Limit test:

no

Species:

dog

Strain:

Beagle

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Lu-Nor Farms, Kalamazoo, Michigan
- acclimation period: at least one month; during this period dogs received a vermifuge and were vaccinated against canine distemper, infectious canine hepatitis, and rabies.
- Age at study initiation: 6-16 month
- housing conditions: individually in metal cages
- Diet: ground Wayne dog food ad libitum; five days weekly the diet for each dog was supplemented with a 100 g ration of canned horsemeat
- Water: ad libitum

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

- the compound was added to both the dry dog food and the meat rations
- the compound was thoroughly incorporated into the ground dog food
- the basic diets were prepared weekly
- preparation of meat rations: appropriate amounts of the test compound were injected into the individual meat rations, which were then offered to the dogs. Dietary levels were computed on a moisture free basis.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

2 years

Frequency of treatment:

daily

Remarks:

Doses / Concentrations:
0, 0.5, 1.0, 3.0%
Basis:
nominal in diet

No. of animals per sex per dose:

4 animals per sex per dose

Control animals:

yes, plain diet

Details on study design:

Post-exposure period: none

Positive control:

no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: No

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

FOOD CONSUMPTION: Yes
- Time schedule for examinations: weekly
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: initially, at two and four weeks, at three, six, 12, 18 and 24 month
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: all dogs
- Parameters checked: erythrocyte count, total and differential leukocyte counts, hematocrit, hemoglobin, sedimentation rate determinations


CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: initialla, at two and four weeks, at three, six, 12, 18 and 24 month
- Animals fasted: No data
- How many animals: all dogs
- Parameters checked: bromsulphalein liver function tests, blood urea nitrogen determination


URINALYSIS: Yes
- Time schedule for collection of urine: initialla, at two and four weeks, at three, six, 12, 18 and 24 month
- Metabolism cages used for collection of urine: No data
- Animals fasted: No data
- Parameters checked: appearance, specific gravity, pH, sugar, acetone, ptrotein, bilirubin, occult blood, microscopic examination of the sediment

NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

After the study had completed one year, one female and one male from each group, including the controls, were sacrificed by exsanguination under thiamylal (Surital) sodium anesthesia, and complete autopsies were performed. The remaining animals were sacrificed after the study had completed two years.

GROSS PATHOLOGY: Yes

HISTOPATHOLOGY: Yes
- all tissues from the control and high level dogs sacrificed at one year plus bone marrow slides of the low and intermediate levels

SECTIONS PRESERVED in 10% formalin:
- all dogs: brain, pituitary, thyroid, lung, heart, mesenteric lymph node, stomach, small and large intestines, pancreas, spleen, liver, gallbladder, kidney, adrenal, urinary bladder, gonads, bone and bone marrow (rib junction)
-sections of the lower jaw bone were taken from selected animals of all dose groups at terminal sacrifice and stored in 10% formalin

Other examinations:

ORGAN WEIGHT: thyroid, heart, liver, spleen, kidneys, adrenals, gonads (males only)

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not specified

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

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:

In general, no treatment related effects were observed during this study. Effects seen in single animals were not regarded as treatment related, they are reported below.

One female of the 0.5% dose group (125 mg/kg bw/d) showed several periods of emesis. The effects were not connected with the dietary feeding of the test compound. The remaining animals showed normal behaviour during the first year.

One male dog of the 1% dose group (250 mg/kg bw/d) lost weight (up to 1.1 kg) during the study. At the end of the study the dog had nearly gained back its initial body weigth within 0.3 kg.

One female of the high dose group (3%; 750 mg/kg bw/d) was pregnant and delivered four healthy pups during the 10th week of the study. Fourteen weeks after birth an abdominal hernia was noted in this animal which was surgically repaired during the 25th week.

Hematological determinations, biochemical studies and urine analyses were within normal limits.

Some single cross pathological findings, which were not treatment related, were recorded:
- lowest dose (0.5%; 125 mg/kg bw/d): female dog: scar around teh anterior end of the right kidney
- mid dose (1.0%; 250 mg/kg bw/d): male dog: scar shaped cicatrix on the renal surface of one kidney; another male dog: thickening in the center of the spleen with a small necrotic area in the center; female dog: congested kidneys
- high dose (3.0%; 750 mg/kg bw/d): male dog: spleen with thickened margins and blue-black coloration, slightly congested kidneys; another male dog: mildly congested medulla in the kidney; female dog: lightly mottled liver

Organ weights were within the normal limits, a trend toward increased thyroid/body weigth ratios was not accompanied by histopathological findings.

The histopathological evaluation did not reveal any compound related effects.

Both, control and treated animals showed some focal chronic nephritis and tubular atrophy as well as mild to moderate glomerulitis.

Dose descriptor:

NOAEL

Effect level:

>= 750 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: calculated assuming a food factor of 0.025 (Gold et al., 1984)

Critical effects observed:

not specified

No adverse effects compared to control.

Calculation of dose in mg/kg bw/d is based on food consumption data of dogs as given in Gold et al (1984): A carcinogenic potency database of the standardized results of animal bioassays. Environmental Health Perspectives 58: 9 -319.

Conclusions:

No treatment related adverse effects were observed in a chronic feeding-study in dogs which received up to 3% 1,3-butylene glycole in food.

Executive summary:

1,3-butylene glycol was fed to adult male and female beagles at dietary level of 0, 0.5, 1.0, and 3.0% (0, 125, 250, and 750 mg/kg bw/d) for a period of two years (Celanese, 1963b; Scala and Paynter, 1967). The physical appearance, behavior, and total food consumption of the test dogs were comparable with those of the control dogs throughout the study. No definite signs of compound effect were observed in any of the test dogs. The results of the hematological, biochemical, and urine studies showed comparable values for the control and test groups. Organ weights and organ/body weight ratios of the test animals were generally within normal limits. Gross and microscopic evaluation of tissues from dogs sacrificed at one and two years of feeding revealed no consistent findings. The test dogs were considered to be within normal limits and comparable with the controls.

Cross-reference 2

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

31 August 1960 to 29 August 1962

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

significant methodological deficiencies

Remarks:

insufficient number of animals per dose group, no analytical validation of test substance concentration in diet

Reason / purpose for cross-reference:

reference to same study

Principles of method if other than guideline:

2-year feeding study in rodents

GLP compliance:

not specified

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 72 to 115 g (males); 68 to 109 g (females)
- Housing: individually in wire mesh cages
- Diet: ad libitum
- Water: ad libitum

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet: weekly
- Mixing appropriate amounts with: basal laboratory diet of Purina Laboratory Chow

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

2 years

Frequency of treatment:

daily

Post exposure period:

post exposure period: none

Remarks:

Doses / Concentrations:
0, 1.0, 3.0, 10.0%
Basis:
nominal in diet

No. of animals per sex per dose:

60 per sex in the control group; 30 per sex in the treatment groups

Control animals:

yes, plain diet

Positive control:

no

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly for the first 26 weeks, biweekly from week 27 through week 52, and every four weeks from week 53 through week 104


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes
- Time schedule for examinations: weekly for the first 26 weeks, biweekly from week 27 through week 52, and every four weeks from week 53 through week 104


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: after 4, 13, 26, 52, 78, and 104 weeks
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: five animals of each sex from each group
- Parameters checked: erythrocyte count, total and differential leukocyte counts, hemoglobin, hematocrit

CLINICAL CHEMISTRY: No

URINALYSIS: Yes
- Time schedule for collection of urine: fter 4, 13, 26, 52, 78, and 104 weeks
- Metabolism cages used for collection of urine: Yes (individual housing overnight in metabolism cages)
- How many animals: pooled samples from five rats of each sex in each group
- Animals fasted: No data
- Parameters checked: appearance, pH, specific gravity, sugar, acetone, protein, bilirubin, urobilinogen, occult blood, microscopic examination of the sediment


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

After 52 weeks, five males and five females from the control and each test group were sacrificed by exsanguination and autopsies performed. After 104 weeks all surviving test and control rats were sacrificed and autopsied.

HISTOPATHOLOGY:
Histopathological evaluation was performed on the preserved tissues (brain, pituitary, thyroid, lung, heart, liver, spleen, kidney, adrenal, pancreas, stomach, small and large intstines, urinary bladder, gonads, bone and bone marrow, mandibula) from each control and high level test rat (10% level) sacrificed. after 52 weeks and from five male and five female control and five male and four female high level test rate (10% level) sacrificed after 104 weeks. The tissue masses found in one female control rat and in one male rat of Group No. 4 (10% level) were also evaluated histopathologically.

Other examinations:

ORGAN WEIGHT: heart, liver, kidneys, spleen, testes; thyroids and adrenals were weighed after fixation in 10% formalin.

Statistics:

The parameters chosen for statistical evaluation at 52 weeks were growth, total food consumption, over-all food efficiency, survival, and hematological values. No attempt was made to analyze terminal body weights, organ weights, or organ/body weight ratios because of the wide variation in them.
The criteria evaluated statistically at 104 weeks were terminal body weights, organ weights, organ/body weight ratios, hematological values,and survival. No statistical evaluation was made of growth, food consumtion, and food efficiency.
Survival was analyzed by the life-table technique. All other criteria were examined by the analysis of variance or F-test at the 5% probability level. Body weights were prepared for analysis by the method of Rao. Before completing each F-test, Bartlett's test was applied to assure homogeneity of the variances. If the variances were homogeneous the F-test was completed in the normal Fashion. Whenever a significant F-value was obtained those groups significantly different from the controls were determined by Scheffe's test. Whenever heterogeneous variances were obtained, comparisons were made by the Fisher-Behrens modified "t"-technique. A more detailed description of these methods may be found in publications by Ostle, B., Statistics in Research, Ames, Iowa, Iowa State College Press, 1956; Snedecor, G. W., Statistical Methode, Ames, Iowa, Iowa State College Press, 1956; Rao, C. R., Biometrics 14, 1, 1958; and Sachs, R., Toxicol. Appl. Pharmacol. 1, 203, 1959.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

not specified

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

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:

CLINICAL SIGNS AND MORTALITY
Signs of respiratory involvement (wheezing, rapid or labored respiration, nasal dischare, and inflamed eyes) were noted with equal frequency among the rats in the control and various test groups. These signs were slight during the first six month of the study and became more frequent and severe as teh study proceeded. Mass treatments with antibiotics were institued, however, were of only transient value. Mortality because of respiratory disease, in the control and test animals alike, increased during the latter part of the first year and remained high throughout the second year of the study.

Subcutaneous tissue masses of varying size and location were observed predominantly in the female animals and especially in the controls. The incidence of such tissue masses is described below. Frequent locations of the tissue masses were the axillary and the inguinal areas. In two rats large tissue masses adhered to the body sides. Three animals exhibited nodules in the perianal region. One rat had a wart-like growth at one ear, and three other rats displayed one tissue node each at the throat, lip and vagina. Several rats showed two tissue masses at different locations. The
majority of the subcutaneous tissue growths were of firm consistency, loosely attached to the underlying tissue, and therefore easily movable.
Others were softer, of fatty consistency. The growths varied in size, the smaller ones being pea sized and the larger ones reaching the size and shape of an Idaho potato. In many instances the skin cover was intact. In some rats, however, the growths were ulcerated, partly necrotic, and exuded a foul odor. The earliest incidence of a subcutaneous growth was observed in a female control rat, where a firm tissue mass at the right hip was noted beginning with the 19th week; the mass became ulcerated and the animal died in the 37th week. During the latter part of the first year (40 weeks) tissue masses became apparent in three more rats. The other tissue masses developed during the second year of the study.


BODY WEIGHT AND WEIGHT GAIN
No substance related effects, for details see chapter 7.5.1.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
No substance related effects, for details see chapter 7.5.1.

FOOD EFFICIENCY
No substance related effects, for details see chapter 7.5.1.


OPHTHALMOSCOPIC EXAMINATION
no data

HAEMATOLOGY
All in chapter 7.5.1 mentioned abnormal findings (e.g. somewhat elevated segmented neutrophils, low hematocrit, hemoglobin and erythrocyte values, elevated leukocyte counts, polychromia in all groups ) probably were due to the high incidence of pulmonary disease among the rats and in some instances also to the presence of tissue masses.


URINALYSIS
no adverse effects


ORGAN WEIGHTS
Organ weights and weight ratios showed a wide variation within normal limits. Statistical analysis revealed no significant differnece between the control data and the high level test data.

GROSS PATHOLOGY
Findings at autopsy in the rats which were sacrificed at 52 and 104 weeks or which died or were sacrificed in moribund condition during the course of the study did not reveal any consistent gross changes in the tissues or viscera of the test rats that could be associated with the ingestion of the test material. Infected lungs (consolidation, abscesses, emphysema and in some cases, adhesions to the thoracic wall or areas of firm white tissue) were found in the majority of the control and test rats sacrificed after 52 and 104 weeks and in all animals which died or were sacrificed in moribund condition during the course of the study.

The subcutaneous tissue masses observed in a number of female and a few male control and test rats in the course of the study varied in weight from one gram to 291 grams. In most cases these growths were encapsulated, nodular, of firm consistency; the cut surface was nodular or homogeneous, gray dull or glistening white, sometimes showing hemorrhagic pockets of caseous, necrotic masses. A few tissue masses were of softer consistency and of predominantIy homogeneous structure, some of them showing a dark black cut surface. Internal tissue masses, concealed in the body cavities, were detected at autopsy in four male and eight female control and test rats, and are described below. Two of these animals also showed subcutaneous tissue masses.

HISTOPATHOLOGY: NON-NEOPLASTIC
The microscopic examination did not reveal any consistent alterations in the cellular or tissue structure of the test animals that could be associated with the ingestion of the test material. The only lesions consistently present in both the control and test animals were due to chronic inflammatory disease and neoplasia.

HISTOPATHOLOGY: NEOPLASTIC
Several of the subcutaneous tissue masses encountered, primarily in female control and test rate were identified as mammary fibromas,
fibroadenomas, and carcinomas. The abdominal tumor in a male high level rat (10% level), described as replacing the left kidney and the left adrenal, was identified as a cortical carcinoma. The wart-like nodule observed at the ear of a female control was diagnosed as a melanoma.

Relevance of carcinogenic effects / potential:

The study was judged to be relevant for the evaluation of carcinogenicity of 1,3-butylene glycol after chronic oral application. There was no treatment related increase in tumor incidence or any other adverse effect as compared to control up to the highest dose tested which is well above the recommended limit dose.

Dose descriptor:

NOAEL

Effect level:

5 000 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: calculated (10% in diet, food factor 0.05; see: Guidance on Information requirements R.8)

Remarks on result:

other: Effect type: carcinogenicity (migrated information)

Dose descriptor:

NOAEL

Effect level:

5 000 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: calculated (10% in diet, food factor 0.05; see: Guidance on Information requirements R.8)

Remarks on result:

other: Effect type: toxicity (migrated information)

There was no treatment related increase in carcinogenic and non-carcinogenic effects in treated animals compared to the control.

The incidence of subcutaneous tissue masses was as follows:

Dietary level (%)	male	female
0	1	15
1	1	0
3	0	6
10	1	3

The internal tissue masses, concealed in the body cavities, and detected at autopsy in four male and eight female rats are described in the following:

dietary level (%)	sex	gross autopsy findings
0	M	Red tissue mass attached to left lung lobe.
0	F	Abdominal, cherry-sized, dark red nodule attached to the uterus at the bifurcation.
0	F	Tissue masses involving both ovaries.
1	F	Nodular, firm, gray-white tissue mass containing hemorrhagic pockets, closely attached to and partly penetrating spleen.
1	F	Several large hemorrhagic nodules attached to pancreas and spieen, and a large, irregularly nodular mass involving cecum and upper colon.
3	F	Diffuse nodular tissue mass involving ileum and cecum and spreading through the lower abdominal cavity.
3	F	Firm, congested node at right uterine horn.
10	M	Large, abdominal tissue mass, encapsulated, soft, with hemorrhagic pockets, involving left kidney and left adrenal; the cut surface of the growth revealed the indistinct outline of a pale, greatly enlarged kidney; the left adrenal could not be located.
10	M	Firm, irregularly shaped tissue mass involving the thymus.
10	M	Cherry-sized, dark brown, firmly elastic nodule between the liver lobes.
10	F	Encapsulated, greatly hemorrhagic, friable tissue mass enclosing the left ovary.
10	F	Large tissue mass adhering to the left lung lobe.

Conclusions:

No treatment related adverse effects (carcinogenic and non-carcinogenic) were observed in a chronic feeding-study in rats which received up to 10% (5000 mg/kg bw/d) 1,3-butylene glycol in the diet.

Executive summary:

Albino rats received 1,3 -butylene glycol in the diet at levels of 1.0, 3.0, and 10.0% (500, 1500, and 5000 mg/kg bw/d) for two years. The control group was fed the basal laboratory diet (Celanese, 1963a, Scala and Paynter, 1967). The physical appearance and behaviour of the rats generally was comparable with those of the corresponding controls. Signs of respiratory involvement were observed with equal frequency among the control and various test groups. No compound related adverse effects were observed. Subcutaneous and internal neoplasms were encountered in a number of control and test animals, primarily in females. Some of the neoplasms found at autopsy were identified as fibromas, fibrosarcomas, carcinomas, or adenomas and melanomas.

Cross-reference 3

Reason / purpose for cross-reference:

reference to same study

Reference

Endpoint:

carcinogenicity: oral

Type of information:

experimental study

Adequacy of study:

other information

Study period:

24 October 1960 to 1 November 1962

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: insufficient number of test animals per sex and dose group, exposure period does not cover the majority of the life span

Reason / purpose for cross-reference:

reference to same study

Principles of method if other than guideline:

chronic feeding study in non-rodents

GLP compliance:

not specified

Species:

dog

Strain:

Beagle

Sex:

male/female

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

2 years

Frequency of treatment:

daily

Post exposure period:

none

Remarks:

Doses / Concentrations:
0, 0.5, 1.0, 3.0%
Basis:
nominal in diet

No. of animals per sex per dose:

4 animals per sex per dose

Control animals:

yes, plain diet

Positive control:

no

Relevance of carcinogenic effects / potential:

The study was judged not to be relevant for the evaluation of carcinogenicity of 1,3-butylene glycol, because a) the number of animals per sex and dose group was to low, b) the dose range did not cover the range of toxic effects, and c) exposure was not during the majority of the life span. But the findings of this study support the results obtained in rats.

Dose descriptor:

NOAEL

Effect level:

750 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: calculated (3% in diet, food factor 0.025; see Gold et al., 1984)

Remarks on result:

other: Effect type: carcinogenicity (migrated information)

Dose descriptor:

NOAEL

Effect level:

750 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: calculated (3% in diet, food factor 0.025; see Gold et al., 1984)

Remarks on result:

other: Effect type: toxicity (migrated information)

There was no treatment related increase in carcinogenic and non-carcinogenic effects in treated animals compared to the control.

Calculation of dose in mg/kg bw/d is based on the data of Gold et al. (1984): A carcinogenic potency database of the standardized results of animal bioassays. Environmental Health Perspectives 58: 9 -319.

Conclusions:

No treatment related carcinogenic and non carcinogenic effects were observed in a chronic feeding-study in dogs which received up to 3% 1,3-butylene glycol in food (750 mg/kg bw/d).

Executive summary:

1,3-butylene glycol was fed to adult male and female beagles at dietary level of 0, 0.5, 1.0, and 3.0% for a period of two years (0, 125, 250, 750 mg/kg bw/d). No signs of compound related effects were observed in any of the dogs. The physical appearance, behavior, and total food consumption of the test dogs were comparable with those of the control dogs throughout the study. The results of the hematological, biochemical, and urine studies showed comparable values for the control and test groups. Organ weights and organ/body weight ratios of the test animals were generally within normal limits. Gross and microscopic evaluation of tissues from dogs sacrificed at one and two years of feeding revealed no consistent findings. The test dogs were considered to be within normal limits and comparable with the controls (Celanese, 1963b; Scala and Paynter, 1967).

Data source

Reference

Reference 1

Reference Type:

publication

Title:

Unnamed

Year:

1967

Report date:

1967

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

1963

Report date:

1963

Reference 3

Reference Type:

study report

Title:

Unnamed

Year:

1961

Report date:

1961

Materials and methods

Principles of method if other than guideline:

chronic feeding study in rodents

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Butane-1,3-diol

EC Number:

203-529-7

EC Name:

Butane-1,3-diol

Cas Number:

107-88-0

Molecular formula:

C4H10O2

IUPAC Name:

butane-1,3-diol

Test material form:

liquid

Details on test material:

- Name of test material (as cited in study report): 1,3-butylene glycol
-purity: "considered to be free of impurities"
- clear, viscous, colorless liquid with a varnish-like odor

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 72 to 115 g (males); 68 to 109 g (females)
- Housing: individually in wire mesh cages
- Diet: ad libitum
- Water: ad libitum

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

DIET PREPARATION
- Rate of preparation of diet: weekly
- Mixing appropriate amounts with basal laboratory diet of Purina Laboratory Chow

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

2 years

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 1.0, 3.0, 10.0%
Basis:
nominal in diet

No. of animals per sex per dose:

60 per sex in the control group; 30 per sex in the treatment groups

Control animals:

yes, plain diet

Details on study design:

Post-exposure period: none

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly for the first 26 weeks, biweekly from week 27 through week 52, and every four weeks from week 53 through week 104


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study):
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes
- Time schedule for examinations: weekly for the first 26 weeks, biweekly from week 27 through week 52, and every four weeks from week 53 through week 104


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No

OPHTHALMOSCOPIC EXAMINATION: No

HAEMATOLOGY: Yes
- Time schedule for collection of blood: after 4, 13, 26, 52, 78, and 104 weeks
- Anaesthetic used for blood collection: No data
- Animals fasted: No data
- How many animals: five animals of each sex from each group
- Parameters checked: erythrocyte count, total and differential leukocyte counts, hemoglobin, hematocrit

CLINICAL CHEMISTRY: No

URINALYSIS: Yes
- Time schedule for collection of urine: fter 4, 13, 26, 52, 78, and 104 weeks
- Metabolism cages used for collection of urine: Yes (individual housing overnight in metabolism cages)
- How many animals: pooled samples from five rats of each sex in each group
- Animals fasted: No data
- Parameters checked: appearance, pH, specific gravity, sugar, acetone, protein, bilirubin, urobilinogen, occult blood, microscopic examination of the sediment


NEUROBEHAVIOURAL EXAMINATION: No

Sacrifice and pathology:

After 52 weeks, five males and five females from the control and each test group were sacrificed by exsanguination and autopsies performed. After 104 weeks all surviving test and control rats were sacrificed and autopsied.

Organs preserved from sacrificed animals in 10% formalin:
brain, pituitary, thyroid, lung, heart, liver, spleen, kidney, adrenal, pancreas, stomach, small and large intestines, urinary bladder, gonads, bone and bone marrow, unusual lesions found at autopsy, mandibula

HISTOPATHOLOGY:
Histopathological evaluation was performed on the preserved tissues (brain, pituitary, thyroid, lung, heart, liver, spleen, kidney, adrenal, pancreas, stomach, small and large intstines, urinary bladder, gonads, bone and bone marrow, mandibula) from each control and high level test rat (10% level) sacrificed. after 52 weeks and from five male and five female control and five male and four female high level test rate (10% level) sacrificed after 104 weeks. The tissue masses found in one female control rat and in one male rat of Group No. 4 (10% level) were also evaluated histopathologically.

Other examinations:

ORGAN WEIGHT: heart, liver, kidneys, spleen, testes; thyroids and adrenals were weighed after fixation in 10% formalin

Statistics:

The parameters chosen for statistical evaluation at 52 weeks were growth, total food consumption, over-all food efficiency, survival, and hematological values. No attempt was made to analyze terminal body weights, organ weights, or organ/body weight ratios because of the wide variation in them.
The criteria evaluated statistically at 104 weeks were terminal body weights, organ weights, organ/body weight ratios, hematological values,and survival. No statistical evaluation was made of growth, food consumtion, and food efficiency.
Survival was analyzed by the life-table technique. All other criteria were examined by the analysis of variance or F-test at the 5% probability level. Body weights were prepared for analysis by the method of Rao. Before completing each F-test, Bartlett's test was applied to assure homogeneity of the variances. If the variances were homogeneous the F-test was completed in the normal Fashion. Whenever a significant F-value was obtained those groups significantly different from the controls were determined by Scheffe's test. Whenever heterogeneous variances were obtained, comparisons were made by the Fisher-Behrens modified "t"-technique. A more detailed description of these methods may be found in publications by Ostle, B., Statistics in Research, Ames, Iowa, Iowa State College Press, 1956; Snedecor, G. W., Statistical Methode, Ames, Iowa, Iowa State College Press, 1956; Rao, C. R., Biometrics 14, 1, 1958; and Sachs, R., Toxicol. Appl. Pharmacol. 1, 203, 1959.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not specified

Ophthalmological findings:

not specified

Haematological findings:

no effects observed

Clinical biochemistry findings:

not specified

Urinalysis findings:

no effects observed

Behaviour (functional findings):

not specified

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:

Chronic application of 0, 1.0, 3.0 or 10.0% 1,3-butylene glycol in the diet (0, 500, 1500 or 5000 mg/kg/d ) did not induce adverse effects in rats.

CLINICAL SIGNS AND MORTALITY
Rats of the control and various test groups showed signs of respiratory involvement (wheezing, rapid or labored respiration, nasal dischare, and inflamed eyes) with equal frequency. These signs were slight during the first six month of the study and became more frequent and severe as the study proceeded. Mass treatments with antibiotics were institued, however, were of only transient value. There were no differences between control and test animals with respect to mortality due to respiratory disease. Incidence increased during the latter part of the first year and remained high throughout the second year of the study. Incidence of subcutaneous tissue masses is described in chapter 7.7

BODY WEIGHT AND WEIGHT GAIN
During the first year of the study, growth rate for the males and females in dose group No. 2 (1.0% level, 500 mg/kg/d) and dose group No. 3 (3.0% level, 1500 mg/kg/d) was not significantly different from that of the corresponding control groups. In Group No. 4 (10% level, 5000 mg/kg/d), the growth rate was significantly higher than that for the male controls. While this trend was also present in the females of Group No. 4, the higher growth rate was not significant.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study)
Food consumption for the males in Group No. 4 for the first 13 weeks and from the 28th through the 52nd week was significantly
lower than that for the male controls. Food consumption was comparable among the other test groups and the respective controls.

FOOD EFFICIENCY
Food efficiency was significantly higher in Group No. 4 during the first 13 weeks (males and females) and from the 27th through the 52nd week (females).


OPHTHALMOSCOPIC EXAMINATION
no data

HAEMATOLOGY
During the first year of the study all hematological values remained generally within normal limits and were comparable among the control and test groups. At 52 weeks the percentages for the segmented neutrophils were somewhat elevated for the rats in all groups including the controls. At 78 and 104 weeks the segmented neutrophil percentages were even more elevated and in some cases exceeded the lymphocyte percentages. Furthermore, at the 545-day interval and even more so at termination, low hematocrit, hemoglobin, and erythrocyte values and/or elevated leukocyte counts
were obtained for a number of rats in all groups including the controls. An additional finding at termination was moderate or marked polychromia or hypochromia in several rats of all groups. One male rat in Group No. 2 (1.0% level, 1000 mg/kg/d) exhibited one nucleated erythrocyte per 100 White blood cells. All above mentioned abnormal findings probably were due to the high incidence of pulmonary disease among the rats and in some instances also to the presence of tissue masses.


URINALYSIS
The results of the urine analyses were comparable among the control and test groups throughout the study. No particular significance can be attached to the increased protein content in the urine of the male and female test rats at termination because of the poor health of the rats and the small number of survivors in some of the groups.


ORGAN WEIGHTS
Organ weights and weight ratios showed a wide variation within normal limits. Statistical analysis revealed no significant differnece between the control data and the high level test data.

GROSS PATHOLOGY
Findings at autopsy in the rats which were sacrificed at 52 and 104 weeks or which died or were sacrificed in moribund condition during the course of the study did not reveal any consistent gross changes in the tissues or viscera of the test rats that could be associated with the ingestion of the test material. Infected lungs (consolidation, abscesses, emphysema and in some cases, adhesions to the thoracic wall or areas of firm white tissue) were found in the majority of the control and test rats sacrificed after 52 and 104 weeks and in all animals which died or were sacrificed in moribund condition during the course of the study. Subcutaneous tissue masses, primarily in female control and test rats, were observed. For details see chapter 7.7.

HISTOPATHOLOGY: NON-NEOPLASTIC
Microscopic examination of tissue sections from the high level test rats (10% level, 5000 mg/kg/d) sacrificed after 52 weeks did not reveal any consistent alterations. The cellular structure of the sections from the test rats was generally similar to that observed in the sections from the controls. Slight to moderate vacuolation of liver cells, present in some of the high level rats at 104 weeks, was considered to be of no significance. The only lesions consistently present in both the control and test animals were due to chronic inflammatory disease and neoplasia.

HISTOPATHOLOGY: NEOPLASTIC
Several subcutaneous tissue masses were identified as mammary fibromas, fibroadenomas, and carcinomas, or adenomas and melanomas. For details see chapter 7.7.

Effect levels

Dose descriptor:

NOAEL

Effect level:

5 000 mg/kg bw/day (nominal)

Sex:

male/female

Basis for effect level:

other: calculated (10% in diet, food factor 0.05; see: Guidance on Information requirements R.8)

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

No adverse effects compared to control

Applicant's summary and conclusion

Conclusions:

No treatment related adverse effects were observed in a chronic feeding-study in rats which received up to 10% (5000 mg/kg/d) 1,3-butylene glycol in food.

Executive summary:

Rats received 1,3-butylene glycol in the diet at levels of 1.0, 3.0, and 10%, for two years (500, 1500 and 5000 mg/kg/d) (Celanese, 1963a, Celanese, 1961, Scala and Paynter, 1967). The control group was fed the basal laboratory diet. The physical appearance and behavior of the test rats generally was comparable with those of the corresponding controls. Signs of respiratory involvement were observed with equal frequency among the control and various test groups. None of the test rats showed any sign of compound effect.

Mortality in the various groups increased markedly during the second half of the first year and remained high during the second year of the study due to respiratory diseases. Hematological values and the results of urine analyses for treated rats were generally within normal limits and comparable with those of the controls. Minor abnormalities in hematological parameters, encountered in control and test animals alike during the second year, were compatible with inflammatory disease and neoplasia.

Organ weights and ratios were within normal limits and comparable with the controls. Subcutaneous and internal neoplasms were encountered in a number of control and test animals, primarily in females. Microscopic examination of tissue sections did not reveal any consistent alterations.