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Toxicological information

Repeated dose toxicity: dermal

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Administrative data

Endpoint:
short-term repeated dose toxicity: dermal
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 410 (Repeated Dose Dermal Toxicity: 21/28-Day Study)
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
1.2-ethane diole (ethylene glycol) with inhibitors > 92.5% ethylene glycol, < 1.42% na-p-tert-butyl-benzoate

Test animals

Species:
dog
Strain:
Beagle
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: in house
- Age at study initiation: 2 - 2.5 years
- Weight at study initiation: 16.4 kg
- Housing: singly in kennels
- Diet: pelleted diet (daily 500 g)
- Water: ad libitum
- Before blood and urine collection as well as before necropsy, a fasting period of 16 hours was warranted

ENVIRONMENTAL CONDITIONS
- Photoperiod (hrs dark / hrs light): same as the natural day/night rhythm.



Administration / exposure

Type of coverage:
other: clipped skin
Vehicle:
unchanged (no vehicle)
Details on exposure:
Before application period, the dogs were shaved on the back, flanks, front and waist. The test substance was applied daily undiluted onto the clipped skin. The application area was about 60% of the total body surface. The test substance was not washed off.
Analytical verification of doses or concentrations:
yes
Duration of treatment / exposure:
4 weeks
Frequency of treatment:
daily
Doses / concentrationsopen allclose all
Dose / conc.:
0.5 other: mL/kg bw (analytical per unit area)
Dose / conc.:
2 other: mL/kg bw (analytical per unit area)
Dose / conc.:
8 other: mL/kg bw (analytical per unit area)
No. of animals per sex per dose:
5
Control animals:
yes, concurrent no treatment
Details on study design:
In range-finding studies over a study period of 14 days (dermal application), no symptoms were seen given the test substance in concentrations of 1.5 mL for 14 days or 3.0 mL for 21 days. 12 mL of the test substance showed lethality after 6 and 14 days of exposure.
For the 4-week dermal study, 8 mL were used as highest concentration, 2 and 0.5 mL were used as lower concentrations.

Examinations

Observations and examinations performed and frequency:
- Check of dead animals twice a day.
- Clinical symptoms twice a day.
- Daily food consumption and body weight determination.
Sacrifice and pathology:
All animals were assessed by gross pathology and then a histopathological examination was carried out.
Statistics:
yes

Results and discussion

Results of examinations

Clinical signs:
effects observed, treatment-related
Description (incidence and severity):
At 8 mL test item/kg bw: The applied test substance caused apathy and/or somnolence in all male dogs. Individual animals showed further signs of toxicity, such as staggering gait, weakness of the extremities, vomiting, lateral position, diarrhea, etc.
Dermal irritation:
no effects observed
Mortality:
mortality observed, treatment-related
Description (incidence):
At 8 mL test item/kg bw: The applied test substance led to the premature death of 4 of the 5 male dogs used (3 of them sacrificed in a moribund state; one animal died)
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
At 8 mL test item/kg bw: loss of body weight was observed.
Food consumption and compound intake (if feeding study):
effects observed, treatment-related
Description (incidence and severity):
At 8 mL test item/kg bw: reduced feed consumption was observed.
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
effects observed, treatment-related
Description (incidence and severity):
At 8 mL test item/kg bw: There were numerous hematological findings, but these were less severe as the urinalysis effects
Clinical biochemistry findings:
effects observed, treatment-related
Description (incidence and severity):
At 8 mL test item/kg bw: There were numerous clinicochemical findings, but these were less server as the urinalysis effects
Urinalysis findings:
effects observed, treatment-related
Description (incidence and severity):
- At 8 mL test item/kg bw: All male dogs showed signs of renal insufficiency to a varying degree. Increased creatinine and urea levels in the plasma and changes in the urinalyses, such as an increased incidence of calcium oxalate crystals and renal and round epithelial cells, were the main findings. Polyuria and therefore reduced urine specific gravity were also observed.
- At 2 mL test item/kg bw: There were sporadically calcium oxalate crystals, initial signs of polyuria and an increased incidence of round and squamous epithelial cells in one male dog in each case.
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
- At 8 mL test item/kg bw: testicular atrophy was found in some cases. Uremic gastroenteritis was diagnosed in the dogs that died or were sacrificed prematurely.
- At 2 mL test item/kg bw:Testicular atrophy was observed in one animal.
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
- At 8 mL test item/kg bw: All male dogs had signs of oxalate nephrosis (intratubular oxalate crystals and liquefaction foci) and diffuse impairment of spermatogenesis
- At 2 mL test item/kg bw: moderate diffuse impairment of spermatogenesis was observed in one animal
Histopathological findings: neoplastic:
not examined
Other effects:
no effects observed

Effect levels

Dose descriptor:
NOAEL
Effect level:
2 220 mg/kg bw/day
Based on:
test mat.
Sex:
male
Basis for effect level:
other: see "Remarks"

Target system / organ toxicity

Critical effects observed:
yes
Lowest effective dose / conc.:
8 880 mg/kg bw/day
System:
urinary
Organ:
kidney
Treatment related:
yes
Dose response relationship:
yes
Relevant for humans:
yes

Applicant's summary and conclusion

Conclusions:
The oxalate nephrosis observed in the male dogs of the 8 mL/kg bw group with specific clinical, clinicochemical, hematological, urinalysis and gross-pathological and histopathological changes definitely correspond to the signs that are known from intoxication with pure monoethylene glycol. Further studies are required to establish whether the severe testicular damage that was found in all dogs at 8 mL/kg bw and in one dog at 2 mL/kg bw was caused by Na p-tert.-butyl benzoic acid (PTBBA), a typical testicular toxicant and a minor constituent of Glysantin G 105.
LD50 dermal (dog): > 2000 mg/kg bw