Registration Dossier

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Study well documented, meets generally accepted scientific principles, acceptable for assessment. Restriction: Only male animals used

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Range-finding toxicity data: list IV
Author:
Smyth HF Jr, Carpenter CP and Weil CS
Year:
1951
Bibliographic source:
Arch. Ind. Hyg. Occup. Med. 4, 119-122
Reference Type:
study report
Title:
Unnamed
Year:
1949
Report Date:
1949

Materials and methods

Principles of method if other than guideline:
Method: other: Smyth HF Jr, Carpenter CP (1944): The place of the range finding test in the industrial toxicology laboratory. J. Ind. Hyg. Toxicol. 26, 269-273 and subsequent updates
GLP compliance:
no
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
tetrahydronaphthalene procured from Eastman Kodak Co. under their number P550 on 10 Jan. 1949. No data on purity

Test animals

Species:
rat
Strain:
Sherman
Sex:
male
Details on test animals and environmental conditions:
TEST ORGANISMS: 
- Weight at study initiation: 90-120 g
- Feeding: No previous withdrawal of food

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
ADMINISTRATION: 
- Vehicle: Test substance fed by stomach tube as a 20% dispersion in 1%  "Tergitol" 7
- Post dose observation period: 14 days
Doses:
2,000; 2,520; 3,160; 3,980; 7,950 mg/kg bw, maybe additional doses
No. of animals per sex per dose:
10
Control animals:
not specified
Statistics:
Thompson, W.R. (1947): Use of moving averages and  interpolation to estimate median effective dose. Bact. Rev. 11, 115

Results and discussion

Effect levels
Sex:
male
Dose descriptor:
LD50
Effect level:
ca. 2 860 mg/kg bw
Mortality:
MORTALITY: LD50 = 2.86 (2.58-3.18) g/kg bw
Clinical signs:
CLINICAL SIGNS: 
Following the doses, the rats exhibited symptoms of  sluggishness, prostration, and narcosis. The urine had a brownish  coloration.
Gross pathology:
NECROPSY FINDINGS: 
A dose of 7950 mg/kg bw produced severe lung  hemorrhage, congestion of the liver, paleness of the kidney with edema in  some instances, 
opacity and adhesions of the intestines. Several of the  livers were jaundiced after the administration of a dosage of 3980 mg/kg  bw. This effect 
was not found at the higher level because of rapid death.  Lower dosage levels produced similar symptoms of lesser intensity.

Any other information on results incl. tables

MORTALITY: LD50 = 2.86 (2.58-3.18) g/kg bw
- Time of death: often delayed 3 to 4 days
- Number of deaths at each dose: 
  2,000 mg/kg bw:  1/10 (day 5)
  2,520 mg/kg bw:  2/10 (day 4)
  3,160 mg/kg bw:  3+2+2/10 (days 1, 3, 4)
  3,980 mg/kb bw:  3+2+3+2/10 (days 1, 2, 3, 4)


Applicant's summary and conclusion

Conclusions:
The feeding of tetrahydronaphthalene to male albinostrain rats resulted in a LD50 =2.86 g/kg bw (2.58 -3.18) based on a 14 day observation period. Thus tetrahydronaphthalene showed low acute toxicity in rats after oral gavage.
Executive summary:

The feeding of tetrahydronaphthalene to male albinostrain rats, without previous withdrawal of food, as a 20% dispersion in 1% "Tergitol" resulted in a LD50 =2.86 g/kg bw (2.58 -3.18) based on a 14 day observation period. Clinical signs included sluggishness, prostration and narcosis with deaths often delayed 3 to 4 days. The highest dose of 7.95 g/kg bw produced severe lung hamorrhage, congestion of the liver, paleness of the kidney with edema in some instances, opacity and adhesions of the intestines. Several of the livers were jaundiced after the administration of a dosage of 3980 mg/kg bw. This effect was not found at the higher level because of rapid death. Lower dosage levels produced similar symptoms of lesser intensity.