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Toxicological information

Acute Toxicity: oral

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Administrative data

Endpoint:
acute toxicity: oral
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study is comparable to OECD Guideline 401 with acceptable restrictions (post exposure observation period 7 days, no necropsy and body weight data; unusual oral application)

Data source

Reference
Reference Type:
publication
Title:
Phenol Studies VI: The acute and comparative toxicity of phenol and o-, m-, and p-cresols for experimental animals
Author:
Deichmann WM, Witherup S
Year:
1944
Bibliographic source:
J Pharmacol Exp Ther 80: 233-240

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 401 (Acute Oral Toxicity)
Deviations:
yes
Remarks:
(post exposure observation period 7 days, no necropsy)
GLP compliance:
not specified
Test type:
standard acute method
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
reagent grade
Source: Merck
No further details

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female
Details on test animals and environmental conditions:
Source Wistar Institute but reared in conducting laboratory; food and water ad libitum.
No further data.

Administration / exposure

Route of administration:
oral: gavage
Details on oral exposure:
Test solution injected directly by a syringe into the oesophagus using a blunt hypodermic needle traversing the esophagus if the volume is <= 1ml; presumably gavage used for higher volume; post exposure observation period not clearly stated but presumably 7 days; different amounts of aqueous preparations containing 2, 5, 10 and 20% of phenol were administered to 5-15 rats per dose group (equal numbers of males and females).
Doses:
300-800 mg/kg bw (see Table below)
No. of animals per sex per dose:
5-15 (equal number of males and females in each group); see also Table below.
Control animals:
no
Details on study design:
Further details see Table below.
Statistics:
No data

Results and discussion

Effect levelsopen allclose all
Sex:
male/female
Dose descriptor:
LD50
Effect level:
530 mg/kg bw
Remarks on result:
other: 2 & 5% solution
Sex:
male/female
Dose descriptor:
LD50
Effect level:
540 mg/kg bw
Remarks on result:
other: 10% solution
Sex:
male/female
Dose descriptor:
LD50
Effect level:
340 mg/kg bw
Remarks on result:
other: 20% emulsion
Mortality:
All rats died within 3 to 150 minutes.(see Table below)
Clinical signs:
Twitching in eye muscles and those of eyelids and ears, then all over the body (extremities being the last); fluctuating body temperature (mostly subnormal), pulse and respiration rate increased and then became slow, irregular and weak; pupils first contracted and later on dilated; salivation, marked dyspnea, tremor and convulsions before death.
Body weight:
No data
Gross pathology:
No data

Any other information on results incl. tables

Oral toxicity in rats in relation to the concentration of aqueous phenol solution

Dose in mg/kg bw (number of rats)

Mortality (in %)

Time till death in minutes

2% Phenol in water (LD50 = 530 mg/kg bw)

400

1/5 (20)

25

500

4/10 (40)

15-150

600

7/10 (70)

19-50

700

8/10 (80)

14-60

800

10/10 (100)

10-90

5% Phenol in water (LD50 = 530 mg/kg bw)

400

1/15 (7)

20

500

6/15 (40)

10-30

600

11/15 (73)

3-80

700

9/10 (90)

4-50

10% Phenol in water (LD50 = 540 mg/kg bw)

500

4/10 (40)

15-35

600

6/10 (60)

10-50

700

9/10 (90)

10-120

800

9/10 (90)

7-60

20% Phenol in water (LD50 = 340 mg/kg bw)

300

6/15 (40)

5-45

400

9/15 (60)

15-60

500

15/15 (100)

5-55

Applicant's summary and conclusion

Conclusions:
After acute oral application in rats the LD50 varied between 340 and 540 mg/kg bw.
Executive summary:

The study is comparable to OECD Guideline 401 with acceptable restrictions (post exposure observation period 7 days, no necropsy and body weight data; unusual oral administration at application volumes <=1 ml).

Different amounts of aqueous solutions/emulsions containing 2, 5, 10 or 20% of phenol were orally administered to 5 -15 rats per dose group (equal numbers of males and females in each group). Phenol concentrations of 2, 5 or 10% resulted in the same degree of toxicity, the LD50 being 530, 530 or 540 mg/kg bw, respectively. The 20% emulsion was somewhat more toxic, the corresponding LD50 being 340 mg/kg bw. All of the animals that died within the study were found dead within 3 to 150 minutes. Clinical signs were twitching in muscles (starting with eye muscles), hypothermia, altered pulse and respiration rate (increased and later slow, irregular and weak), pupils first contracted and later on dilated, salivation, marked dyspnea, tremor and convulsions before death.

Conclusion: After acute oral application in rats the LD50 varied between 340 and 540 mg/kg bw.