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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:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
According to the OECD SIDS document for potassium hydroxide (30 January 2002), a Klimisch 2 reliability score was assigned since the test procedure in accordance with national standard methods with acceptable restrictions. The OECD 425 guideline (acute oral toxicity, up-and-down procedure) is based on a revised ASTM version of the described procedure.
Cross-reference
Reason / purpose for cross-reference:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
A confirmatory study for the up-and-down method for acute oral toxicity testing
Author:
Bruce RD
Year:
1987
Bibliographic source:
Fund. Appl. Toxicol., 8, 97-100

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 425 (Acute Oral Toxicity: Up-and-Down Procedure)
Version / remarks:
This guideline is based on the procedure used in this study, but adopted en revised by ASTM (1987)
Principles of method if other than guideline:
* 14-day survival population conventional LD50 (conventional test) data were analyzed by the probit procedure of the SAS system (SAS Institute Inc., 1985)
* 1-week survival population conventional LD50 (up-and-down method)
data were analyzed by the method of maximum likelyhood (Dixon, 1965) using the SAS procedure NLIN
GLP compliance:
not specified
Test type:
other: up-and-down method and conventional dosing
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Potassium hydroxide
EC Number:
215-181-3
EC Name:
Potassium hydroxide
Cas Number:
1310-58-3
Molecular formula:
HKO
Details on test material:
- Name of test material (as cited in study report): potassium hydroxide

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Age at study initiation: no data
- Weight at study initiation: 190-300 g (weight variance is greater than the +/- 20% limit stated in OECD guideline 425)
- Fasting period before study: 18-20 hr prior to dosing
- diet after exposure: access to food ad libitum

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
not specified
Details on oral exposure:
dose is based on fasted body weight
Doses:
- conventional protocol (bruce 1985):
animals are dosed in groups of 10
geometric progression of 1.4 between successive dose groups
doses per time period: single dose

- up-and-down procedure:
animals are dosed singly (at least 1 day apart)
if animal dies or appears to be moribund the day after dosing, dose of next animal is decreased by a factor 1/1.3
if not, dose is increased by a factor 1.3
No. of animals per sex per dose:
10 animals per dose (conventional programme)
1 animal per dose (up-and-down method)
Control animals:
no
Details on study design:
- Duration of observation period following administration: 14 days (conventional programme), 1 week (up-and-down method)
- Necropsy of survivors performed: no data
- Other examinations performed: no data
Statistics:
* conventional test: data were analyzed by the probit procedure of the SAS system (SAS Institute Inc., 1985)
* up-and-down method: data were analyzed by the method of maximum likelyhood (Dixon, 1965) using the SAS procedure NLIN

Results and discussion

Effect levelsopen allclose all
Sex:
male
Dose descriptor:
LD50
Effect level:
333 mg/kg bw
95% CL:
270 - 376
Remarks on result:
other: conventional method, 1 week observation (without taking into account deaths during 2nd week)
Sex:
male
Dose descriptor:
LD50
Effect level:
388 mg/kg bw
95% CL:
288 - 523
Remarks on result:
other: up-and-down procedure (1 week observation)
Mortality:
-Number of deaths at each dose level: no data
-Some deaths observed during the second week after dosing. An LD50 of 273 mg/kg bw/d (214-324) was calculated based on the conventional method after a 2 weeks observation period. Since KOH is a strong alkaline substance, effects may occur even after a longer observation period due to the corrosive effects of the substance, leading to organ damage. However, this effect can not be considered as an acute effect.
Body weight:
-bw: 190-300 g
- Weight variation of rats was greater than the +/- 20% limit stated in OECD guidleine 425.
Other findings:
- Potential target organs: no data

Applicant's summary and conclusion

Interpretation of results:
other: no data
Remarks:
Criteria used for interpretation of results: not specified
Conclusions:
on the basis of one week observations: LD 50 for potassium hydroxide = 333 mg/kg (conventional method) and 388 mg/kg (up-and-down method)
Executive summary:

on the basis of one week observations: LD 50 for potassium hydroxide = 333 mg/kg (conventional method) and 388 mg/kg (up-and-down method).