Potassium cyanide

Acute Toxicity: other routes

Administrative data

Endpoint:

acute toxicity: other routes

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Experimental data was reviewed by the ECETOC Task Force, author of the JACC Report No. 53, “Cyanides of Hydrogen, Sodium and Potassium, and Acetone Cyanohydrin (CAS No. 74-90-8, 143-33-9, 151-50-8 and 75-86-5)”, 2007. The report is a weight of evidence approach to an extensive body of literature, much of which was undertaken prior to development of guidelines. The report was peer reviewed by the scientific non-governmental organization (NGO), which judged the data to be reliable with restrictions.

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

review article or handbook

Title:

Clinical and experimental toxicology of cyanides

Author:

Ballantyne B and Marrs TC

Year:

1987

Bibliographic source:

IOP Publishing, Wright, Bristol, UK, pp. 41-126.

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

Intraocular instillation in rabbits

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen cyanide

EC Number:

200-821-6

EC Name:

Hydrogen cyanide

Cas Number:

74-90-8

Molecular formula:

CHN

IUPAC Name:

cyanide

Test animals

Species:

rabbit

Strain:

not specified

Sex:

female

Administration / exposure

Route of administration:

other: intraocular

Vehicle:

water

Details on exposure:

Instillation volume is 0.03 ml.

Statistics:

95% Confidence Limits calculated.

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

ca. 1.04 mg/kg bw

95% CL:

> 0.96 - < 1.13

Mortality:

50%

Clinical signs:

Rapid breathing, weak and ataxic movements, convulsions, tonic spasms, irregular and shallow breathing, coma, cessation of breathing

Other findings:

Eye irritation develops, with mild chemosis and conjunctival hyperaemia which facilitates absorption. In surviving animals, the conjunctival effects become more marked and, by 24 hours, diffuse corneal opacification develops. These effects subside slowly, but mild conjunctivitis and keratosis are still present at 7 days post-instillation.

Any other information on results incl. tables

Time to onset of signs ranged from 30 to 60 seconds, and times to convulsions from 45 to 90 seconds. Time to death was 3 minutes.

There is no "first-pass" effect of metabolism with this route of administration.

Applicant's summary and conclusion

Conclusions:

The LD50 for intraocular instillation of HCN to rabbits is 1.04 mg/kg bw, with rapid onset of death, within minutes.
Hydrogen cyanide (Index No.006-006-00-X) and salts of hydrogen cyanides (Index No.006-007-00-5) are both listed in Annex VI, Table 3.1 of Regulation (EC) No. 1272/2008, entry 006-007-00-5, and are restricted in comparable ways taking into account physical characteristics. Thus, the assignment of potassium cyanide and sodium cyanide to a chemical category does not result in a less protective regulatory status.