Ammonium hydrogendifluoride

Genetic toxicity: in vivo

Administrative data

Endpoint:

in vivo mammalian germ cell study: gene mutation

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Reliability:

3 (not reliable)

Rationale for reliability incl. deficiencies:

other: Published study, poorly reported; non-standard methodology

Data source

Reference

Reference Type:

publication

Title:

The influence of atmospheric hydrogen fluoride on the frequency of sex-linked recessive lethals and sterility in Drosophila melanogaster

Author:

Gerdes RA

Year:

1971

Bibliographic source:

Fluoride 4(1): 25-29

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Exposure to 3 concentrations of hydrogen fluoride vapour to determine sex-linked recessive lethal mutations and sterility levels in Drosophila melanogaster.

GLP compliance:

no

Remarks:

: older publsihed study, pre-dates GLP

Type of assay:

Drosophila SLRL assay

Test material

Test material information

Constituent 1

Reference substance name:

Hydrogen fluoride

EC Number:

231-634-8

EC Name:

Hydrogen fluoride

Cas Number:

7664-39-3

IUPAC Name:

fluoride

Details on test material:

No further information.

Test animals

Species:

Drosophila melanogaster

Strain:

other: Oregon-r

Sex:

male/female

Details on test animals or test system and environmental conditions:

Oregon-r stocks of Drosophila melanogaster adults (8-12 hours old). Populations were maintained at stable densities by removing in sequence the food vials. Virgin "Basc" females were used to find sex-linked lethals.

Administration / exposure

Route of administration:

inhalation: vapour

Vehicle:

No vehicle was used.

Details on exposure:

Drosophila were exposed to hydrogen fluoride vapour in a fumigation chamber.

Duration of treatment / exposure:

24 hours for the sex-linked recessive lethal test. Sterility testing was conducted after 0, 3 and 6 weeks exposure.

Frequency of treatment:

Continuous during exposure period.

Post exposure period:

Matings were carried out over three 3-day brood periods. Egg samples were collected at 0, 3 and 6 weeks from initiation of fumigation.

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 1.3, 2.9 and 4.3 ppm
Basis:
nominal conc.
vapour

No. of animals per sex per dose:

No information.

Control animals:

yes, concurrent no treatment

Positive control(s):

Not examined.

Examinations

Tissues and cell types examined:

Not applicable.

Details of tissue and slide preparation:

Not applicable.

Evaluation criteria:

Sex-linked recessive lethals: The F1 generation from the treated males and Basc females were allowed to intermate and the females then sorted singly into vials. The absence of wild type males in the F2 generation was scored as a lethal.
Sterility: Each treated male and female was mated individually to a tester and these crosses were scored after 5 days for the presence of larvae. If no larvae were present the treated parent was transferred to a new vial and remated to a tester. After an additional 5 day period the flies in the vials without larvae were scored as sterile.

Statistics:

Lethal frequencies: Pearson and Hartley test for significance of observed differences between two Poisson variables.
Sterility: expressed as the percentage failure of adult Drosophila to produce viable larvae, ANOVA was used to determine significance of differences.

Results and discussion

Test results

Sex:

male/female

Genotoxicity:

positive

Remarks:

2.9 ppm and above

Toxicity:

not examined

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

not examined

Additional information on results:

No additional information.

Any other information on results incl. tables

The lethal frequency results of the three 3 -day broods were pooled. 1.3ppm hydrogen fluoride caused a non-significant increase in mutation frequency (0.015%) compared to controls. Significant increases in mutation frequency were observed at 2.9 and 4.3ppm concentrations. The percentage sterility was increased for both males and females, sterility increased with time and with concentration.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): ambiguous
Sub-lethal exposures to hydrogen fluoride vapour resulted in genetic aberrancies in Drosophila melanogaster, however the study was poorly reported therefore the significance of the results cannot be evaluated.

Executive summary:

Drosophila melanogaster were exposed to hydrogen fluoride vapour to investigate levels of mutagenicity caused by the substance. Significant increases in mutation frequency were observed at 2.9 and 4.3 ppm concentrations (24 hour exposure). The percentage sterility was increased for both males and females, sterility increased with time exposed (0, 3 and 6 weeks) and with concentration. The author concluded that sex-linked recessive lethals indicated an effect upon a specific chromosome, whilst the increase in sterility levels resulted from a broad effect upon the genome as a whole. However it must be noted that the study was poorly reported and therefore the significance of these results cannot be evaluated.