Hydrogen fluoride

Toxicity to terrestrial arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to non-target arthropods field studies (NTA other than pollinators)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Older, non-GLP publication.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

Not applicable

GLP compliance:

no

Application method:

soil

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
No further details.

Analytical monitoring:

no

Details on sampling:

Litter was collected from eight sites at distances as far as 33 km from an Al reduction plant in western Tennessee. Soil was collected at a level of 0 to 5 cm and 5 to 15 cm.

Vehicle:

no

Details on preparation and application of test substrate:

The main part of the study involves deducing whether the content of fluoride in the litter is related to the distance from thr Al reduction plant. In one test, sodium fluoride is added to the litter to determine the effect on mortality.

Test organisms (species):

Porcellus scaber

Details on test organisms:

No further details on test organisms.

Study type:

field study

Limit test:

no

Post exposure observation period:

No post observation period.

Test temperature:

Not stated

pH (if soil or dung study):

Not stated

Humidity:

Not stated

Photoperiod and lighting:

Not stated

Details on test conditions:

The test involves determining whether there is a link between distance from the Al reduction plant and concentration of fluoride ions in the soil. Litter was collected from eight sites at distances as far as 33 km from an Al reduction plant in western Tennessee. Soil was collected at a level of 0 to 5 cm and 5 to 15 cm. To determine the effect of increased fluoride concentration on mortality, a sample of litter was spiked with sodium fluoride and the mortality rate monitored.

Nominal and measured concentrations:

measured.

Reference substance (positive control):

no

Duration:

126 d

Dose descriptor:

NOEC

Effect conc.:

800 mg/kg bw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

Litter was collected from eight sites at various distances away from the plant. Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. Total acid extractable F- in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg). In a bioassay of litter from our study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable F-. When F- was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Results showed that litter collected far from the plant had a lower fiber content, was more sapric and was less acid. Total acid extractable F- in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg).

Validity criteria fulfilled:

not applicable

Conclusions:

Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. In a bioassay of litter from our study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable F-. When F- was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg.

Executive summary:

The effects of fluoride concentration were investigated on the numbers of Porcellio scaber in leaf litter. Leaf litter was collected from eight sites at various distances away from an aluminium reduction plant. Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. Total acid extractable F- in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg). In a bioassay of litter from study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable F-. When F- was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg.

Reference 2

Endpoint:

toxicity to non-target arthropods field studies (NTA other than pollinators)

Type of information:

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

Adequacy of study:

key study

Justification for type of information:

It is considered appropriate to address the toxicity to terrestrial arthropods data requirement for hydrogen fluoride (HF) by read-across to available data on sodium fluoride (NaF).

In water, HF dissociates rapidly to form hydrogen (H+) and fluoride (F−) ions, whereas NaF rapidly dissociate to sodium (Na+) and F- ions. Therefore, HF and NaF (as well as other fluorides) will dissociate rapidly to form F- ions in the environment (including moist soil), with any effects observed being directly attributable to the F- ion. The Na+ ion is naturally occurring and regulated by organisms (i.e. by homeostatic mechanisms) and consequently is not considered to have an impact on the read-across of ecotoxicological data. On this basis, the profile of HF is comparable to that of NaF with respect to the environment.

Reason / purpose for cross-reference:

read-across source

Duration:

126 d

Dose descriptor:

NOEC

Effect conc.:

800 mg/kg bw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

Litter was collected from eight sites at various distances away from the plant. Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. Total acid extractable F- in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg). In a bioassay of litter from our study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable F-. When F- was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

Results showed that litter collected far from the plant had a lower fiber content, was more sapric and was less acid. Total acid extractable F- in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg).

Validity criteria fulfilled:

not applicable

Conclusions:

Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. In a bioassay of litter from our study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable F-. When F- was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg.

Executive summary:

It is considered appropriate to address the toxicity to terrestrial arthropods data requirement for hydrogen fluoride (HF) by read-across to available data on sodium fluoride (NaF). In water, HF dissociates rapidly to form hydrogen (H⁺) and fluoride (F⁻) ions, whereas NaF rapidly dissociate to sodium (Na⁺) and F^- ions. Therefore, HF and NaF (as well as other fluorides) will dissociate rapidly to form F^- ions in the environment (including moist soil), with any effects observed being directly attributable to the F^- ion. The Na⁺ ion is naturally occurring and regulated by organisms (i.e. by homeostatic mechanisms) and consequently is not considered to have an impact on the read-across of ecotoxicological data. On this basis, the profile of HF is comparable to that of NaF with respect to the environment.

The effects of fluoride concentration were investigated on the numbers of Porcellio scaber in leaf litter. Leaf litter was collected from eight sites at various distances away from an aluminium reduction plant. Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. Total acid extractable F- in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg). In a bioassay of litter from study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable F-. When F- was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg.

Description of key information

A published study investigating the potential effects of fluoride on Porcellio scaber is available.

Additional information

The effects of fluoride concentration were investigated on the numbers of Porcellio scaber in leaf litter. Leaf litter was collected from eight sites at various distances away from an aluminium reduction plant. Results showed that litter collected far from the plant had a lower fibre content, was more sapric and was less acid. Total acid extractable fluoride in the litter and upper 15 cm of soil was about 41 times as much at the closest site (700 mg/kg) as at the most distant sites (12 and 16 mg/kg). In a bioassay of litter from study sites, woodlice (Porcellio scaber) had an abnormally high mortality in litter that contained 440 mg/kg or more of acid extractable fluoride. When fluoride was added in the form of NaF to the litter, a significant increase in mortality was observed only in treatments exceeding 800 mg/kg (Beyer et al, 1987).