Hydrogen fluoride

Toxicity to soil microorganisms

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil microorganisms

Type of information:

other: review

Adequacy of study:

key study

Study period:

24 to 63 days

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Recent review of published work on fluoride ions. Methodologcial data for individual studies are incomplete, however the studies have been assessed as part of the EU RAR and are therefore considered to be suitably reliable.

Reason / purpose for cross-reference:

reference to same study

Qualifier:

no guideline followed

Principles of method if other than guideline:

The EU RAR summarises the results of a number of relevant studies

GLP compliance:

no

Specific details on test material used for the study:

Not relevant

Analytical monitoring:

not specified

Details on sampling:

No details of sampling given in review.

Vehicle:

no

Details on preparation and application of test substrate:

No details on preparation and application of test substance given in the review.

Test organisms (inoculum):

soil

Total exposure duration:

63 d

Test temperature:

Not stated

Moisture:

Not stated.

Details on test conditions:

No further details given in review

Nominal and measured concentrations:

not stated

Reference substance (positive control):

no

Duration:

24 d

Dose descriptor:

NOEC

Effect conc.:

3 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Dehydrogenase inhibition

Remarks on result:

other: sodium fluoride

Remarks:

(Rogers and Li, 1985)

Duration:

63 d

Dose descriptor:

NOEC

Effect conc.:

340 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: NH4-minerilisation

Remarks on result:

other: potassium fluoride

Remarks:

(Van Wensem and Adema, 1991)

Duration:

63 d

Dose descriptor:

NOEC

Effect conc.:

106 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: NO3-mineralisation

Remarks on result:

other: potassium fluoride

Remarks:

(Van Wensem and Adema, 1991)

Duration:

63 d

Dose descriptor:

NOEC

Effect conc.:

1 060 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: P-mineralisation

Remarks on result:

other: potassium fluoride

Remarks:

(Van Wensem and Adema, 1991)

Details on results:

The NOEC values detailed in the report range from 106 to 3000 mg/kg. The 63 day experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber Latr. Nitrification was found to be the most sensitive in the micro-ecosystem test.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

The NOEC values detailed in the report range from 106 to 3000 mg/kg. The 63 d experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber. Nitrification was found to be the most sensitive in the micro-ecosystem test.

Validity criteria fulfilled:

not specified

Conclusions:

The NOEC values detailed in the report range from 106 to 3000 mg/kg. The 63 d experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber Latr. Nitrification was found to be the most sensitive in the micro-ecosystem test.

Executive summary:

The EU RAR reports NOEC values from 106 to 3000 mg/kg. The 63 day experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber. Nitrification was found to be the most sensitive endpoint investigated in the micro-ecosystem test.

Reference 2

Endpoint:

toxicity to soil microorganisms

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 soil microorganisms data requirement for hydrogen fluoride (HF) by read-across to available data on sodium fluoride (NaF) and potassium fluoride (KF).

In water, HF dissociates rapidly to form hydrogen (H+) and fluoride (F−) ions, whereas NaF and KF rapidly dissociate to F- ions and their respective counter ion (i.e. Na+ and K+, respectively). Therefore, HF, NaF and KF (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+ and K+ ions are 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 and KF with respect to the environment.

Reason / purpose for cross-reference:

read-across source

Duration:

24 d

Dose descriptor:

NOEC

Effect conc.:

3 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: Dehydrogenase inhibition

Remarks on result:

other: sodium fluoride

Remarks:

(Rogers and Li, 1985)

Duration:

63 d

Dose descriptor:

NOEC

Effect conc.:

340 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: NH4-minerilisation

Remarks on result:

other: potassium fluoride

Remarks:

(Van Wensem and Adema, 1991)

Duration:

63 d

Dose descriptor:

NOEC

Effect conc.:

106 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: NO3-mineralisation

Remarks on result:

other: potassium fluoride

Remarks:

(Van Wensem and Adema, 1991)

Duration:

63 d

Dose descriptor:

NOEC

Effect conc.:

1 060 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: P-mineralisation

Remarks on result:

other: potassium fluoride

Remarks:

(Van Wensem and Adema, 1991)

Details on results:

The NOEC values detailed in the report range from 106 to 3000 mg/kg. The 63 day experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber Latr. Nitrification was found to be the most sensitive in the micro-ecosystem test.

Results with reference substance (positive control):

Not applicable

Reported statistics and error estimates:

Not applicable

The NOEC values detailed in the report range from 106 to 3000 mg/kg. The 63 d experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber. Nitrification was found to be the most sensitive in the micro-ecosystem test.

Validity criteria fulfilled:

not specified

Conclusions:

The NOEC values detailed in the report range from 106 to 3000 mg/kg. The 63 d experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber Latr. Nitrification was found to be the most sensitive in the micro-ecosystem test.

Executive summary:

It is considered appropriate to address the toxicity to soil microorganisms data requirement for hydrogen fluoride (HF) by read-across to available data on sodium fluoride (NaF) and potassium fluoride (KF). In water, HF dissociates rapidly to form hydrogen (H⁺) and fluoride (F⁻) ions, whereas NaF and KF rapidly dissociate to F^-ions and their respective counter ion (i.e. Na⁺and K⁺, respectively). Therefore, HF, NaF and KF (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⁺ and K⁺ ions are 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 and KF with respect to the environment.

The EU RAR reports NOEC values from 106 to 3000 mg/kg. The 63 day experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber. Nitrification was found to be the most sensitive endpoint investigated in the micro-ecosystem test.

Description of key information

A number of studies are summarised and reveiwed in the EU RAR.

Key value for chemical safety assessment

Long-term EC10 or NOEC for soil microorganisms:

106 mg/kg soil dw

Additional information

The EU RAR reports NOEC values from 106 to 3000 mg/kg. The 63 day experiments were carried out in a micro-ecosystem containing poplar litter (30% o.m) and the isopod Porcellio scaber Latr. Nitrification was found to be the most sensitive endpoint investigated in the micro-ecosystem test.