Etidronic acid

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to soil macroorganisms except arthropods: long-term

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19 March 2014 - 15 May 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 222 (Earthworm Reproduction Test (Eisenia fetida/Eisenia andrei))

GLP compliance:

yes (incl. QA statement)

Analytical monitoring:

no

Vehicle:

no

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

28 d

Remarks:

Cocoons and offspring were incubated under the same conditions for further 4 weeks.

Test temperature:

20 ± 2 °C

pH:

6.0 ± 0.5

Moisture:

52% of the maximum water holding capacity

Nominal and measured concentrations:

62.5 – 125 – 250 – 500 – 1000 mg test item/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

Carbendazim

Key result

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

500 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

NOEC

Effect conc.:

472.5 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Duration:

28 d

Dose descriptor:

EC50

Effect conc.:

> 945 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

reproduction

Results with reference substance (positive control):

Significant effects between 1 and 5 mg a.i./kg soil dry weight.

Validity criteria fulfilled:

yes

Conclusions:

Under the conditions of this study, Etidronic acid hydrate did not induce evident mortality, pathological symptoms or changes of the behaviour of adult earthworms after 28 days of exposure in all tested concentrations. The adult earthworm biomass increased in the control and in all application rates without any statistically significant differences. After eight weeks of exposure the earthworm reproduction was not statistically significantly reduced at the test item concentrations 62.5, 125, 250 and 500 mg test item/kg soil dry weight. However, at 1000 mg test item/kg soil dry weight the reproduction rate was statistically significantly reduced.
The EC50 - value for reproduction was determined to be > 1000 mg test item/kg soil dry weight.

Thus, the No Observed Effect Concentration (NOEC) for Etidronic acid hydrate summarizing the endpoints mortality and body weight and reproduction of Eisenia fetida fetida after 8 weeks of exposure in artificial soil was determined to be 500 mg test item/kg soil dry weight.

Executive summary:

Effects ofEtidronicacidhydrate(Batch no.A3495) on mortality, biomass and the reproductive potential of the earthworm species Eisenia fetida (Annelida, Lumbricidae) were determined according to the Guidelines DIN ISO 11268-2 (1998), OECD 222 (2004) and BBA (1994). The study was conducted under static conditions over 8 weeks with the test item concentrations 62.5, 125, 250, 500 and 1000 mg test item/kg soil dry weight, which were mixed into artificial soil containing 10 % peat and a control using untreated artificial soil. 80 test organisms were inserted into 8 control replicates and 40 test organisms were divided into 4 replicates for each treatment (10 earthworms per replicate). They had an individual body weight between 0.32 and 0.54 g at experimental starting.

After 28 days of exposure in soil, no evident earthworm mortalities (< 10%) as well as no evident pathological symptoms or changes in the behaviour of adult earthworms were observed in all treatments. Moreover, no statistically significant differences in earthworm body weights were observed at all test item concentrations compared to the control. After further four weeks the reproduction rate (average number of juveniles produced) was 88 in the control and ranged between 46 and 115 in the test item treatment rates. Compared to the control, no statistically significant reduction of reproduction was observed at the test item concentrations 62.5, 125, 250 and 500 mg test item/kg soil dry weight. However, at 1000 mg test item/kg soil dry weight the reproduction was statistically significantly reduced. Overall, the NOEC of the test item concerning mortality, biomass and reproduction of earthworms was determined to be 500 mg test item/kg soil dry weight. The EC₅₀- value for reproduction was determined to be > 1000 mg test item/kg soil dry weight.

 

Reference 2

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

24-08-1990 to 07-09-1990

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to a test protocol that is comparable to the appropriate OECD test guideline, and in compliance with GLP. However no analytical monitoring was carried out.

Qualifier:

according to guideline

Guideline:

other: laboratory protocol, see below

Deviations:

yes

Remarks:

conducted as limit test, illumination lower lux than guideline due to use of lid on vessels, pH of soil not 6.5±0.5, test animals weighed between 200-570 g (not 300-600 as pre protocol)

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

not applicable

Principles of method if other than guideline:

Standard laboratory protocol: "Protocol for Conducting a Toxicity Test with Earthworms (Eisenia foetida)" (Protocol #061590/EISENIA.SA). This protocol closely follows the standard procedures described in the Food and Drug Administration, Center for Veterinary Medicine, Technical Assistance Handbook, Section 4 12 (US FDA, 1987), and the Assistance Guidelines from the Official Journal of the European Communities (No 133).

GLP compliance:

yes

Analytical monitoring:

no

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): The test substance was dispersed with deionised water. Artificial soil medlum and test substance are mixed thoroughly to ensure a homogeneous dispersion of the test material.

- Controls: the controls were exposed to water only.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM

- Common name: earth worms

- Source: Obtained from Carolina Biological Supply Company, Burlington, North Carolina. 

- Weight at test initiation (mean and range, SD): The worms used in the test came from a population having a mean weight of 330 mg (range 200-570 mg).


ACCLIMATION

- Acclimation period: Acclimated to test conditions for six weeks.

- Acclimation conditions (same as test or not): same as test

- Health during acclimation (any mortality observed): not reported

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Test temperature:

range: 19-22 degC

pH:

range: 6.4-7.2

Moisture:

Moisture content was approximately 29-35%

Details on test conditions:

TEST SYSTEM

- Test container (material, size): 1L glass vessels, covered with a perforated plastic lid

- Amount of soil or substrate: 500 g dry test medium

- No. of organisms per container (treatment): 10

- No. of replicates per treatment group: 4

- No. of replicates per control: 1

- No. of replicates per vehicle control: 1


SOURCE AND PROPERTIES OF SUBSTRATE

- Geographic location: artificial soil was used

- Composition (if artificial substrate): Comprised of 69% industrial sand, 20% kaolin colloidal powder, 10% sphagnum peat moss and approximately 1% calcium carbonate.


OTHER TEST CONDITIONS

- Photoperiod: 24 h light

- Light intensity: illuminated with 380-1200 lux, however effectively the soil surface received ca. 100 lux due to the lid of vessels allowing minimal passage of light.


EFFECT PARAMETERS MEASURED: Mortality and health observations made on days 7 and 14.


VEHICLE CONTROL PERFORMED: not necessary (vehicle was water)


TEST CONCENTRATIONS

- Spacing factor for test concentrations: conducted as limit test

- Justification for using less concentrations than requested by guideline: Selection of testing at 1000 mg AI/kg concentration for the definitive study with earthworms was consistent with the recommendations presented in FDA, March 1987, Environmental Assessment Technical Assistance Handbook, section 4.12.

- Range finding study

- Test concentrations: 0, 10, 100, 1000 mg AI/kg

- Results used to determine the conditions for the definitive study: 0% mortality at the highest concentration

Nominal and measured concentrations:

A single test concentration of 1000 mg active acid/kg was tested.

Reference substance (positive control):

yes

Remarks:

sodium lauryl sulphate

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

act. ingr.

Basis for effect:

mortality

Details on results:

- Mortality at end of exposure period: 97.5%. At test termination (day 14), one earthworm exposed to the treatment was missing and presumed dead.

- Other biological observations: Throughout the definitive test period, all surviving earthworms appeared healthy, with no morphological or behavioural abnormalities observed

Results with reference substance (positive control):

48 h LC50 for sodium lauryl sulphate: 1100 mg/l

Reported statistics and error estimates:

No effects of the test substance therefore no requirement for further statistical analysis.

Result expressed as nominal concentration. Properties of the test substance and evidence from other studies (where concentrations were measured) indicate that nominal and measured concentrations are likely to be in good agreement.

Validity criteria fulfilled:

yes

Conclusions:

A reliable 14 d LC50 value of >1000 mg active acid/ kg dw soil has been determined for the effects of HEDP acid on the earthworm E. foetida.

Description of key information

28-day NOEC value of 500 mg/kg soil dw for effects of HEDP-H on reproduction of Eisenia fetida (Noack, 2014).

Key value for chemical safety assessment

Long-term EC10, LC10 or NOEC for soil macroorganisms:

500 mg/kg soil dw

Additional information

An earthworm study following OECD Guideline 222 was conducted with HEDP-H (CAS 2809-21-4). The overall NOEC for HEDP-H was determined as 500 mg/Kg. The results of the new study well support the previously available results of a reliability 2 study on earthworm toxicity which determined a 14 d LC₅₀ value of >1000 mg/kg for the effects of HEDP sodium salt on the terrestrial worm E. foetida. It is also informative regarding the validity of the equilibrium partitioning approach for similar substances.