Potassium (E,E)-hexa-2,4-dienoate

Toxicity to soil macroorganisms except arthropods

Link to relevant study record(s)

Reference

Endpoint:

toxicity to soil macroorganisms except arthropods: short-term

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Justification for type of information:

Since sorbic acid is the corresponding acid to potassium sorbate, the substance in question, extrapolation of the obtained results is not considered to be restricted.

Qualifier:

according to guideline

Guideline:

OECD Guideline 207 (Earthworm, Acute Toxicity Tests)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method C.8 (Toxicity for Earthworms: Artificial Soil Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

signed 2003-12-08

Specific details on test material used for the study:

Name: Sorbic acid
Batch/ Lot number: 0000005661
GAB code: 20021004
Chemical name: trans, trans-2,4-hexadienoic acid
CAS number of a.s.: 110-44-1
Purity (nominal): 99 - 101 %
Purity (analysed): 99.8 %
Certificate of analysis: 13/03/2001
Expiry date: 11/03/2004
Appearance / Colour:
Storage conditions: cristalline powder / white
Control: deionized water





cristalline powder / white

Analytical monitoring:

no

Details on sampling:

not applicable

Vehicle:

no

Details on preparation and application of test substrate:

- Method of mixing into soil (if used): Pre-mixing with 10 g of quartz sand.
- Method of application to soil surface (if used): Direct blending of the sand/test substance mixture with dry artificial soil. Adjustment of soil moisture content to 35 % with deionised water.

Test organisms (species):

Eisenia fetida

Animal group:

annelids

Details on test organisms:

TEST ORGANISM
- Age at test initiation (mean and range, SD): 2–12 months
- Weight at test initiation (mean and range, SD): 300–600 mg

ACCLIMATION
- Acclimation period: 24 h acclimation to the untreated test substrate

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

no

Total exposure duration:

14 d

Post exposure observation period:

no data

Test temperature:

19–22 °C

pH:

5.6–6.1

Moisture:

29.7–35.3 %

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1 L glass jars
- Amount of soil or substrate: 0.75 kg wet weight/container
- No. of organisms per container (treatment): 10
- No. of replicates per treatment group: 4
- No. of replicates per control: 4

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Composition (if artificial substrate): 10 % sphagnum peat (pH 5.5–6.0), ‘Floratorf’, Floragard Vertriebs GmbH für Gartenbau, Oldenburg, Germany;
20 % kaolin clay (kaolinite content above 30 %), ‘Kaolin W gemahlen’, Erbslöh GmbH & Co.KG, Geisenheim, Germany; 69 % industrial sand, ‘Dorfner Quarzsand Nr. 9’, Goldmann Baustoffe GmbH & Co. KG, Pforzheim, Germany; approx. 1 % calcium carbonate – precipitated extra pure (soil pH adjusted to 6.0 ± 0.5 at the start of the test before adding the test item), Merck, Darmstadt, Germany
- Pre-treatment of soil: Dry components blended in an electric mixer.
- pH adjustment: Yes, prior to addition of the test substance by adding calcium carbonate .


OTHER TEST CONDITIONS
- Photoperiod: continuous lighting
- Light intensity: Artificial light, approx. 600 lux

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, lack of motility, burrowing activity, colour changes by visual examination 7 and 14 days after start of exposure

VEHICLE CONTROL PERFORMED: no

TEST CONCENTRATIONS
- Range finding study: yes
- Test concentrations: 10, 100, 200, 500, 1000 mg/kg soil dry weight
- Results used to determine the conditions for the definitive study: yes

Nominal and measured concentrations:

350, 455, 592, 769, 1000 mg/kg soil dry weight

Reference substance (positive control):

yes

Remarks:

2-chloroacetamide, 99.1 % purity, concentrations: 10, 18, 32, 56, 100 mg/kg

Key result

Duration:

14 d

Dose descriptor:

LC50

Effect conc.:

675 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Remarks on result:

other: 95 % CL = 647–703 mg/kg

Key result

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

455 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Key result

Duration:

14 d

Dose descriptor:

LC100

Effect conc.:

1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

mortality

Details on results:

- Range-finding study: No mortality up to 500 mg/kg.
- Controls: No control mortality.
- Mortality at end of exposure period: n=6 (592 mg/kg group), n=34 (769 mg/kg soil group) and n=40 (1000 mg/kg soil group)
- Changes in body weight of live adults (% of initial weight) at end of exposure period: There were no significant differences in body weight development.
- Morphological abnormalities: none
- Behavioural abnormalities: none
- Other biological observations: none

Results with reference substance (positive control):

LC50 was in the range between 10 and 18 mg/kg, thus corroborating the suitability of the test system.

Reported statistics and error estimates:

Body weight changes: ANOVA with Bonferroni test
LC50: Spearman-Kärber estimator

Table 3: Earthworm mortality after 14 d of exposure to sorbic acid in the range-finding test; n= 10 earthworms/replicate.

Sorbic acid [mg/kg]^1)	Number of dead earthworms	Mortality [%]
0 (control)^2)	0	0
10	0	0
100	0	0
200	0	0
500	0	0
1000^2)	56	93.3
^1)based on soil dry weight ^2)6 replicates

Table 4: Mortality data (main test).

Test substance concentration, nominal [mg/kg soil dry weight]	Mortality
	Number		Percentage
	7 d	14 d	7 d	14 d
Control	0	0	0	0
350	0	0	0	0
455	0	0	0	0
592	5	6	12.5	15
769	33	34	82.5	85
1000	40	40	100	100
Temperature [°C]:	19–22 °C
pH:	seeTable 2 above
Moisture content:	seeTable 1 above

 

Validity criteria fulfilled:

yes

Remarks:

Mortality of control animals < 10% . Since no deviations from the guidelines or other unusual circumstances were reported, the test was considered valid and reliable.

Conclusions:

Sorbic acid did not cause any adverse effects, mortality or effects on body weight up to concentrations of 455 mg/kg. The LC50 (14 d) was calculated as 675 mg/kg soil dw (647-703). Since the sorbate anion in the (eco-) toxicologically relevant moiety and its presence in dissociated or non-dissociated form is entirely determined by pH, extrapolation to potassium sorbate, the substance in question, is not considered to be restricted.

Executive summary:

The study according to the OECD 207 Guidelines was conducted with earthworms (Eisenia fetida), from in-house culture, adult worms (with clitellum, weight> 300 mg < 600 mg) less than one year old exposed to Sorbic Acid at 350, 455,592, 769, 1000 mg/kg soil for 14 days.  Worm mortality and behavioural effects at 7 and 14 d were assessed and weight chages were measured. The LC50 was determined to be 675 mg/kg soil dry weight.

Description of key information

LC50 = 675 mg/kg soil dry weight (Eisenia fetida, 14 days)
NOEC = 455 mg/kg soil dry weight (Eisenia fetida, 14 days)

Key value for chemical safety assessment

Short-term EC50 or LC50 for soil macroorganisms:

864 mg/kg soil dw

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

582 mg/kg soil dw

Additional information

In an acute toxicity tests with earthworms, the 14 -day LC-50 of sorbic acid was 675 mg/kg soil dry weight and the 14 -day NOEC was 455 mg/kg soil dry weight. Within the evaluation under the Biocidal Products Directive 98/8/EEC, the rapporteur member state Germany recalculated these endpoints to potassium sorbate, resulting in a 14 -day LC50 of 864 mg/kg soil dry weight and a NOEC of 582 mg/kg soil dry weight.