Isoheptane

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Endpoint:

toxicity to terrestrial plants: long-term

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Adopted according to OECD SIDS (public available peer reviewed source) and respective study summary. The original source is not available and has not been reviewed.

Justification for type of information:

A discussion and report on the read across strategy is given as an attachment in IUCLID Section 13.

Reason / purpose for cross-reference:

read-across: supporting information

Principles of method if other than guideline:

Although a specific standard guideline was not used, the test method generally followed standard test procedures, however, less specific analytical information was provided than is desirable. Growth of lettuce seeds was followed in one test conducted in soil and a second test in a nutrient solution. Two tests each were run in parallel in two different labs.

GLP compliance:

no

Analytical monitoring:

yes

Vehicle:

yes

Details on preparation and application of test substrate:

- Chemical name of vehicle: acetone and/or small amount of quartz sand (in soil experiment) and tributylalcohol in nutrition solution experiment

Species:

Lactuca sativa

Plant group:

Dicotyledonae (dicots)

Details on test organisms:

- Common name: lettuce
- Plant family: Asteraceae
- Variety: Ravel R2
- Source of seed: Orchard

Test type:

early seedling growth toxicity test

Study type:

laboratory study

Substrate type:

other: natural soil and nutrient solution

Limit test:

no

Total exposure duration:

21 d

pH:

7.5 (soil test)

Moisture:

25 to 30% (soil test)

Details on test conditions:

TEST SYSTEM
- Testing facility:
- Test container (type, material, size): The soil test systems were covered with glass plates until germination occurred to prevent moisture loss. After germination, the plates were removed and moisture loss was control by adding demineralized water back to the soil. In the Nutrient Solution Experiment seeds were placed on plastic trays, which contained perlite that was saturated with nutrient solution. The trays were covered with glass plates to reduce volatile loss during germination
- No. of plants (retained after thinning): 5 (soil test)
- No. of replicates per treatment group: 2 (in both tests)
- No. of replicates per control: 2 (in both tests)

SOURCE AND PROPERTIES OF SUBSTRATE (if soil)
- Soil texture (if natural soil)
- % clay: 12
- % organic matter: 1.4
- Maximum water holding capacity (in % dry weigth): 80


NUTRIENT MEDIUM (if used)
- Description: 3.73 mM Ca(NO3); 4.40 mM KNO3; 0.97 mM KH2PO4; 1.92 mM MgSO4; 0.89 mM K2SO4; trace elements and FeEDTA (per Steiner A, 1968. Soilless culture. Proceedings, Sixth Colloquium of the International Potash Institute, Florence, Italy, pp. 342-341.).


TEST CONCENTRATIONS
- Spacing factor for test concentrations: 3.2 (both tests)

Nominal and measured concentrations:

1000 mg/kg (soil test) (nominal)

Species:

Lactuca sativa

Duration:

7 d

Dose descriptor:

other: EL50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: soil test; No effects at the highest concentration tested.

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

other: EL50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Remarks on result:

other: soil test; No effects at the highest concentration tested.

Reported statistics and error estimates:

EC50 values for substances that showed effects were determined based only on harvested shoots and calculated by applying a logistic model (per Haanstra et al., 1985. The use of sigmoidal dose response curves in soil ecotoxicological research. Plant Soil 82, 293-297.)

Nutrient Solution Test Results:
Day 16 or 21 EC50 = no effects at limit of solubility under the test conditions.

Validity criteria fulfilled:

yes

Conclusions:

The lettuce plant (Lactuca sativa) did not exhibit toxic effects when exposed to the test substance added to soil or aqueous nutrient solutions containing the test substance. Results from the soil and nutrient solution tests are summarized as follows:

Soil:
Days 7 and 14 EL50 >1000 mg/kg soil (dry weight), based on nominal concentrations. No effects at the highest concentration tested.

Nutrient Solution:
Day 16 or 21 EC50 = no effects at limit of solubility under the test conditions.

Executive summary:

The lettuce plant (Lactuca sativa) did not exhibit toxic effects when exposed to the test substance added to soil or aqueous nutrient solutions containing the test substance. Results from the soil and nutrient solution tests are summarized as follows:

Soil:

Days 7 and 14 EL50 >1000 mg/kg soil (dry weight), based on nominal concentrations. No effects at the highest concentration tested.

Nutrient Solution:
Day 16 or 21 EC50 = no effects at limit of solubility under the test conditions.

Description of key information

There is no data available for this substance. However, key and supporting data is available for structural analogues Octane. The data is read across to this substance based on analogue read across and a discussion and report on the read across strategy is provided as an attachment in IUCLID Section 13. Key information is summarised below:

 

The test substane Octane did not exhibit toxic effects in lettuce plant (Lactuca sativa). The study reported a 14 -day EL50 of >1000 mg/kg soil (dry weight), based on nominal concentrations. There were no effects at the highest concentration tested.

Additional information

The study from Hulzebos et al. (1993) examined the effect of Octane on the lettuce plant (Lactuca sativa). No toxic toxic effects were observed at the hughest concentration tested and the reported results from the soil and nutrient solution tests are summarized as follows:

Soil:

Days 7 and 14 EL50 >1000 mg/kg soil (dry weight), based on nominal concentrations.

Nutrient Solution:
Day 16 or 21 EC50 = no effects at limit of solubility under the test conditions.