1,1'-methylenebis(4-isocyanatobenzene) and its oligomeric reaction products with butane-1,3-diol, 2,2'-oxydiethanol and propane-1,2-diol

Toxicity to terrestrial plants

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

toxicity to terrestrial plants: long-term

Data waiving:

other justification

Justification for data waiving:

other:

Reference 2

Endpoint:

toxicity to terrestrial plants: short-term

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP Guideline study but eight deviations from protocol are listed and no analytical monitoring reported.

Qualifier:

equivalent or similar to

Guideline:

OECD Guideline 208 (Terrestrial Plants Test: Seedling Emergence and Seedling Growth Test)

GLP compliance:

yes

Analytical monitoring:

not specified

Vehicle:

no

Details on preparation and application of test substrate:

An appropriate amount of coarse sand was coated with MDI (MDI added to acetone and mixed with sand which was subsequently dried for 2 days in furne-cupboard) and mixed with agricultural soil (ratio 1:1) to reach a concentration of 1000 mg MDI per kg of dry soil. Demineralized water added (ratio 1:1 on weight basis).

Artificial soil: mixture of natural soil from an orchard in Heerewaarden (The Netherlands) and coarse sand (grain size 50 to 1 000 µm) + 1.66 g K2HPO4; final pH of range: 5.0 - 7.5

Species:

Avena sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Oat: CEBECO, Roterdam (The Netherlands)

Species:

Lactuca sativa

Plant group:

Monocotyledonae (monocots)

Details on test organisms:

Lettuce: Rijk Zwaan (De Lier, The Netherlands)

Test type:

seedling emergence toxicity test

Study type:

laboratory study

Substrate type:

artificial soil

Limit test:

yes

Total exposure duration:

14 d

Post exposure observation period:

Test parameter: emergence, mortality, appearance and growth (weight).

Test temperature:

19°C (dark)
25 °C (light)

pH:

6.3 (at start)
6.4 (at end)

Moisture:

50%

Details on test conditions:

- Number of replicates, seeds per replicate: 10 seeds per cup containers, five replicates for both test containers and controls (one replicate for pH measurement). Five seeds removed from each cup after emergence.
- photoperiod: 16 hours
- light intensity: 6 000- 8 000 lux.
- control: yes (with acetone)

Nominal and measured concentrations:

1000 mg per kg of dry soil.

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

EC50

Effect conc.:

> 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

seedling emergence

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth

Species:

Avena sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Species:

Lactuca sativa

Duration:

14 d

Dose descriptor:

NOEC

Effect conc.:

>= 1 000 mg/kg soil dw

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

other: survival

Details on results:

No parameter significantly (5%) affected by test substance.

Description of key information

A 14d-EC50 of >1000 mg/kg soil (d.w.) was obtained for the test substance with the monocotyleous plants Avena sativa and Lactuca sativa according to OECD 208. Because MDI reacts rapidly with water to form predominantly insoluble and inert polyurea (Yakabe et al., 1994), no long-term toxicity tests with plants have been performed.

Key value for chemical safety assessment

Short-term EC50 or LC50 for terrestrial plants:

1 000 mg/kg soil dw

Additional information

The test substance is covered by the category approach of methylenediphenyl diisocyanates (MDI). Hence, data of the category substances can be used to cover this endpoint. A short-term toxicity study (van der Hoeven et al, 1992), carried out according to OECD 208, is available for PMDI for the monocotyleous plants Avena sativa and Lactuca sativa. In this limit test, a 14d-EC50 of >1000 mg/kg soil (d.w.) was obtained in artificial soil. The endpoint was based on emergence, mortality, appearance and growth (weight) of the plants.

No long-term terrestrial toxicity tests on terrestrial plants are available for the test substance. Because MDI reacts rapidly with water to form predominantly insoluble and inert polyurea (Yakabe et al., 1994), long-term toxicity tests with plants are not appropriate for the derivation of PNEC values.