Dibutyl carbonate

Endpoint summary

Description of key information

Skin: not irritant (Epiderm)

Eye: risk of eye damage (HET-CAM)

Key value for chemical safety assessment

Skin irritation / corrosion

Link to relevant study records

Reference

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

July 2015

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

July 2012

Qualifier:

according to guideline

Guideline:

other: New guidance document on an integrated approach on testing and assessment (IATA) for skin corrosion and irritation, Series on Testing and Assessment No. 203

Version / remarks:

July 2014

GLP compliance:

yes (incl. QA statement)

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: B16Q060201
- Purity test date: 2017-01-02

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

Other:
pH value: 5

Test system:

human skin model

Source species:

human

Cell type:

non-transformed keratinocytes

Vehicle:

unchanged (no vehicle)

Details on test system:

RECONSTRUCTED HUMAN EPIDERMIS (RHE) TISSUE
- Model used: EPI-200 (MatTek)
- Tissue batch number(s): 23388

TEMPERATURE USED FOR TEST SYSTEM
- Temperature used during treatment / exposure: 25min at room temperature, 35min in the incubator at 37°C
- Temperature of post-treatment incubation (if applicable): 37°C (app. 42h)

REMOVAL OF TEST MATERIAL AND CONTROLS
The tissues were washed with sterile PBS to remove residual test material 1 hour after start of application. Rinsed tissues were blotted on sterile absorbent paper and transferred into new 6-well plates, pre-filled with 0.9 mL fresh medium. When all tissues were rinsed, the surface of each tissue was carefully dried with a sterile cotton swab.

MTT DYE USED TO MEASURE TISSUE VIABILITY AFTER TREATMENT / EXPOSURE
- MTT concentration: 1mg/ml
- Incubation time: 3h
- Wavelength: 570nm

FUNCTIONAL MODEL CONDITIONS WITH REFERENCE TO HISTORICAL DATA
- Viability: 1.4 (hc: 1-3)
- Barrier function: 6.73h (hc: 4.8 - 8.7h)
- Contamination: sterile

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

30µL undiluted

Duration of treatment / exposure:

1h

Duration of post-treatment incubation (if applicable):

app. 42h

Number of replicates:

3

Irritation / corrosion parameter:

% tissue viability

Value:

96.5

Negative controls validity:

valid

Positive controls validity:

valid

Interpretation of results:

GHS criteria not met

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not irritating)

Eye irritation

Link to relevant study records

Reference

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with national standard methods with acceptable restrictions

Principles of method if other than guideline:

HET-CAM

GLP compliance:

no

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: B323
- Purity test date: July 4, 2001

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Room temperature

OTHER SPECIFICS: Colorless liquid

Species:

chicken

Vehicle:

other: undiluted or as 10% solution in olive oil

Controls:

yes, concurrent positive control

Amount / concentration applied:

undiluted or as 10% solution in olive oil

Duration of treatment / exposure:

up to 301 seconds

Number of animals or in vitro replicates:

3 per test substance concentration
2 per positive control substance

Irritation parameter:

other: irritation index

Run / experiment:

unidluted

Value:

12.1

Positive controls validity:

valid

Irritation parameter:

other: irritation index

Run / experiment:

10% solution

Value:

0

Positive controls validity:

valid

Irritation parameter:

other: irritation index

Run / experiment:

positive control

Value:

>= 11.9 - <= 12.5

		Time (seconds) until appearance of			Irritation index
		Haemorrhagia	Lysis	Coagulation
undiluted	1	62	301	26	12.2
	2	67	301	38	11.8
	3	38	301	33	12.4
	Mean	55.7	301	32.3	12.1
10%	1	301	301	301	0
	2	301	301	301	0
	3	301	301	301	0
	Mean	301	301	301	0
NaOH	Mean	19.5	301	41	12.5
SDS	Mean	33.5	301	52.5	11.9

Interpretation of results:

other: Risk of serious eye damage

Endpoint conclusion

Endpoint conclusion:

adverse effect observed (irreversible damage)

Additional information

The potential of Dibutyl carbonate to cause dermal irritation was assessed by a single topical application of 30 μL of the undiluted test substance to a reconstructed three-dimensional human epidermis model (EpiDerm™).

Three EpiDerm™ tissues were incubated with the test substance for 1 hour followed by an 42-hours post-incubation period. The final mean viability of the tissues was 96.5%. It was concluded, that Dibutyl carbonate does not show a skin irritation potential in the EpiDerm™ in vitro skin irritation test under the test conditions chosen. No further test for skin corrosion is required.

This result is supported by the summary report of an older corrosion assay, in which no reduction in cell viability was observed after 3min or 1h.

In a HET-CAM test, undiluted dibutyl carbonate caused haemorrhagia and coagulation as quickly as the positive controls NaOH and SDS. It is consequently considered to cause severe eye damage. A 10% solution had no effect on the chorioallantoic membrane.

Justification for classification or non-classification

According to the available data, no classification is required for skin irritation, but the substance needs to be classified with Eye damage Cat. 1.