Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

migrated 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: see 'Remark'

Remarks:

Study was conducted by a GLP accredited laboratory using a method compatible with OECD Testing Guideline 439. The study was conducted on Gas oil (polymer-derived), thermal cracked, full range, from which the registered substance is derived via steam stripping, and which is compositionally similar to the registered substance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Gas oil (polymer-derived). thermal cracked, full range

IUPAC Name:

Gas oil (polymer-derived). thermal cracked, full range

Constituent 2

Reference substance name:

700-882-3

EC Number:

700-882-3

IUPAC Name:

700-882-3

Constituent 3

Reference substance name:

Not assigned

IUPAC Name:

Not assigned

Test material form:

other: Liquid

Details on test material:

Name of test material: Gas oil (polymer-derived) thermal-cracked, full range
Physical state: Liquid
Substance type: UVCB

Test animals

Species:

other: Episkin reconstructed human epidermis model

Strain:

other: Episkin reconstructed human epidermis model

Details on test animals or test system and environmental conditions:

Episkin reconstructed human epidermis model. Episkin model kit supplied by SkinEthic Laboratories, Lyon, France on 23 April 2013.

Test system

Type of coverage:

other: The test item was applied topically to the corresponding tissues ensuring uniform covering.

Vehicle:

unchanged (no vehicle)

Controls:

other: Triplicate tissues treated with 10 µL of DPBS served as the negative controls and triplicate tissues treated with 10 µL of SDS 5% w/v served as the positive controls.

Amount / concentration applied:

TEST MATERIAL
Amount(s) applied (volume or weight with unit): 10 µL

Duration of treatment / exposure:

Exposure: 15 minutes
Post-exposure incubation: 42 hours

Number of animals:

N/A

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): Dulbecco's Phosphate Buffered Saline with Ca++ and Mg++
- Time after start of exposure: 15 minutes

SCORING SYSTEM: Optical density at 540 nm

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: Relative mean viability

Value:

114.5

Remarks on result:

other:

Remarks:

Basis: mean. Time point: 15 minute exposure. Reversibility: no data. Remarks: Relative mean viability is given in units of percentage (%). (migrated information)

In vivo

Irritant / corrosive response data:

Irritation response data is calculated based on the optical density of MTT at 540 nm. Viable cells can reduce the yellow tetrazolium salt to a blue formazan dye by mitochondrial succinate dehydrogenase. The quantity of viable cells depends on the irritation potential of the test item.

Any other information on results incl. tables

Item	OD(540) of tissues	Mean OD(540) of triplicate tissues	Standard Deviation of OD(540)	Relative individual tissue viability (%)	Relative mean viability (%)	Standard Deviation of Relative mean viability (%)
Negative Control Item (Dulbecco's Phosphate Buffered Saline with Ca++ and Mg++)	0.771	0.0748	0.021	103.1	100	2.9
	0.743			99.3
	0.729			97.5
Positive Control Item (Sodium Dodecyl Sulphate 5% w/v)	0.075	0.076	0.012	10	10.2	1.6
	0.065			8.7
	0.089			11.9
Test Item	0.888	0.856	0.043	118.7	114.5	5.7
	0.808			108
	0.873			116.7

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

The relative mean viability of the test item treated tissues was 114.5% after the 15-minute exposure period. The test item was considered to be a non-irritant.

Executive summary:

The in vitro skin irritation of the test substance was determined in accordance with the OECD Guideline for Testing of chemicals 439.

The principle of the assay was based on the measurement of cytotoxicity in reconstructed human epidermal cultures following topical exposure to the test item by means of the MTT reduction assay. The relative mean viability of the test item treated tissues was 114.5% after the 15-minute exposure period. The test item was considered to be a non-irritant.

Gas oil (polymer-derived), thermal-cracked, full-range and Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped are two very closely related substances. They consist of hydrocarbons having carbon numbers predominantly in the same range (C7 to C32) and boil over a very similar temperature range. The oils contain a relatively large proportion of substituted aromatic hydrocarbons (between 62 and 70%), particularly 1-ring aromatic hydrocarbons. Detailed analytical characterisation shows that the oils have a significant number of individual components in common. Both oils are produced by thermal cracking of the same range of hydrocarbon feedstocks at a temperature of 450-500°C. Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped differs from Gas oil (polymer-derived), thermal-cracked, full-range in that it has been through a steam-stripping process that removes a proportion of the lower boiling components. In addition to their composition and similar manufacturing process, testing has revealed that the two oils have very similar physico-chemical parameters, especially their solubility in water which is in the region of 3 mg/l suggesting that the two substances might be expected to behave similarly in biological and environmental aqueous environments.