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

Repeated dose toxicity: dermal

Administrative data

Endpoint:

repeated dose toxicity: dermal

Remarks:

other: expert assessment

Type of information:

other: Expert assessment

Adequacy of study:

key study

Study period:

2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: An assessment was conducted based on an examination of the toxicological properties of the components of the UVCB, supported by data from a read-across substance.

Data source

Reference

Reference Type:

other: expert assessment

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

An assessment was conducted based on an examination of the toxicological properties of the components of the UVCB, supported by data from a read-across substance.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

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

EC Number:

941-627-8

Molecular formula:

Not Applicable

IUPAC Name:

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

Constituent 2

Reference substance name:

Not assigned

IUPAC Name:

Not assigned

Test material form:

other: liquid

Details on test material:

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

Results and discussion

Effect levels

Dose descriptor:

NOAEL

Effect level:

25 mg/kg bw/day

Based on:

other: expert assessment

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified

Any other information on results incl. tables

The UVCB substance Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped has been assessed for potential local and systemic effects following a repeated exposure by the dermal route. Public data derived from other light fuel oils have been used, together with an assessment of components known to be present in the UVCB.

According to Feuston et al. (1994), there is a correlation between composition of a gas oil and local and systemic effects following a repeated dermal exposure. They highlighted a correlation between 2-ring aromatic compounds and local dermal effects, while aromatic compounds with 3 rings or more were more associated with systemic toxicity, and no correlation could be determined between toxic effects and the contend of the substances in 1-ring aromatic and nonaromatic compounds. Considering that Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped is mainly composed of 1- and 2-ring aromatics compounds, it is expected to be associated with local effects, while potential systemic effects would be driven by 1-ring aromatic and nonaromatic compounds.

According to the Lower Olefins and Aromatics REACH Consortium (2010), Benzene, Toluene, Ethyl benzene, and Styrene are expected to drive the toxicological effects of the registered substance following a repeated dermal exposure. However, they are only present at inconsequential, and therefore are not expected to induce significant systemic effects.

Limited information on the toxicity of the other compounds are available regarding the dermal route. Limonene is the identified individual compound present in the most important proportion, and is known to be a skin sensitiser but not for inducing systemic effects following a dermal exposure.

A subchronic toxicity study by dermal route has been performed on rats using the read-across substance Distillates (petroleum), light catalytic crack (API, 2012). Doses of 8, 25, 125, 500 and 1250 mg/kg bw of the substance were applied daily, 5 days a week, for 13 weeks (only 2 weeks for the group dosed at 120 mg/kg bw) with 10 animals/sex/dose. A skin irritation was observed in all the treated groups, with an increasing severity depending on the doses, which is expected considering the findings of Feuston et al. (1994). A significant reduction of bodyweight was observed at 500 mg/kg bw in females and at 125 and 500 mg/kg bw in males. Reduction of haemoglobin and haematocrit was observed at 500 mg/kg bw for both males and females. Reduction of several organs weight (including thymus) and increase of other organs weight (including liver) were observed at 125 and 500 mg/kg bw in males and at 500 mg/kg bw females.

It was therefore concluded that the NOAEL was 25 mg/kg bw for males and females, regarding local and systemic effects.

Considering that Distillates (petroleum), light catalytic cracked contains more 3-ring and more aromatic compounds when compared to the Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped, and that the composition of the registered substance contains a low quantity of substances known to induce systemic effects following a dermal exposure, the NOAEL of 25 mg/kg bw derived for the read-across substance may be considered as conservative, and may be applied to the registered substance.

Applicant's summary and conclusion

Conclusions:

Considering the toxicological properties of the components of the registered substance and the information derived from studies performed on a read-across substance, it has been proposed a NOAEL of 25 mg/kg bw for the registered. It has considered to be a conservative value.

Executive summary:

The UVCB substance Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped has been assessed for potential local and systemic effects following a repeated exposure by the dermal route. Public data derived from other light fuel oils have been used, together with an assessment of components known to be present in the UVCB.

This approach was considered as relevant as Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped is only used on secured industrial sites, under controlled conditions, by professional workers equipped with PPE. Therefore, only a limited exposure is expected by dermal route, which does not justify performing animal testing to evaluate the toxicity of the registered following a repeated dermal exposure.

According to Feuston et al. (1994), there is a correlation between composition of a gas oil and local and systemic effects following a repeated dermal exposure. They highlighted a correlation between 2-ring aromatic compounds and local dermal effects, while aromatic compounds with 3 rings or more were more associated with systemic toxicity, and no correlation could be determined between toxic effects and the contend of the substances in 1-ring aromatic and nonaromatic compounds. Considering that Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped is mainly composed of 1- and 2-ring aromatics compounds, it is expected to be associated with local effects, while potential systemic effects would be driven by 1-ring aromatic and nonaromatic compounds.

According to the Lower Olefins and Aromatics REACH Consortium (2010), Benzene, Toluene, Ethyl benzene, and Styrene are expected to drive the toxicological effects of the registered substance following a repeated dermal exposure. However, they are only present at inconsequential concentrations, and therefore are not expected to induce significant systemic effects. Limited information on the toxicity of the other compounds are available regarding the dermal route. Limonene is the identified individual compound present in the most important proportion, and is known to be a skin sensitiser but not for inducing systemic effects following a dermal exposure.

A subchronic toxicity study by dermal route has been performed on rats using the read-across substance Distillates (petroleum), light catalytic cracked (API, 2012). Doses of 8, 25, 125, 500 and 1250 mg/kg bw of the substance were applied daily, 5 days a week, for 13 weeks (only 2 weeks for the group dosed at 120 mg/kg bw) with 10 animals/sex/dose. A skin irritation was observed in all the treated groups, with an increasing severity depending on the doses. A significant reduction of bodyweight was observed at 500 mg/kg bw in females and at 125 and 500 mg/kg bw in males. Reduction of haemoglobin and haematocrit was observed at 500 mg/kg bw for both males and females. Reduction of several organs weight (including thymus) and increase of other organs weight (including liver) were observed at 125 and 500 mg/kg bw in males and at 500 mg/kg bw females.It was therefore concluded that the NOAEL was 25 mg/kg bw for males and females, regarding local and systemic effects.

Considering that Distillates (petroleum), light catalytic cracked contains more 3-ring and more aromatic compounds when compared to the Thermal cracking oil from blends of rubber, fuel oils and paraffin waxes, steam-stripped, and that the composition of the registered substance contains a low quantity of substances known to induce systemic effects following a dermal exposure, the NOAEL of 25 mg/kg bw derived for the read-across substance may be considered as conservative, and may be applied to the registered substance.