Naphtha (Fischer-Tropsch), light, C4-10-branched and linear

Immunotoxicity

Administrative data

Endpoint:

immunotoxicity: short-term inhalation

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: peer reviewed international scientific journal

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Health assessment of gasoline and fuel oxygenate vapors: Immunotoxicity evaluation

Author:

K.L. White Jr. et al.

Year:

2014

Bibliographic source:

Regulatory Toxicology and Pharmacology (2014; in press). doi: 10.1016/j.yrtph.2014.04.010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.7800

Deviations:

not specified

Principles of method if other than guideline:

The study met the requirements of EPA’s guidelines for inhalation toxicity (EPA OPPTS 870.3465) and immunotoxicity screening (EPA OPPTS 870.7800).

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Baseline gasoline vapor condensate

IUPAC Name:

Baseline gasoline vapor condensate

Details on test material:

- Name of test material (as cited in study report): Baseline gasoline vapor condensate (BGVC)
- Composition of test material, percentage of components: see below "Any other information on materials and methods incl. tables", Tables 1 and 2
- Other: Test substance is closely related to 'Naphtha (Fischer-Tropsch), light, C4-10 - branched and linear', but it contains a higher level of aromatics, olefins and cycloparaffins. It can be assumed that the level of toxicity of 'Naphtha (Fischer-Tropsch), light, C4-10 - branched and linear', mainly consisting of branched and linear hydrocarbons is, however, considerably less (or at least the same) than that seen with the test material.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Administration / exposure

Route of administration:

inhalation: vapour

Vehicle:

air

Analytical verification of doses or concentrations:

yes

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

5 days/week

Doses / concentrations

Remarks:

Doses / Concentrations:
2000, 10000, 20000 mg/m3/day
Basis:
nominal conc.

No. of animals per sex per dose:

5 females

Control animals:

yes, concurrent vehicle

Applicant's summary and conclusion

Conclusions:

Exposure to the closely related test material ‘Baseline gasoline vapor condensate' (BGVC) did not result in significant changes in the IgM AFC response to sRBC, when evaluated as either specific activity (AFC/106 spleen cells) or as total spleen activity (AFC/spleen).

Executive summary:

Female Sprague Dawley rats were exposed via inhalation to vapor condensates of either gasoline or gasoline combined with various fuel oxygenates to assess potential immunotoxicity of evaporative emissions. Test articles included vapor condensates prepared from ‘‘baseline gasoline’’ (BGVC), or gasoline combined with methyl tertiary butyl ether (G/MTBE), ethyl t-butyl ether (G/ETBE), t-amyl methyl ether (G/TAME), diisopropyl ether (G/DIPE), ethanol (G/EtOH), or t-butyl alcohol (G/TBA). Target concentrations were 0, 2000, 10,000 or 20,000 mg/mg3 administered for 6 h/day, 5 days/week for 4 weeks. The antibody-forming cell (AFC) response to the T-dependent antigen, sheep erythrocyte (sRBC), was used to determine the effects of the gasoline vapor condensates on the humoral components of the immune system.

Exposure to the closely related test material ‘Baseline gasoline vapor condensate' (BGVC), G/MTBE, G/TAME, and G/TBA did not result in significant changes in the IgM AFC response to sRBC, when evaluated as either specific activity (AFC/106 spleen cells) or as total spleen activity (AFC/spleen).

Exposure to G/EtOH and G/DIPE resulted in a dose-dependent decrease in the AFC response, reaching the level of statistical significance only at the high 20,000 mg/m3 level. Exposure to G/ETBE resulted in a statistically significant decrease in the AFC response at the middle (10,000 mg/m3) and high (20,000 mg/m3) exposure concentrations.