Registration Dossier

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Administrative data

Description of key information

There are no specific neurotoxicity data on any of the streams within the category Aliphatics and Cyclics C5 and Higher or on the specific component substances benzene. However, both toluene and n-hexane are recognised as having significant neurotoxic activity. These effects are discussed in the section on repeated dose toxicity (5.6.3).

Key value for chemical safety assessment

Effect on neurotoxicity: via oral route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
Adequate information is available on the component substances to characterise the neurotoxic potential of these streams.

Effect on neurotoxicity: via inhalation route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
Adequate information is available on the component substances to characterise the neurotoxic potential of these streams.

Effect on neurotoxicity: via dermal route

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Quality of whole database:
Adequate information is available on the component substances to characterise the neurotoxic potential of these streams.

Additional information

Toluene exposure can produce central nervous system pathology in animals after high oral doses. In humans neuropsychological effects have been reported, particularly when exposures are not well controlled. There was no evidence that long-term exposure to toluene at 26 ppm for 21 years had any effects on cognitive function (Seeber et al, 2004).

In animals following oral or inhalation exposure n-hexane can produce neurologic dysfunction of motor or sensorimotor nerves resulting in weight loss and paralysis (Spencer and Schaumberg, 1985). Epidemiological studies on n-hexane have shown an association between inhalation exposure to n-hexane and neurological symptoms in occupationally exposed individuals. The NOAEC for peripheral neuropathy is reported to be 20 ppm (70 mg/m3) (HSE, 1990).

Reference

HSE (1990). N-Hexane occupational exposure standard. UK HSE


Justification for selection of effect on neurotoxicity via oral route endpoint:
The marker substances toluene and n-hexane have recognised neurotoxic activity. However controls to protect against the carcinogenicity of benzene (present at >0.1% in all streams) will mitigate such risks to the nervous system.

Justification for selection of effect on neurotoxicity via inhalation route endpoint:
The marker substances toluene and n-hexane have recognised neurotoxic activity. However controls to protect against the carcinogenicity of benzene (present at >0.1% in all streams) will mitigate such risks to the nervous system.

Justification for selection of effect on neurotoxicity via dermal route endpoint:
The marker substances toluene and n-hexane have recognised neurotoxic activity. However controls to protect against the carcinogenicity of benzene (present at >0.1% in all streams) will mitigate such risks to the nervous system.

Justification for classification or non-classification

See section 5.6 for overall classification for repeated dose toxicity.

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