Naphtha (petroleum), hydrotreated heavy

Endpoint summary

Description of key information

The acute toxicity of members of the low boiling point naphtha category has been investigated in a large number of animal studies (44 oral/dermal and 38 inhalation). Around 20 individual CAS RNs from the category have been tested, and the acute toxicity can be summarised as follows:

Acute toxicity – Oral LD50 > 5000 mg/kg (OECD TG 401)

Acute toxicity – Dermal LD50 > 2000 mg/kg (OECD TG 402 under occlusive conditions)

Acute toxicity – Inhalation LC50 > 5610 mg/m3 (OECD TG 403)

Key value for chemical safety assessment

Acute toxicity: via oral route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

5 000 mg/kg bw

Quality of whole database:

One of 43 acute toxicity studies carried out on members of the Low boiling point naphtha category

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LC50

Value:

5 610 mg/m³ air

Quality of whole database:

one of 39 studies on the acute inhalation toxicity of low boiling point naphthas

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Quality of whole database:

one of 44 well conducted studies on lo boiling point naphthas

Additional information

The acute toxicity of members of the low boiling point naphtha category has been investigated in a large number of animal studies (44 oral/dermal and 38 inhalation). Around 20 individual CAS RNs from the category have been tested and show similar result, summarised as follows:

Acute toxicity – Oral LD50 > 5000 mg/kg (OECD TG 401)

Acute toxicity – Dermal LD50 > 2000 mg/kg (OECD TG 402 under occlusive conditions)

Acute toxicity – Inhalation LC50 > 5610 mg/m3 (OECD TG 403)

Human evidence also indicates that gasoline has very low acute oral, dermal or inhalation toxicity. However, it can produce severe injury if taken into the lung as a liquid, and there may be profound central nervous system depression following prolonged exposure to high levels of vapor. Laboratory animals respond similarly to humans. Neither gasoline itself, nor any of the naphtha blending stocks produces acute oral, dermal or inhalation toxicity under conditions defined by regulatory testing protocols.

Justification for selection of acute toxicity – oral endpoint

one of a large number of studies showing LD50 > 5000 mg/kg

Justification for selection of acute toxicity – inhalation endpoint

one of a large number of acute studies by the inhalation route

Justification for selection of acute toxicity – dermal endpoint

one of a number of studies showing acute dermal LD50 > 2000 mgkg

Justification for classification or non-classification

Although most of these studies were conducted many years ago, they were generally, conducted in accordance with regulatory guidelines good laboratory practice recommendations. The data are this considered adequate for regulatory purposes and no additional testing is warranted.

Acute inhalation toxicity:

It is acknowledged that the Key study was only tested up to a targeted nominal concentration of 5 mg/L (at the time the study was conducted, the recognised limit value).  This study, along with the weight of evidence from supporting studies, show no mortality at this dose level.  Additionally, there are two inhalation repeated tox studies of good reliability (reliability 1) where rats were exposed 6 hours per day for 13 weeks to vapor concentration of Naphtha up to levels of 20 mg/L, with no treatment related mortalities.  Therefore, no classification for acute inhalation toxicity is warranted.

The data do not meet the criteria for hazard classification for acute, dermal or inhalation toxicity according to EU CLP Regulation (EC No. 1272/2008); however, warnings for aspiration hazard and potential narcotic effects at high concentrations should be considered.