Fuel oil, no. 4

Endpoint summary

Description of key information

Acute Oral Toxicity:

Acute oral toxicity of #2 home heating oil, was evaluated in male and female rats following a single oral gavage administration of the test material at different concentrations (similar to OECD 401).  The  LD50 for #2 home heating oil is 21.1 mL/kg body weight (approx 17,900 mg/kg). Based on all acute oral toxicity studies, the LD50 for VGOs/HGOs/Distillate fuels is > 5000 mg/kg bw.

Acute Inhalation Toxicity:

Acute inhalation toxicity of naval distillate in male and female rats was evaluated in a study involving whole-body exposure  for 4 hours (similar to OECD 403).  The acute inhalation LC50 was 4.1 mg/L .

Acute Dermal Toxicity:

In an acute dermal toxicity study, male and female New Zealand White rabbits were exposed to #2 home heating oil for 24 hours at a dose level of 5 mL/kg (approx 4300 mg/kg). The animals were then observed for 14 days (similar to OECD 402).  Based on this study, the acute dermal LD50 is > 4300 mg/kg.  

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 twelve good quality studies showing similar results

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

LC50

Value:

4 100 mg/m³ air

Quality of whole database:

one of ten studies showing similar results

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

4 300 mg/kg bw

Quality of whole database:

one of twelve studies showing similar resuts

Additional information

Acute Oral Toxicity:

In a key study ( API 1980a) the acute oral toxicity of #2 home heating oil was investigated. Undiluted material was administered to Sprague Dawley rats by gavage at doses of 10, 20, 22.5, 23, or 25 mL/kg body weight by gavage. In the animals administered #2 home heating oil, signs of toxicity were observed in all dose groups while severity also increased with increased dose.  Under the conditions of this study, #2 home heating oil had an oral LD50 of 21.1 mL/kg bw (approx 17,900 mg/kg).

 

In supporting studies conducted on numerous samples of the VGO/HGO/Distillate fuels category ( API 1980b, ARCO 1993a, 1993b, 1992a, 1987a, 1987b, 1987c, 1987d, 1985, 1973a; API 1980), rats were administered single oral gavage doses ranging from 1000 mg/kg to 11,400 mg/kg bw. LD50s for all studies were > 5000 mg/kg for males and females.

 

Based on these studies, the oral LD50 for VGOs/HGOs/Distillate fuels is > 5000 mg/kg bw.

 

Acute Inhalation Toxicity:

A key study investigated the effects of inhalation of naval distillate in male and female Sprague Dawley rats exposed by aerosol for 4 hours via whole body exposure at measured concentrations of 2.3, 3.5, or 4.9 mg/L aerosol (Klimisch score = 1, ARCO, 1988a). Animals were observed for 14 days. Clinical signs commonly included labored breathing and discharge from the nose and eyes. Decreased activity and mobility was reported at all concentrations during exposure. Macroscopic and microscopic findings included discoloration of the lungs and red staining around the snout of spontaneously dying animals. During the observation period, mortality was observed in 0 of 10, 4 of 10, and 4 of 10 male rats at measured exposures of 2.3, 3.5, and 4.9 mg/L, respectively. In females, mortality was observed in 1 of 10, 7 of 10, and 6 of 10 animals at the measured exposures of 2.3, 3.5, and 4.9 mg/L, respectively.  The inhalation LC50 was determined to be 5.4 mg/L in males, 3.6 mg/L in females, and 4.1 mg/L in combined sexes.

 

Supporting acute inhalation studies were performed on numerous samples of the VGO/HGO/SRGO/Distillate fuels category. These can be used to support the conclusions of the key study, which serves as a worst case scenario and provides an LC50 that can be used for classification purposes. In the supporting studies, rats were exposed via inhalation to VGOs/HGOs/Distillate fuels for 4 hours(Klimisch scores = 1). In general, LC50s as measured based on mortality and systemic effects were > 5.00 mg/L for aerosols (ARCO 1992b, 1988b, 1988c, 1988d, 1987e).  

Based on results of these studies,VGOs/HGOs/Distillate fuelsare classified as harmful by inhalation with an LC50 of 4.1 mg/L (aerosol). 

 

Acute Dermal Toxicity 

Multiple studies were available to assess the acute dermal toxicity of VGOs/HGOs/Distillate fuels. In the key study (Klimisch score = 1, API 1980b), the acute dermal toxic effects of #2 home heating oil were investigated. The study used eight New Zealand White rabbits (4 male/4 female) receiving 5 mL of applied test material.  Test material was applied under occlusive dressing to groups of 4 animals on intact or abraded skin. No signs of systemic toxicity were observed. Based on the lack of mortality, the LD50 is > 4300 mg/kg bw/day and the test material is not classified for acute dermal toxicity.

 

In supporting studies conducted on VGOs/HGOs/Distillate fuels(API 1980a, ARCO 1993d, 1992c, 1990a, 1987f, 1987g, 1987h, 1987i, 1986a), rabbits were administered single dermal doses of 2000 mg/kg bw or more (one study administered a dose of 1800 mg/kg bw). LD50s for all studies were greater than the maximum dose administered. In other acute dermal supporting studies (Klimisch score - 2, API 1980a, b), animals were administered a single dose of 5 mL/kg bw, which caused skin irritation and resulted in no obvious signs of toxicity during the 14-day observation period or at necropsy in the species examined.

 

Based on results of these studies, the dermal LD50 for VGOs/HGOs/Distillate fuels is > 4300 mg/kg bw.

Justification for selection of acute toxicity – oral endpoint

One of twelve acute oral toxicity studies, all showing LD50 values greater than 5000 mg/kg

Justification for selection of acute toxicity – inhalation endpoint

One of nine studies on members of the VHGO category

Justification for selection of acute toxicity – dermal endpoint

One of twelve acute dermal studies on VHGO category members

Justification for classification or non-classification

VGOs/HGOs/Distillate Fuels are not classified for acute oral toxicity based on an oral LD50 > 5000 mg/kg bw, according to the EU CLP Regulation (EC)1272/2008.  Based on acute inhalation data, VGOs/HGOs/Distillate Fuels are classified as H332 (harmful by inhalation) with an LC50 of 4.1 mg/L for male and female rats, according to the EU CLP Regulation (EC) 1272/2008.  VGOs/HGOs/Distillate Fuels are not classified for acute dermal toxicity based on a dermal LD50 of > 4300 mg/kg body weight for male and female rabbits, respectively, according to the EU CLP Regulation (EC) 1272/2008.

Regulatory classification and labelling for aspiration toxicity relies on the measured or calculated kinematic viscosity of a substance at 40°C rather than results from toxicological studies with animals. Hydrocarbons with kinematic viscosities less than or equal to 20.5 mms/sec are classified for aspiration toxicity according to the EU CLP Regulation (EC) 1272/2008. As members of this category may exist as low viscosity liquids that meet these criteria, substances in this category are classified for aspiration hazard unless the viscosity at 40^oC is greater than the regulatory thresholds based on the measured or calculated kinematic viscosities. 

Vacuum gas oils, hydrocracked gas oils, and distillate fuels having a kinematic viscosity of ≤20.5 mm²/s at 40°C would meet classification criteria as aspiration hazard (H304) under CLP.