diesel fuel

1. Human
Epidemiologic studies of exposure to diesel exhaust
and occurrence of lung cancer provide evidence that is
consistent with a causal association. Overall, the hu-
man evidence for potential carcinogenicity for diesel
exhaust is considered to be strong, but less than suf-
ficient for diesel exhaust to be considered as a human
carcinogen because of exposure uncertainties (lack of
historical exposure data for exposed workers) and an
inability to address all potential confounding factors.
See also: Pollution Prevention Act, US; Polycyclic
Aromatic Hydrocarbons (PAHs); Respiratory Tract.
Further Reading
Kagawa J (2002) Health effects of diesel exhaust emission –
a mixture of air pollutants of worldwide concern. Toxi-
cology 27(181–182): 349–353.
United States Environmental Protection Agency (2000),
Health Assessment Document for Diesel Exhaust (EPA/
600/8-90/057E), July 2000.
Diesel Fuel
Shayne C Gad
& 2005 Elsevier Inc. All rights reserved.
* CHEMICAL ABSTRACTS SERVICE REGISTRY NUMBERS:
CAS 68334-30-5 (Diesel oil); CAS 68476-34-6
(Diesel fuel no. 2)
* SYNONYMS
* Diesel fuel (general) ¼ auto diesel, automotive
diesel oil (ADO), diesel engine road vehicle
(DERV), diesel, diesel fuel oil, gas oil
* Diesel fuel no. 1¼ no. 1 diesel, kerosene, arctic
diesel, diesel fuel oil no. 1, diesel oil no. 1, dipolar
* Diesel fuel no. 2 ¼ diesel fuel, diesel fuel oil no.
2, diesel oil no. 2
* Diesel fuel no. 4 ¼ marine diesel fuel, distillate
marine diesel fuel
* CHEMICAL/PHAMACEUTICAL/OTHER CLASS: Petroleum
hydrocarbon mixture of branched-chain alkanes,
cycloalkanes, aromatic compounds, and sulfuri-
zed esters
Uses
Diesel fuel no. 1 is primarily used in city buses. Diesel
fuel no. 2 is used in railcars, trucks, and boats. Diesel
fuel no. 4 is used in marine vessels.
Background Information
Diesel oil is a complex mixture produced by the dis-
tillation of crude oil. It consists of hydrocarbons
having carbon numbers predominantly in the range
of C9–C20 and boiling points in the range of B163–
3571C (325–6751F).
Diesel fuel no. 1 is a straight-run middle distillate
with a boiling range consistent with that of kerosene. It
contains branched-chain alkanes (paraffins), cycloalk-
anes (naphthenes), aromatics, and mixed aromatic
cycloalkanes. The boiling point range of diesel no. 1
largely eliminates the presence of benzene and polycy-
clic aromatic hydrocarbons (PAHs). Kerosene contains
less than 0.02% benzene and low levels of PAHs.
Diesel fuel no. 2 is a blend of straight-run and cat-
alytically cracked streams, including straight-run ker-
osene, straight-run middle distillate, hydrodesul-
furized middle distillate, and light catalytically and
thermally cracked distillates. The boiling range is
generally B160–3601C (320–6801F). Diesel fuel no. 2
is similar in composition to fuel oil no. 2. Some of the
PAHs contained in fuel oil no. 2, and therefore prob-
ably present in diesel fuel no. 2, include phenanthrene,
fluoranthene, pyrene, benz(a)anthracene, chrysene,
and benzo(a)pyrene.
Diesel fuel no. 4 is also called marine diesel fuel. It
is the most viscous of the diesel fuels and contains
higher levels of ash and sulfur. Diesel fuel no. 4 may
contain more than 10% PAHs.
Exposure Routes and Pathways
The most common exposure pathway is dermal
exposure from handling during transfer, fueling, and
repair of diesel-powered vehicles. Although the con-
stituents of diesel are not sufficiently volatile for in-
halation of vapors to be an exposure route of concern,
inhalation of diesel aerosols can occur. Ingestion of
diesel, often associated with aspiration into the lungs,
can occur as a result of accidental poisoning or suicide
attempts.
Toxicokinetics
Since diesel fuel is a mixture of numerous individual
substances, absorption, metabolism, and excretion
are very complicated and have not been completely
characterized. Systemic effects following dermal and
oral exposure and inhalation of diesel aerosols have
Diesel Fuel 19