title: The toxicological effects of heavy fuel oil category substances.
abstract: Heavy fuel oil (HFO) category substances are used to manufacture HFO, a product used in industrial boilers and marine diesel engines. Commercial HFOs and blending stream components are substances of complex and variable composition, composed of C20 to >C50 hydrocarbons, although lower molecular weight material may be added to reduce viscosity and improve flow characteristics. An HFO blending stream (catalytically cracked clarified oil [CCCO]) was tested for target organ and developmental toxicity in rats following repeated dermal administration at doses of 5, 25, or 50 mg/kg/d. In the repeated dose study, there was evidence of increased liver weights, reduced thymus weights, and reductions in hematological parameters with an overall no observed adverse effect level (NOAEL) of 5 mg/kg/d. In the developmental toxicity test, there were significant reductions in fetal survival, significant increases in resorption frequency, and significantly reduced fetal weights with an overall NOAEL of 5 mg/kg/d. These target organ and developmental effects are associated with the types and levels of aromatic constituents in these substances. Among HFO blending streams, CCCOs have the highest levels of aromatics and, because they produce the characteristic toxicological effects at the lowest levels, are considered as "reasonable worst-case examples" for this group of substances. Other HFO category members with lower levels of aromatics produce similar effects but have higher NOAELs. The potential for target organ and developmental effects of other HFO category members can be predicted from information on the types and levels of the aromatic constituents present in these substances.
authors.affiliation: ExxonMobil Biomedical Sciences, Inc, 1545 US Highway 22 East, Annandale, NJ 08801, USA. Email: richard.h.mckee@exxonmobil.com.
authors.forename: Richard H
authors.initials: RH
authors.lastname: McKee
authors.forename: Fred
authors.initials: F
authors.lastname: Reitman
authors.forename: Ceinwen
authors.initials: C
authors.lastname: Schreiner
authors.forename: Russell
authors.initials: R
authors.lastname: White
authors.forename: Jeffrey H
authors.initials: JH
authors.lastname: Charlap
authors.forename: Thomas P
authors.initials: TP
authors.lastname: O'Neill
authors.forename: Katy Olsavsky
authors.initials: KO
authors.lastname: Goyak
mesh_terms: D000818:Animals; D001284:Atrophy; D004305:Dose-Response Relationship, Drug; D005260:Female; D005648:Fuel Oils / Q000633:toxicity*; D006838:Hydrocarbons / Q000032:analysis / Q000633:toxicity; D008099:Liver / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D019055:No-Observed-Adverse-Effect Level; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D012098:Reproduction / Q000187:drug effects; D012867:Skin / Q000187:drug effects* / Q000378:metabolism; D013950:Thymus Gland / Q000187:drug effects* / Q000378:metabolism; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D005648:Fuel Oils; D006838:Hydrocarbons
keywords: CAS number 64741-62-4; UVCB; catalytic cracked clarified oil; developmental toxicity; heavy fuel oil; petroleum substances; polycyclic aromatic hydrocarbon; repeated dose toxicity; toxicology models