BfR-Wissenschaft 
37 
7 Health effects of mineral oil, dispersants and oil-dispersant-mixtures 
Carolin Gràbsch 
Federal Institute for Risk Assessment (BfR), Berlin, Germany 
Introduction 
When assessing human health effects connected to the use of oil dispersants, three im 
portant aspects should be considered. First, during an oil spill, mineral oil is already there 
and an exposure to mineral oil is probable. Therefore, oil-mediated health effects for clean 
up worker are likely. Second; by using dispersants as chemical response to an oil spill, peo 
ple may additionally be exposed to those substances. Third; clean-up worker are exposed to 
oil-dispersant mixtures. Within the mixture, different constituents can interact and induce the 
toxic effect. 
Therefore, the assessment of health effects of oil-dispersant mixtures is performed stepwise 
in this article by looking on health effects of mineral oil only, toxicity data of dispersants as 
such and focusing on Deepwater Horizon as a case study for oil-dispersant-mixture toxicity. 
Health Effects of Mineral Oil 
Mineral oils consist of hundreds of compounds. The composition depends on the type of the 
mineral oil and is essential for understanding of resulting health effects. Relevant toxic com 
ponents are the large group of hydrocarbons, like the volatile organic compounds (VOCs) 
and the benzene, toluene, ethylbenzene and xylene fraction (BTEX), the more persistent 
PAHs and the huge group of aliphatic hydrocarbons. Furthermore, certain heavy metals and 
sulfur-containing substances are non-hydrocarbon components. The resulting health effects 
can be grouped in acute and chronic effects. Irritation of eye, skin and respiratory tract or the 
neurological impact are typical acute effects from volatile compounds after inhalation expo 
sure. Mutagenicity and carcinogenicity are examples for typical chronic effects after a PAH 
exposure. However, it is beyond the scope of this overview to discuss toxicity of oil compo 
nents. Here, we focus on oil-mediated health effects resulting from exposure related to oil 
spills. 
Table 7.1 : Assortment of oil spills (from CEDRE and ITOPF data basis, see references) 
Name 
Date 
Spill Size 
[kt] 
Oil Type 
Dispersants 
[t] 
Health related 
articles in interna 
tional per- 
reviewed journals 
Torrey Canyon 
18 m Mar. 1967 
119 
Crude oil 
10,000 
0 
Exxon Valdez 
24 m Mar. 1989 
37 
Crude oil 
yes 
6 
Braer 
4 m Jan. 1993 
85 
Crude oil 
130 
4 
Sea Empress 
15 m Feb. 1996 
72 
Light crude oil 
444 
2 
Erika 
11 m Dec. 1999 
20 
Heavy fuel oil 
no 
6 
Prestige 
13 m Nov. 2002 
63 
Heavy fuel oil 
no 
18 
Hebei Spirit 
7 th Dec. 2007 
10 
different Middle Eastern 
crude oils 
yes 
12 
Deepwater Hori 
zon 
20 th Apr. 2010 
500-1,000 
South Louisiana sweet 
crude oil 
~ 6700 
>30 
Public attention towards the history of oil spills began with the Torrey Canyon oil spill in 1967. 
From that time, a number of oil spills occurred (Table 7.1). Oil spills differ in spill size, oil type 
and the corresponding response or clean-up strategies.