Chemicals in cars and the need for safe alternatives

the Potential risks from Phthalates
in Auto interiors
studies have documented that phthalates used
in indoor plasticizers are found in indoor air and
dust, regardless of the ventilation rate. one study
noted, “[A] small area of plasticizer-containing products
emits almost as much as a large area. Therefore,
if the surface materials contain plasticizers, it is
impossible to avoid the phthalates in indoor air.” 47
The technical literature also documents the offgassing
of DEhP from soft PVC. Elevated interior air
temperature in cars, as high as 192°F, and dash board
temperatures as high as 248°F can cause accelerated
release of phthalates from materials and dramatic increases
in DEhP levels in the air (see Tables 11 and
12). At car interior temperatures of 140°F, DEhP levels
can reach extremely high levels. The combination of
high interior temperatures from parking in sunlight
and the off-gassing of DEhP, in particular, make
autos a significant source of phthalates being released
to the outdoor environment. A German study estimated
that 31% of the general population in that country may
be regularly exposed to DEhP at levels that exceed the
EPA reference dose. While no one has quantified in
detail the contribution of phthalates from dust and air
in cars to the total exposure, it is important to con-sider
that humans spend 101 minutes each day in their
vehicles and that continued releases of phthalates
contribute to overall environmental levels.
10 • T h E E C o l o G Y C E N T E R • t o x i C A t A n y s P e e d
Global production of phthalates is an estimated 3.5
million metric tons per year, 42 of which 80–90% is used
as additives in flexible pVC. 43 Roughly 50% of the
market share for phthalates is accounted for by diethylhexyl
phthalate (Dehp), 44 at least 95% of which is
added to pVC to give it flexibility. 45 As noted by koch
et al., “this is of greatest importance for public health
since Dehp is not only the most important phthalate
with respect to its production, use and occurrence and
omnipresence but also the phthalate with the greatest
endocrine disrupting potency.” 46