Environmental Engineering Reference
In-Depth Information
2008). Values reported are 0.002-11 µg/l in bottles stored for over 70 days
for DMP, DEP, and DPP and 134 µg/l over 70 days for DEHP, at 25-30°C
(Bach et al., 2013), compared to approximately 6000 µg/l into water from
plasticized PVC containers (Mori, 1979).
Severalpossibleexplanationsfortheobservationhavebeensuggested:these
include contamination from plant and equipment (Higuchi et al., 2004),
water itself (Leivadara et al., 2008) or the filtration and purification system
(Li et al., 2010), poor storage conditions of water (Pinto and Reali, 2009),
and cross-contamination during recycling. However, Bicardi's (2003) study
where mineral water prior to bottling was obtained from plant and bottled
inPETandglassisinteresting.Nophthalateswereobservedupto8months'
storage in either sample, but water in PET bottles for periods longer than
9 months did show phthalates. Casajuna and Lacorte (2003) also did show
a similar result but with phthalates being detected in water only after 10
weeks of storage. This suggests the possibility of environmental phthalates
in indoor air (Bornehag et al., 2004), rainwater (Guidotti et al., 2000),
and interior of vehicles, partitioning into the PET bottle wall and being
transported into the water. The observations also support the possibility of
phthalates volatilized in ambient air partitioning into the PET bottle and
being transported across the bottle wall into the contents.
Exposure of PET bottles filled with water to sunlight over extended
durations is reported to result in accumulating degradation products on the
outer layer of the bottle. These include PET monomer and dimer. However,
over extended exposure period of up to 126 days, no degradation products
were detected in the bottles (Wegelin et al., 2001).
Residual antimony (Sb) from oxide (catalyst used in PET manufacture,
present in resin at 100-300 mg/kg resin) is an estrogenic substance (Sax,
2010) that can leach out of PET bottle into water (Shotyk and Krachler,
2007;Westerhoffetal.,2008b).Thelevelofitinbottledwaterisreportedto
be approximately 0.156-0.343 µg/l of water (Shotyk et al., 2006; Welle and
Franz, 2011). In common with phthalates, Sb levels in water also increases
on storage or incubation at high temperature (Keresztes et al., 2009;
Wagner and Oehlmann, 2009). The leachate concentrations achieved,
however, are well below the maximum contaminant level of 6 µg Sb/l set
by the USEPA, and what is leached out was mainly in the less toxic Sb(V)
formasopposedtoSb(III)form(Sánchez-Martínezetal.,2013).Thoughthe
Sb levels are low, developing antimony-free PET manufacturing processes
