Substitution of PFOS for use in nondecorative hard chrome plating

4.3.4 F-53
This chemical is a perfluorinated dialkyl ether sulfonate.
F
F
F
F
F
F
F
F
F
F
F
F
O
F
F
F
F
F
O
S
OH
O
Figure 4-4 F-53 – a perfluorinated dialkyl ether sulfonate
The CAS no. has not been traced. The ether group makes the chemical chain
degradable at that point resulting in shorter chain perfluorinated derivatives.
No data exists other than Chinese QSAR model results for persistence (halflives)
in water, sediment, soil, and air, bioconcentration factors (BCFs) and
toxicity to fish exist (see Table 4-1).
4.3.5 F-53B
This chemical is a chlorofluorinated dialkyl ether sulfonate.
Cl
F
F
F
F
F
F
F
F
F
F
F
O
F
F
F
F
F
O
S
O
O
K +
Figure 4-5 F-53B – a chlorofluorinated dialkyl ether sulfonate
The CAS no. has not been traced. The ether group and the chlorine
substitution make the chemical chain more degradable resulting in shorter
chain derivatives.
Chinese QSAR model results for persistence (half-lives) in water, sediment,
soil, and air, bioconcentration factors (BCFs) and toxicity to fish exist (see
Table 4-1).
4.3.6 Non-fluoro alternative
No information about the chemical substances in TIB Suract CR-H from
TIB Chemicals was available, as this is confidential.
4.3.7 Comparison
The adverse effects of PFOS have been extensively studied and much more
data exists on this chemical than on the available alternatives.
In general, the toxicity, persistence, and bioaccumulation of the perfluorinated
chemicals increase with the length of the alkyl chain. PFCs with a fluorinated
alkyl chain length of six (C 6 ) and below are not considered to be very
accumulative. This means that the fluorinated PFOS alternatives with a
shorter chain than PFOS will be less persistent, bioaccumulative, and toxic
than PFOS, and thus an improvement. The available data is insufficient for
prioritisation among the fluorinated alternatives. In Table 4-1 a few data is
shown.
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