Although the table shows the opposite, C6-fluorochemistry alternatives may often be more expensive than C8-fluorochemistry alternatives, which are subject to a phase-out and therefore obsolete.
Especially at the beginning, alternatives might be more expensive to purchase or use; however, this increased cost could be an acceptable side effect of eliminating a very hazardous chemical. The prices of substitutes will decrease in the long run with a growing market and increasing competition.
The necessity or “public good” of a use could also be a factor in determining whether it should continue or be phased out even in the absence of apparently good alternatives. Of course PFOS has useful applications, but none for which feasible alternatives appear to be lacking.
VI. Conclusions, recommendations and future developments
Low surface tension is the key
In addition to stability, a key factor in the performance of fluorosurfactants is their extremely low surface tension, which currently cannot be matched with other surfactants. PFOS is the optimal substance with regard to that property. Owing to environmental and health concerns, however, surfactants without fluorine content could be used as alternatives if such low surface tension levels are not needed. Given the relatively high prices of fluorosurfactants, switching can in some cases also have economic benefits.
Substitutes for PFOS are available
Fluorinated or non-fluorinated alternatives exist for nearly all current uses of PFOS. While the alternatives may be slightly more expensive and less effective, they will normally be less hazardous. In Japan only three essential applications are left for PFOS: 1) etching agent for semiconductors, 2) semiconductor resists and 3) photo films for industrial purposes.86
The most common PFOS alternatives in use are fluorotelomers, which are precursors for PFCA. Formerly, C8-fluorotelomers were a frequent choice; they have been shown, however, to degrade into PFOA, which also has hazardous properties. For that reason the major global producers of fluorochemicals have agreed with the United States Environmental Protection Agency to phase out C8-fluorotelomers before 2015. As a result, there has been a shift to the less hazardous C6-, C4- and C3 perfluoroalkylated chemicals.
Need for better alternatives
For some uses non-fluorinated chemicals have been introduced as alternatives; examples include silicones, aliphatic alcohols and sulfosuccinates. It might also be that a particular use or product is no longer essential, or that a process could be changed to eliminate the need for PFOS, as has happened in the photographic industry and in chrome plating.
Need for incentives
There is a need for incentives to develop safe, affordable and technologically feasible alternative substances and processes and to identify the driving forces for their development. The international requirements applying to all parties to the Stockholm Convention, which must be implemented in national law, constitute one such incentive. The development of national law is an important tool for promoting incentives to identify and use alternative substances and processes. Postponing the development of national law until perfect alternatives are available is not wise because manufacturers may not develop alternatives if they are not forced to do so.
A comparative assessment of PFOS and its possible alternatives with regard to technical, socio-economic, environmental, health and safety considerations is a very complex process requiring a large amount of data and other information, and more than is normally available. Often the information available about PFOS is much more extensive than information about the possible alternatives, which may be newly developed substances or formulations covered by trade secrets. Furthermore, information on the alternatives will also often be non-peer-reviewed and of lower scientific quality. There may be a need for a mechanism for continuously updating information regarding the alternatives’ substitution properties and hazards. Such a mechanism should be consistent with Article 9, subparagraph 1 (b), of the Convention regarding the exchange of information on alternatives to persistent organic pollutants.
Available useful economic data may also be scarce and biased. The sparse information received to date, however, suggests that the alternatives are in general priced comparably to the PFOS-related compounds. Specifically in the coatings and paints area, the non-fluorinated alternatives are cheaper. Higher costs of alternatives are not always a problem; in fact, sometimes the high cost of not continuing the use of small amounts of PFOS can be a problem for the industry.
Need for more public data and information on alternatives
Much fewer data are currently available publicly on the alternatives than on PFOS. Much of the information is from patent literature, and the identities of actual chemicals used are often not disclosed. This reinforces the need for implementation of paragraph 1 of Article 9 on the information exchange regarding alternatives to persistent organic pollutants.
Chemicals with structures similar to those of the listed PFOS substances could cause concerns similar to those related to the latter substances. This should be considered in evaluating alternatives.
Increasing effort will be needed to study the toxicological and environmental properties of alternatives and to make the resulting information public and trustworthy by publishing it in peer reviewed scientific journals.
A strategic integrated approach to testing is needed to speed development of the data required to understand the issues and concerns relating to the various types of alternatives. According to the United States Environmental Protection Agency, testing can be done scientifically without necessarily testing every alternative chemical for every endpoint.
Need for better communication in the value chain
It is important that the issues associated with PFOS as a globally recognized persistent organic pollutant, including the health and environmental risks, be made fully known to suppliers and industries. Producers need to have better knowledge about the use of PFOS in processes, products and articles. It is also important to provide information to customers and consumers so that they can develop informed opinions about the possible need to change products or processes. Industries that are proactive in phasing out the use of a very hazardous chemical such as PFOS are likely to reap future market advantages.
Need for more international cooperation
PFOS and its substitutes are being studied and evaluated in parallel by authorities in many countries. More international cooperation can save resources and speed up processes. The OECD Parallel Process for the Notification of New Chemicals is one useful approach (for new chemicals) to consider in developing international collaboration on assessing potential alternatives to PFOS and other polyfluorinated chemicals of concern.
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