Report of the Persistent Organic Pollutants Review Committee on the work of its sixth meeting
Guidance on alternatives to perfluorooctane sulfonate and its derivatives
At its sixth meeting, the Persistent Organic Pollutants Review Committee endorsed guidance on alternatives to perfluorooctane sulfonate and its derivatives, on the basis of the draft guidance contained in document UNEP/POPS/POPRC.6/INF/8 as amended during the meeting. The text of the guidance as endorsed is set out below.
Guidance on alternatives to perfluorooctane sulfonate and its derivatives
The present document is a status report based on available information on alternatives to perfluorooctane sulfonic acid (PFOS) and its derivatives. It is important to note that toxicological and ecotoxicological data gaps remain with regard to potential alternatives to PFOS and its derivatives. The data presented in the document are only suggestive, and it is important that research continue with the aim of yielding additional health and environmental data that will enable a better understanding of the toxicological and ecotoxicological effects of the alternatives presented. The document responds to specific issues relating to the Stockholm Convention and does not address issues unrelated to persistent organic pollutants.
List of abbreviations and acronyms 5
Executive summary 9
I. Introduction, background and objectives 11
A. History of the proposal to list PFOS in the Stockholm Convention 11
B. Decision at the fourth meeting of the Conference of the Parties 11
C. Objective of the study 11
II. Characteristics of PFOS and its derivatives 11
A. PFOS related substances 11
B. Properties of PFOS related substances 13
C. Production and consumption of PFOS related substances 13
III. Alternatives to the use of PFOS 14
A. Textile impregnation and surface protection 14
B. Impregnation of packaging (paper/cardboard) 15
C. Cleaning agents, waxes and polishes for cars and floors 16
D. Surface coating, paint and varnish 16
E. Oil production and mining 17
F. Photographic industry 17
G. Electrical and electronic parts 18
H. Semiconductor industry 18
I. Aviation hydraulic fluids 19
J. Pesticides 19
K. Medical devices 20
L. Metal plating 20
M. Fire-fighting foams 22
N. Other uses 24
O. Summary of the information on alternatives to the use of PFOS 24
IV. Properties of alternative substances and hazard assessment 25
A. Overview 25
B. Shorter-chain perfluoroalkyl sulfonates 26
C. Shorter-chain perfluoroalkyl ketones and ethers 28
D. Polyfluorodialkyl ether sulfonates 28
E. Fluorotelomers and fluorophosphates 28
F. Fluorinated co-polymers 30
G. Fluorinated polyethers 31
H. Siloxanes and silicone polymers 32
I. Propylated aromatics 34
J. Sulfosuccinates 35
K. Stearamidomethyl pyridine chloride 36
L. Polypropylene glycol ether, amines and sulfates 36
V. Comparative assessment of PFOS and possible alternatives 37
VI. Conclusions, recommendations and future developments 38
Low surface tension is the key 38
Substitutes for PFOS are available 38
Need for better alternatives 38
Need for incentives 38
Complex assessment 38
Need for more public data and information on alternatives 39
Need for better communication in the value chain 39
Below is the decision taken by the Conference of the Parties of the Stockholm Convention at its fourth meeting on the listing of perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride. Acceptable purposes and specific exemptions are shown in the table.
SC-4/17: Listing of perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride
The Conference of the Parties,
Having considered the risk profile, risk management evaluation and addendum to the risk management evaluation for perfluorooctane sulfonate transmitted by the Persistent Organic Pollutants Review Committee,1
Taking note of the recommendation by the Persistent Organic Pollutants Review Committee to list perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride in Annex A or Annex B of the Convention,2
Decides to amend part I of Annex B of the Convention to list perfluorooctane sulfonic acid, its salts and perfluorooctane sulfonyl fluoride therein by inserting the following row, with the acceptable purposes and specific exemptions specified in the row:
Acceptable purpose or specific exemption
Perfluorooctane sulfonic acid (CAS No: 1763-23-1), its salts and perfluorooctane sulfonyl fluoride
Photo masks in the semiconductor and liquid crystal display (LCD) industries
Metal plating (hard metal plating)
Metal plating (decorative plating)
Electrical and electronic parts for some colour printers and colour copy machines
Insecticides for control of red imported fire ants and termites
Chemically driven oil production
Leather and apparel
Textiles and upholstery
Paper and packaging
Coatings and coating additives
Rubber and plastics
Also decides to create a new part III in Annex B called “Perfluorooctane sulfonic acid (PFOS), its salts, and perfluorooctane sulfonyl fluoride (PFOSF)”, which reads:
1. UNEP/POPRC.2/17/Add.5, UNEP/POPRC.3/20/Add.5 and UNEP/POPRC.4/15/Add.6.
Perfluorooctane sulfonic acid, its salts
and perfluorooctane sulfonyl fluoride
1. The production and use of perfluorooctane sulfonic acid (PFOS), its salts and perfluorooctane sulfonyl fluoride (PFOSF) shall be eliminated by all Parties except as provided in part I of this Annex for Parties that have notified the Secretariat of their intention to produce and/or use them for acceptable purposes. A Register of Acceptable Purposes is hereby established and shall be available to the public. The Secretariat shall maintain the Register of Acceptable Purposes. In the event that a Party not listed in the Register determines that it requires the use of PFOS, its salts or PFOSF for the acceptable purposes listed in part I of this Annex it shall notify the Secretariat as soon as possible in order to have its name added forthwith to the Register.
2. Parties that produce and/or use these chemicals shall take into account, as appropriate, guidance such as that given in the relevant parts of the general guidance on best available techniques and best environmental practices given in part V of Annex C of the Convention.
3.Every four years, each Party that uses and/or produces these chemicals shall report on progress made to eliminate PFOS, its salts and PFOSF and submit information on such progress to the Conference of the Parties pursuant to and in the process of reporting under Article 15 of the Convention.
4. With the goal of reducing and ultimately eliminating the production and/or use of these chemicals, the Conference of the Parties shall encourage:
(a) Each Party using these chemicals to take action to phase out uses when suitable alternatives substances or methods are available;
(b) Each Party using and/or producing these chemicals to develop and implement an action plan as part of the implementation plan specified in Article 7 of the Convention;
(c) The Parties, within their capabilities, to promote research on and development of safe alternative chemical and non chemical products and processes, methods and strategies for Parties using these chemicals, relevant to the conditions of those Parties. Factors to be promoted when considering alternatives or combinations of alternatives shall include the human health risks and environmental implications of such alternatives.
5. The Conference of the Parties shall evaluate the continued need for these chemicals for the various acceptable purposes and specific exemptions on the basis of available scientific, technical, environmental and economic information, including:
(a) Information provided in the reports described in paragraph 3;
(b) Information on the production and use of these chemicals;
(c) Information on the availability, suitability and implementation of alternatives to these chemicals;
(d) Information on progress in building the capacity of countries to transfer safely to reliance on such alternatives.
6. The evaluation referred to in the preceding paragraph shall take place no later than in 2015 and every four years thereafter, in conjunction with a regular meeting of the Conference of the Parties.
7. Due to the complexity of the use and the many sectors of society involved in the use of these chemicals, there might be other uses of these chemicals of which countries are not presently aware. Parties which become aware of other uses are encouraged to inform the Secretariat as soon as possible.
8. A Party may, at any time, withdraw its name from the Register of Acceptable Purposes upon written notification to the Secretariat. The withdrawal shall take effect on the date specified in the notification.
9. The provisions of note (iii) of part I of Annex B shall not apply to these chemicals.
At its fourth meeting the Conference of the Parties to the Stockholm Convention decided that the production and use of perfluorooctane sulfonic acid (PFOS), its salts and perfluorooctane sulfonyl fluoride (PFOSF) should be eliminated by all parties except for the use and production allowed as acceptable purposes and specific exemptions in accordance with Part III of Annex B to the Convention. While the PFOS-related chemicals used in practice are often precursors of PFOS and may not themselves be specifically listed in the Convention, their production and use is restricted by the listing of PFOS, its salts and PFOSF.
The objective of the present study is to summarize what is currently known about alternatives to PFOS, its salts and PFOSF, along with other substances produced where those substances are used as intermediates, and to enhance the capacity of developing countries and countries with economies in transition to phase out PFOS, its salts and PFOSF taking into account the need for longer phase-in schedules for alternatives for some uses and the fact that for certain uses no alternatives exist.
The present paper discusses the various uses of PFOS, its salts and PFOSFas a surfactant in impregnation, coating, metal plating, fire-fighting foams and the like and indicates where alternatives have been suggested, are available or have already been introduced to the market in some countries. Fluorinated or non-fluorinated alternatives exist for nearly all current uses. Available alternatives may not be ideal and are not necessarily economically and technically equivalent to PFOS; they may also pose environmental and health hazards at a certain level.
The key to the performance of fluorosurfactants is their extreme stability and low surface tension, which currently cannot be matched by other surfactants. The most optimal substance with regard to these properties is PFOS. Owing to environmental and health concerns regarding PFOS, however, other surfactants with or without fluorine could be used as alternatives in circumstances in which these properties are not needed to the degree that they are exhibited by PFOS. Given the relatively high prices of some fluorosurfactants, switching to alternatives can in some cases also have economic benefits.
The most common PFOS alternatives in use are fluorotelomers, which are precursors for perfluoroalkyl carboxylic acids (PFCA). Formerly the choice was often C8-fluorotelomers; those substances, however, have been shown to degrade into perfluorooctanoic acid (PFOA), whose hazardous properties are also cause for concern. 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 C6-, C4- and C3-perfluoroalkylated chemicals, which may be less hazardous.
For some uses non-fluorinated chemicals such as silicones, aliphatic alcohols and sulfosuccinates have been introduced as alternatives. In other cases particular uses or products are obsolete or could perhaps be changed so that they do not require PFOS; examples are digital techniques in the photographic industry and physical barriers in chrome plating.
A comparative assessment of PFOS and possible alternatives with regard to technical, social, economic, environmental, health and safety considerations is a very complex task requiring a large amount of data and other information – more than is normally available. Often the available information about PFOS is much more extensive than the available information about possible alternatives, which may be newly developed substances or formulations covered by trade secrets.
Furthermore, much of the information on a given alternative is often non-peer-reviewed and may be of relatively low scientific quality. A mechanism may be needed for continually updating information regarding the substitution properties and hazardousness of alternatives. Such a mechanism would be consistent with subparagraph 1 (b) of Article 9 of the Convention regarding the exchange of information on alternatives to persistent organic pollutants.
Available economic data may also be scarce and biased. The information received to date, however, suggests that alternatives are priced comparably to the PFOS-related compounds. Especially for coatings and paints, the non-fluorinated alternatives are cheaper.
PFOS and its derivatives are hazardous and, once released to the environment, will stay there forever since no degradation is foreseen; the final sink is likely to be the water bodies. As there is no possibility of recapturing emitted substances from the environment as a precaution all uses of PFOS globally should be limited, with a priority focus on uses resulting in high emissions.
Collecting and destroying existing stocks – for example, of PFOS-containing fire-fighting foams – instead of using them up, as is commonly done now, would prevent further contamination of areas (e.g. around airports). As long as PFOS is in a container it is likely that it will remain under control and cause no damage. Part III of Annex B of the Convention describes the goal of reducing and ultimately eliminating the production and use of the PFOS substances listed there.
There is a need for incentives for the development and application of safe, affordable and technologically feasible alternative substances and processes and to identify the driving forces for such development. The requirements of the Stockholm Convention that must be implemented in national legislation by all parties to the Convention can serve as an important tool for promoting such incentives.
Because of current restrictions governing PFOS, it is likely that closely related but unregulated chemicals could be manufactured commercially as alternatives. The risks posed by these substances, along with their socio-economic impacts, should be considered in deciding whether and how to regulate their use.
Increased efforts are needed to study the toxicological and environmental properties of alternatives and to make the resulting data and information trustworthy and public by subjecting it to peer review and publishing it in scientific journals.
PFOS and its alternatives are being studied and evaluated in parallel by authorities in many countries. Enhanced international cooperation will save resources and speed up these processes.
I. Introduction, background and objectives
A. History of the proposal to list PFOS in the Stockholm Convention
A letter of 14 July 2005 from the Swedish Ministry of the Environment proposed listing PFOS in Annex A to the Convention. A proposal to that end1 was discussed at the first meeting of the Persistent Organic Pollutants Review Committee in November 2005. The Committee concluded (decision POPRC-1/7) that the information on PFOS presented met the screening criteria specified in Annex D to the Convention. A PFOS risk profile was adopted at the Committee’s second meeting, in November 2006, and published on 21 November 2006.2 A risk management evaluation for PFOS3 was adopted at the Committee’s third meeting, in November 2007, and published on 4 December 2007. Finally, an addendum to the risk management evaluation was adopted at the Committee’s fourth meeting, in October 2008, and published on 30 October 2008.4
B. Decision at the fourth meeting of the Conference of the Parties
At its fourth meeting the Conference of the Parties decided to amend Annex B to list PFOS, its salts and PFOSF .5 Some acceptable purposes and specified exemptions were agreed upon because of a lack of alternatives for various uses, especially in developing countries and countries with economies in transition.
C. Objective of the study
The objective of the present study is to summarize what is currently known about alternatives to PFOS, its salts and PFOSF and to enhance the capacity of developing countries and countries with economies in transition to phase out PFOS, taking into account the need for longer phase-in times for alternatives for some uses and the fact that there are no alternatives for certain uses.
II. Characteristics of PFOS and its derivatives
A. PFOS related substances
The chemical names and CAS numbers listed in Annex B as PFOS, its salts, and PFOSF are summarized in table 1.