An Environmentalist's Vision of Operationalizing 

the Precautionary Principle in the Management of Chemicals

Gwynne Lyons, BPharm, Andreas Ahrens, MSC, Elizabeth Salter-Green, MA

International Journal of Occupational and Environmental Health Oct/Dec00 v.6, n.4

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In Europe and elsewhere, there is compelling evidence that humans, wildlife, and the environment are being damaged by man-made chemicals. Recognizing that regulatory initiatives are needed to try to prevent harm before it occurs in the future, the precautionary principle has become a focus of attention on both sides of the Atlantic. The authors suggest a way to implement the precautionary principle in the management of chemicals, outlining how this guiding principle can be given a practical relevance within regulatory initiatives to reduce the risks posed by chemicals currently traded in the European Union and elsewhere. Key words. precautionary principle; chemicals management; legislation; overarching principle; comparative assessment; substitution principle.

INT J OCCUP ENVIRON HEALTH 2000;6:289-295

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Received from the WWF-UK (World Wide Fund for Nature), Norwich, England (GL); Okopol, Institute for Ecological Assessment and Environmental Policy Ltd., Hamburg, Germany (AA); and WWF European Policy Office, Brussels, Belgium (ESG).

Address correspondence and reprint requests to: Gwynne Lyons, Toxics And Policy Advisor to World Wide Fund for Nature (WWF-UK), 17 The Avenues, Norwich NR2 3PH, England; telephone: -441603-507363; fax: -44-1603-507363; e-mail:  g.lyons@mcmail.com

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There is compelling evidence that humans, wildlife, and the environment in Europe and elsewhere are being damaged by man-made chemicals. Recognizing that regulatory initiatives are needed to try to prevent harm before it occurs in the future, the precautionary principle has become a focus of attention on both sides of the Atlantic.

This article suggests a way to implement the precautionary principle in the management of chemicals. It outlines how this guiding principle can be given a practical relevance within regulatory initiatives to reduce the risks posed by chemicals currently traded in the European Union (EU) and elsewhere.

The rest of the article is organized as follows. First, the main legal texts that determine the application of precaution in the EU and some of the Commission of the European Communities' (The Commission's) thinking on the subject are outlined. It is argued that the Commission's Communication on the Precautionary Principle, of February 2000,¹ wrongly ascribes the application of the precautionary principle as being part of risk management, rather than as an overarching principle.

The second section sets out an environmentalist's vision of the precautionary principle. The precautionary principle is seen an overarching mechanism to lower the risk that chemicals pose by:

1. ensuring that chemicals lacking hazard data are not marketed;

2. taking account of the needs and acceptance of risk expressed by society;

3. aiming to achieve a high level of protection (for example, hazardous substances originating from human activity should not be found in breast milk or in the open seas),

4. ensuring that the least risky option is chosen to deliver the goods or service, and giving preference to risk reduction through substitution rather than emission control;

5. basing the quantification of risk on worst-case assumptions; and

6. taking action without delay based on the best available knowledge at the time and giving preference to human health and the environment rather than the economic interests of companies.

It is therefore argued that the precautionary principle should embrace concepts such as societal need and the acceptability of risk. In order to ensure that the least risky options are chosen, comparative assessment and the implementation of the substitution principle are seen as the way forward.

The third section discusses the possibility that a robust application of the precautionary principle might lead to future trade wars. The fourth section challenges the World Trade Organization's (WTO's) and the Commission's vision that action taken in the name of precaution should always be potentially temporary, particularly with regard to bioaccumulative and/or persistent chemicals. With reference to the Commission's Communication on the Precautionary Principle,¹ and with reference to a case study, shortfalls in the current proposed application of this principle within the EU are identified.

The conclusion is that the precautionary principle can be implemented to deliver a high level of protection, and that it is possible to balance the dual societal expectations of a clean and healthy environment and access to technologic developments.

In the EU, there are two references to precaution that are particularly important in indicating the scope of the precautionary principle. These are the Amsterdam Treaty and a ruling (relating to BSE) from the Court of Justice. The Amsterdam Treaty, which is the bedrock of the EU, amended Article 130r(2) of the Treaty of Rome, and incorporated provisions already introduced by the Maastricht Treaty of 1992. It states:

Community policy on the environment shall aim at a high level of protection taking into account the diversity of situations in the various regions of the Community; It shall be based on the precautionary principle and on the principles that preventative action should be taken, that environmental damage should as a priority be rectified at source and that the polluter should pay. (Article 174)

The Treaty explicitly refers to the precautionary principle as applying to environmental policy, but it is generally accepted as also being applicable to health policies. This is indeed confirmed by a 1998 ruling from the Court of Justice, which also suggests that within the EU, preventive measures may be taken when there is uncertainty as to whether or not a risk exists, not just the extent of that risk:

Where there is uncertainty as to the existence or extent of risks to human health, the Commission may take protective measures without having to wait until the reality and seriousness of those risks become apparent. (Court of Justice, judgement of 5 May 1998, C 180/96, Point 99)

The Commission's Communication on the Precautionary Principle, gives further preliminary guidance on how it sees the application of the precautionary principle. in the EU. However, the Commission's Communication does not have legal standing, but is an initial position that will be an important starting block in the debate both within the EU and globally. Critically, the Commission sees the application of the precautionary principle as a risk management tool, rather than an overarching principle:

. . . application of the precautionary principle is part of risk management, when scientific uncertainty precludes a full assessment of the risk and when decision-makers consider that the chosen level of environmental protection or of human, animal and plant health may be in jeopardy. (5)

The Commission therefore appears to have confused the precautionary principle with precautionary action taken under the precautionary principle.

The Communication clearly shows that the Commission considers that before the precautionary principle is applied, there has to be an evaluation of available scientific information, and an evaluation of the potential adverse effects (5.1.2). This implies that the precautionary principle will not be allowed to be a central pivot of EU environmental policy, and will relegate it to being used only in special circumstances. The view of the authors is that this is wrong; the precautionary principle should always apply, and should be used as an overarching guiding principle.

With regard to the costs of taking precautionary action, the Commission's Communication stresses the need to compare the benefits and costs of taking action and of not taking action. However, the Communication underlines that "examination of the pros and cons [of taking action] cannot be reduced to an economic cost-benefit analysis." Thus, the Commission highlights that the efficacy and public acceptability of the various options are also important. In accordance with case law, the Commission affirms that requirements linked to the protection of public health "should undoubtedly be given greater weight than economic considerations" (6.3.4). This is very much welcomed.

The need for "proportionality" is also stressed by the Commission, which means that any measures based on the precautionary principle should not be disproportionate to the desired level of protection. The Communication stresses that banning a substance will not always be the correct response as the desired level of protection may be reached via other means, such as restricting its use to certain applications, or recommendations for populations at risk.

The precautionary principle should be seen as an overarching principle rather than a risk management tool. Several components need to be embraced by this overarching principle and these are further outlined in the following points 1 to 5. First, for example, it is argued there is' a need to ensure that extremely hazardous substances do not reach the market. Second, there is a need to ensure that hazardous chemicals are used only where necessary, and where they are needed, and that only those that provide the safest options should be used.

Mechanisms are undoubtedly needed to improve the present system of chemicals management in the EU, where most chemicals have not been adequately tested, and only a relatively small number are prioritized for risk assessment. Furthermore, the risk assessment process is currently prescribed in such a way that risk reduction measures are not required unless it can be shown that the chemical is likely to be found at levels that cause harm.

Some individuals are of the opinion that risk assessment is based on firm "sound" science, while the application of the precautionary principle has little to do with sound science. However, nothing could be further from the truth, because it is "sound" science to acknowledge the limitations of our current knowledge and the uncertainties that prevail in risk assessment. It is crucial to avoid being misled by the formal framework of risk assessment into thinking that the quantification of risks is more accurate than it really is. Yet all too often the weight put upon the conclusion of a risk assessment is greater than the science would dictate, given the many assumptions and uncertainties therein. In conclusion, therefore, it is sound science to acknowledge that to more effectively prevent harm, a precautionary strategy that reduces exposures to the most hazardous substances is needed.

1. Ensure That No Chemical Lacking Hazard and Fate Data is Marketed

In order to put in place a more precautionary approach to chemicals management, it is imperative that all chemicals be adequately tested. In this way, only those that are deemed to be reasonably safe, or those that pose lesser risks, are allowed onto the market. Furthermore, to ensure that emerging concerns, such as endocrine disruption, are dealt with effectively, it needs to be recognized that more resources must be directed to developing new test methods and protocols. Older "existing" chemicals should also be tested to the best standards of the time, and the costs borne by the manufacturers. Since 1981, EU-wide legislation has meant that no new chemical can be put on the market without prior testing. However, the 100,195* older chemicals, termed "existing" chemicals, which were traded in the EU prior to 1981 have not been evaluated to the same standards. For these substances, there is a frightening lack of hazard data available, even for the 2,500 chemicals traded in quantities of 1,000 tons per year or more. For example, a recent study in the EU has shown that only 14% of these chemicals have even the basic EU set of test data available.² Furthermore, only 3% have a full data set, including long term ecotoxicity results, degradation behavior in various environmental compartments, and a complete mammalian toxicity profile. This situation is similar the world over.

Within the review of chemicals legislation under way in the EU, as of mid-2000, the Commission is pushing for manufacturers of existing chemicals, particularly those produced in high volume, to provide hazard data similar to those required for new chemicals. However, at this time it is not clear that this will become a legal guillotine for those existing chemicals lacking such data. Such a measure is a vital component of any future legislative framework based on minimum precaution. Without such a firm foundation, the management of chemicals is currently based on a "suck-it-and-see" approach, rather than precaution. Furthermore, few chemicals will ever be "spat out" by such a system because even if epidemiologic studies do reveal increased incidences of certain diseases, it is almost impossible to obtain proof of cause-and-effect for any particular chemical. This is because of the widespread exposure to a vast array of chemicals, and the potential time delays between exposures and effects.

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* It is estimated that somewhere between 20,000 and 70,000 "existing" chemicals are still on the market.

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Risk assessment of existing industrial chemicals in the EU is based on a comparison of the predicted exposure or predicted environmental concentration (PEC) with the predicted no-effect concentration (PNEC). If the PEC:PNEC ratio is less than 1, that is, the no effect concentration is not exceeded, then no risk reduction measure is required. This approach is an exercise in setting an acceptable level of exposure. This means that both man and the environment are considered to be able to tolerate, or assimilate, a certain degree of contamination.

This PEC-PNEC approach operates irrespective of the merits of the use of the substance. Yet arguably the level of protection that is acceptable will vary and will depend on the benefits that the product delivers to society. This introduces the concept of risk acceptability. For example, it can be assumed that the public would tolerate a higher level of risk from a substance used to make a false hip joint (which gave years of added mobility and where there was no suitable safer alternative) than they would from babies sucking on plastic soothers leaching phthalates' (where safer alternatives exist). Thus, if societal "need" for a substance were low, then it could arguably be justified to impose a greater margin of safety.

This concept of risk acceptability also embraces the fact that higher risks are more acceptable if the risk is borne by the person who gains the benefit. The concept of protecting the innocent victim is particularly embodied in the desire to reduce the risks for babies and children. Public communication and public participation and cultural preferences are all important considerations in evaluating the acceptability of a risk.

The framework within which risk assessment currently operates takes no account of the values of the public, and furthermore, because it is such a technical exercise it excludes the public from participating in the decision-making process.

3. Aim to Achieve a High Level of Protection

The Commission should not be constrained to take precautionary action only when there is a known threat of almost cataclysmic proportions. Indeed, the Commission's Communication recognizes that the scope of the precautionary principle extends:

. . . where preliminary objective scientific evaluation indicates that there are reasonable grounds for concern that the potentially dangerous effects on the environment, human, animal or plant health may be inconsistent with the high level or protection chosen by the EU.

This illustrates that the EU is at liberty to choose a high level of protection. Indeed, in certain circumstances, the EU can be seen to have already chosen a high level of protection. For example, in relation to the contamination of drinking water by pesticides, the permitted level was set at the limit of detection, as it was considered that pesticides should not be allowed to contaminate water sources, irrespective of their known toxicity. In the same way, high levels of protection, or "the goal of a clean environment" could be chosen with regard to man-made hazardous substances contaminating breast milk or the marine environment.

Comparative, assessment. 
The framework within which risk assessment currently operates in the EU has led environmentalists to see it as a tool that leads to business as usual. The length of time it has taken to assess the risks of just a handful of chemicals is clearly unacceptable. Similarly, the high wall that has to be climbed to almost prove that a chemical is unsafe before significant control measures are imposed does not serve the public interest. For example, even for chemicals assigned high priority by the EU, it is not possible to be confident that current risk assessment procedures, and hence regulatory actions based on a PEC:PNEC approach, will protect man and the environment. This is because there are many uncertainties about the long-term effects of exposures to chemicals and the interactive effects of exposures to cocktails of chemicals.

Underpinning the proposal that the precautionary principle should be an overarching guiding principle is the fact that risk assessment focuses more on evaluating a problem than on solving it. Comparative risk assessment should be part of this overarching principle as it provides a workable mechanism to facilitate a shift away from the use of the potentially most harmful. chemicals, and reduce the risks to human health and the environment.

Take as an example the use of flame retardants in household goods. The need to reduce the risk of fire is clearly a societal need. However, the means by which this is achieved should be subjected to comparative assessment. The option of reducing the speed at which a fire takes hold by the use of flame-retardant chemicals should be weighed against the option of using less flammable construction materials, and the mandatory use of non-chemical alternatives such as sprinkler systems, fire escapes and smoke alarms.**  If a chemical flame retardant were considered to be necessary, then comparative assessment would dictate that all the chemicals that could be used in that situation should have their benefits and risks assessed together and a comparison made, such that only the least risky, options were used.

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** In the United Kingdom in 1997 there were around 3,000 deaths per year resulting from the use of asbestos (House of Commons, FAQ, Briefing, 28 April 1997). Furthermore, in 1995 it was estimated that there were up to a quarter of a million deaths still to come (The Economist, 25 February 1995). Therefore, it could be argued that more people could have been saved if alternative methods of fire prevention and life saving options had been used instead of asbestos.

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This system of comparative assessment would ensure that where there were less risky alternatives available, these would be used. The introduction of comparative assessment would therefore lead to positive lists of substances authorized or recommended for certain specified uses.

The principle of comparative assessment has recently been included in EU legislation on biocides.³ It enables the prohibition of a biocide if there is another active substance on the market that is significantly less risky to health or to the environment. The Biocides Directive includes a number of conditions, for example, there has to be practical experience with the new alternative.

Within comparative assessment, the question is no longer "is this substance likely to cause harm to man or the environment," but is rephrased "given there is an accepted need-what is the best way (the least risky way) to serve this?"

Comparative assessment should, however, be used only to accelerate substitution for safer alternatives. The non-availability of alternatives should not delay implementing controls over a substance if the risk assessment of that substance concludes that predicted no-effect concentrations (PNECs) are likely to be exceeded.

Apart from having a place within the risk assessment of prioritized chemicals, comparative assessment, or the "substitution principle," should be included in general duties given to users or suppliers of chemicals. For example, in Swedish legislation, the Chemical Products Act gives a responsibility to companies to choose the least harmful chemical for a specific purpose and strive systematically to substitute less hazardous chemicals for hazardous ones. The widespread implementation of comparative assessment and the substitution principle would provide a means to drive down exposures to the lowest levels practicable, and would stimulate the innovation of greener, cleaner chemicals.

Comparative assessment and the substitution principle provide a dear, transparent, and rational way out of the current logjam that is apparent on both sides of the Atlantic, where many substances are under suspicion, but few are taken off the market, or even put under tighter controls.

5. Base the Quantification of Risk on Worst Case Assumptions

In order to take account of some of the uncertainties in the EU risk assessment process, certain "safety" or "assessment" factors are incorporated into the method used to derive the PECs and PNECs. These are laid down in a Technical Guidance Document. However, at many stages in the risk assessment process, there is room for expert judgement to play a part, and hence the outcome of the process is subjective.

Even a Working Paper drafted by the Commission's Industry Directorate acknowledges the uncertainties of risk assessment and underlines that conclusions may vary depending on the judgment of the person performing the exercise. It states:

. . . uncertainties during any previous step strongly compromise the reliability of the last phase, the risk characterization. The exercise does include many choices and judgements by the person performing it (e.g. selection of underlying data, models and assumptions).⁴

This highlights the need for a legal commitment that at any stage in a risk assessment process, the assumption should be that reasonable worst case scenarios are included. Currently, the technical experts of the Member States of the EU, who are charged with the responsibility of assessing the environmental risks of high-priority existing industrial chemicals, do seem to be guided to a large extent by a desire to consider the worst case scenario. However, this is not written in stone and could change. Also, of course, these experts are still constrained by the framework in which risk assessment currently operates.

In summary, risk assessment seeks to provide science-based guidance to indicate when risk reduction is needed for individual substances, in particular applications. This guidance is based on several assumptions that should always respect an overarching precautionary principle.

One of the potential problems with regard to the implementation of the precautionary principle is how non-EU governments will react if the EU progresses in seeking to deliver a higher level of environmental protection for its citizens than that operating in other World Trade Organization (WTO) member countries. The precautionary principle should not be misused to create unjustified barriers to trade, but it would clearly be unacceptable if all countries had to be bound by the lowest standards of health and environmental protection. There are cultural differences, and some nationalities may be more risk averse, while others may opt for a more crisis-management approach. It is hoped that the EU will not be thwarted from finding a safer way of doing business by the threat of transatlantic trade wars, and of being accused of disguised economic protectionism.

The Commission's Communication suggests that measures imposed under the precautionary principle should be. seen as potentially transitory. The Commission appears to have been influenced by the WTO Agreement on Sanitary and Phytosanitary Measures (SPS), which suggests that such measures should be temporary, although the precautionary principle itself is not explicitly referred to in this document. Article 5(7) of the SPS agreement states:

In cases where relevant scientific evidence is insufficient, a Member may provisionally adopt sanitary or phytosanitary measures on the basis of available pertinent information, including that from the relevant international organisations as well as from sanitary or phytosanitary measures applied by other Members. In such circumstances, Members shall seek to obtain the additional information necessary for a more objective assessment of risk and review the sanitary or phytosanitary measure accordingly within a reasonable period of time.

According to the SPS agreement, measures taken under the precautionary principle are transitional. However, they are not limited by time per se, but by the time taken to obtain additional information for a more objective assessment of the risk.

In some cases, the uncertainty about the threat of a particular substance may be due to a lack of data that can be obtained within a matter of months. In such cases, it is obviously right and proper for precautionary action to be taken temporarily. The requirement to consider new scientific information is consistent with the precautionary principle.

However, it should not be assumed that measures imposed under the precautionary principle are always potentially transitory. For example, it is the authors' view that elimination of exposures to biologically active, bioaccumulative, and/or persistent substances should be permanent, irrespective of their current known toxicities. This is because, given the diversity of species and the complexities of ecosystems, it will impossible to predict, from a few shorter-term tests on a few selected species, the effects of chronic exposure on all species. It would also be an enormous task to accurately determine the effects of concurrent exposures to the many bioaccumulating substances likely to be found as co-contaminants. Therefore, it would be both impractical and unethical to conduct the necessary number of tests to try to show beyond reasonable doubt the safety of a bioaccumulative and/or persistent compound. The possible subtle effects of a chemical on the functioning of the human central nervous system is also particularly difficult to predict from selected tests on animals with less developed brain structures. In making decisions about whether or not precautionary measures should be deemed permanent, it should be remembered that within the EU, there is already legislation in place that seeks to reduce the numbers of animals used in toxicity testing.

Apart from the difficulties regarding extrapolation of tests to other species, it should also be recognized that it is impossible to test for effects that have not yet been conceived, and of which there is therefore a total ignorance, as was the case with the stratospheric ozone depletion. Furthermore, due to the very properties of persistence and bioaccumulation, if effects due to these substances do become evident, it will be impossible to remedy the situation in the short term. This provides a compelling argument for suggesting that precautionary action on persistent⁺⁺ and/or bioaccumulative substances should be permanent.

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^{+ +} Unless durability is a desired property (as may be the case for construction materials) and losses to the environment can not occur.

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Giving industry lead times to adapt to progressive tightening of controls over persistent and bioaccumulative substances will in many cases significantly reduce costs. This means that it is important to set down the direction of future regulation, because this in itself can lead to more cost-effective solutions. There are winners and losers, and if one chemical goes, a safer alternative will be found and new jobs created.

Many of the substances that have been controlled, such as TBT (tributyltin), the PCBs (polychlorinated biphenyls), and CFCs (chlorofluorocarbons), are bioaccumulative and/or persistent. However, it took many years for the increased sensitivities of some species, or their toxic effects at low levels, or their effects in general, to become apparent. There is a need to learn from these past mistakes, and to recognize that we cannot be confident that toxicity-testing regimens will necessarily predict all effects.

A Case Study: EU Action against a Breast Milk Contaminant

The recent EU decision to regulate penta brominated diphenyl ether (penta-BDE) created a landmark precedent, and further developed the accepted method for risk assessment of chemicals in the EU. Unfortunately, however, marketing restrictions may be only temporary.

Penta-BDE is persistent and bioaccumulative, and it can disrupt the normal functioning of the thyroid hormones,^5-7 which are responsible for brain development. It is used almost exclusively as a flame retardant in polyurethane foams, especially flexible foams used in cars. It is now found in the body fat of many aquatic animals, including dolphins, seals, sea birds, and whales of the open oceans. Penta-BDE and its breakdown product, tetra-BDE, are also found in mothers' breast milk, and a Swedish study shows that the levels of poly-BDEs increased six-fold in the 25 years up to 1997.⁸

At the EU Technical Meetings in early 1999, experts of the Member States evaluated the data on penta-BDE. They agreed:

. . . it has been detected, albeit at relatively low levels, in human breast milk, the levels increasing with time. [Furthermore] with the available information it is not possible to say whether or not on a scientific basis there is a current or future risk to human health. However, it would be of concern if by the time the future information has been gathered, the analysis indicated a risk to breast feeding infants. ⁹

The technical experts therefore considered that there should be a political decision (taken by Competent Authorities [CAs]) as to whether or not there was an agreed need to reduce the risks from this substance without waiting for further research.

The need for a precautionary approach was finally agreed at the meeting of Competent Authorities in Helsinki on November 23-24, 1999. This was an important milestone, as it shows the implementation of the precautionary approach, and illustrates how the political machinery in EU is willing to respond to the knowledge that no mother on earth wants her breast milk to be contaminated with a man-made flame-retardant chemical. The current proposal is that there will be widespread marketing and use restrictions. However, in line with the Commission's paper on the precautionary principle, this action may be temporary. Thus, the minutes of the CA meeting illustrate that the conclusion was that further information was required, but that "because there was great concern on the unknown potential long-term effects on breast-fed infants, the CAs underlined the need to start Risk Reduction activities immediately." ¹⁰

In contrast, the present authors believe that marketing restrictions should be deemed permanent, and no further information required. No amount of further testing can adequately predict the subtle effects that might result from the in-utero exposure to this chemical, particularly as this substance is persistent and bioaccumulative, and is able to affect brain development in animals.¹¹

In conclusion, setting the precautionary principle as an overarching guiding principle and attempting to deliver a high level of protection is really just an admission that without some formalized framework to reduce risk, humans and wildlife may be sentenced to suboptimum health. By moving towards a system that has precaution at its heart it is possible to balance the dual societal expectations of a clean and healthy environment and access to technologic developments that increase quality of life.

1. Commission of the European Communities. Communication from the Commission on the Precautionary Principle, 02.02.2000. COM (2000)1, Brussels, Belgium, 2000.

2. Allanou R, Hansen BG, van der Bilt Y Public availability of data on EU high production volume chemicals. EUR 18996. European Chemicals Bureau, Italy, 1999.

3. Directive 98/8/EC of the European Parliament and of the Council of 16 February 1998 concerning the placing of biocidal products on the market. Official Journal of the European Communities. L123/1. 24.4.98.

4. European Commission. III.Doc97/RiMa02. Belgium, Brussels, 1997.

5. Fowles JR, Fairbrother A, Baecher SL, Kerkvliet NI. Immunologic and endocrine effects of the flame-retardant pentabromodiphenyl ether (DE-71) in C57BL/6J mice. Toxicology. 1994;86:49-61.

6. Darnerud PO, Sinjari T. Effects of polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) on thyroxine and TSH blood levels in rats and mice. In: Dioxin 1996, Organohalogen Compounds. 1996;29:316-9.

7. Olsson P-E, Borg B, Brunstrom B, Hakansson H, Klasson-Wehler E. Endocrine disrupting substances. Report 4859. ISBN 91-620-4859-7. Swedish Environmental Protection Agency, Stockholm, Sweden, 1998.

8. Meironyte D, Bergman A, Noren K, Analysis of polybrominated diphenyl ethers in human milk. In: Dioxin 1998, Organohalogen Compounds. 1998;35:387-90.

9. European Commission. Doc X1/14168/99. Brussels, Belgium, 1999.
10. European Commission. Doc ENV/800979/00. Brussels, Belgium, 2000.

11. Eriksson P, Jakobsson E, Fredriksson A. Developmental neurotoxicity of brominated flame-retardants, polybrominated dipheyl ethers and tetrabromo-bis-phenol A. In: Dioxin 1998, Organohalogen Compounds. 1998;35:375-7.