|Friday, 23 September 2011 15:18|
Elemental mercury is used as a fluid electrode in an electrolytic process (referred to as the "mercury cell" process) used for production of chlorine and sodium hydroxide (NaOH) or potassium hydroxide (KOH) from salt brine.
Relevant legislation and NGO policy work
The international community has long made efforts to reduce mercury pollution from this source: in 1990, OSPAR Decision 90/3 of 14 June recommended reducing chlor-alkali mercury emissions to 2 grams of mercury per tonne of Cl2 capacity and phasing out the activities of existing mercury-cell installations in chlor-alkali production plants as soon as possible, with the aim of achieving the objective of their total closure by 2010 at the latest. In order to tackle other mercury problems in a more holistic way the EU adopted in 2005, a Community Strategy on Mercury. The Commission strategy proposed a series of actions to cut EU and global emissions and uses of mercury, including banning EU mercury exports by 2011. It also addressed safe storage of mercury removed from MCCAPs, which have been decommissioned by the EU chlor-alkali industry.
Even though the Strategy makes reference to the chlor-alkali industry, the Integrated Pollution Prevention and Control (IPPC) Directive (96/61/EC) was until recently the only legally binding instrument applicable to the chlor-alkali sector, supported by some broader legislation, such as the Water Framework Directive. Before integrated pollution permits were required, Directive 84/360/EEC regulating mercury emissions into the atmosphere was applied to the chlor-alkali industry, until it was superseded by the IPPC Directive, which required installations to seek permits based on the best available techniques (BAT). The benchmarks or criteria on which BAT relies are described in the BAT Reference Documents (BREFs). The first chlor-alkali BREF document was published at EU level in December 2001. According to the chlor-alkali BREF, the membrane (mercury free) process, and not the mercury-cell process, is regarded as BAT for the chlor-alkali industry. In addition, the Directive states that existing installations - installations in operation before October 1999 - should operate in accordance with the requirements of the Directive by 30 October 2007. However, when determining the permit requirements based on BAT for a specific installation, the competent authority is permitted to take into account the technical characteristics of the installation concerned, its geographical location and local environmental conditions. Therefore, it is the local competent authority that decides on the specific permit requirements, and the system has an inherent flexibility as to how these requirements may be (mis)interpreted, depending on the specific case.
The IPPC Directive has been transposed into national legislation in all Member States.
However, the transposition, let alone the implementation, of the Directive differ significantly among the various European Member States.
In 2010- the IPPC was replaced by the Industrial Emissions Directive (IED),which has entered into force on 6 January 2011 and has to be transposed into national legislation by Member States by 7 January 2013. Although the principle is the same as for IPPC, the role of the BREFs has now been strengthened, providing more opportunities to the legislator to question why mercury process may still be permitted in the sector. The real effects of the directive in the sector are expected to be seen however only in 2016-2017, so around 4 years after the revision of the chlor-alkali BREF. The revision of the BREF has started in 2010 and is expected to be finalised in 2012. In terms of quality standards in different environmental media, at EU level, the relevant legislation addressing ambient air quality standards for certain substances including mercury, is Directive 2004/107/EC of the European Parliament and of the Council relating to arsenic, cadmium, mercury, nickel and polycyclic aromatic hydrocarbons in ambient air (the 4th daughter directive of Council Directive 96/62 on ambient air quality assessment and management). Mercury in ambient air is not regulated via a target value; instead, it is measured at background sampling points with a spatial resolution of 100,000 km2 in order to provide information on geographical variation and long-term trends. Monitoring of particulate and gaseous divalent mercury is also recommended.
In addition, with reference to water, Council Directive 82/176/EEC of 22 March 1982 on limit values and quality objectives for mercury discharges by the chlor-alkali electrolysis industry (OJ L 81, 27.03.1982, p. 29-34) applies, but will be repealed with effect from 22 December 2012. The newly adopted10 EU directive on Environmental Quality Standards (EQS) in the field of water policy will then apply.11 Transitional measures of monitoring for the Member States according to the Water Framework Directive (2000/60/EC) are foreseen. Member States shall apply the EQS laid down in Part A of Annex I to this Directive in bodies of surface water. In annex I, Part A, the following Environmental Quality Standards (EQS) apply for mercury:
i This parameter is the EQS expressed as an annual average value (AA-EQS). Unless otherwise specified, it applies to the total concentration of all isomers.
ii Inland surface waters encompass rivers and lakes and related artificial or heavily modified water bodies.
iii This parameter is the Environmental Quality Standard expressed as a maximum allowable concentration (MAC-EQS). Where the MAC-EQS are marked as "not applicable", the AA-EQS values are considered protective against short-term pollution peaks in continuous discharges since they are significantly lower than the values derived on the basis of acute toxicity.
viii If Member States do not apply EQS for biota they shall introduce stricter EQS for water in order to achieve the same level of protection as the EQS for biota set out in Article 3(2). They shall notify the Commission and other Member States, through the Committee referred to in Article 21 of Directive 2000/60/EC, of the reasons and basis for using this approach, the alternative EQS for water established, including the data and the methodology by which they were derived, and the categories of surface water to which they would apply.
Member States may opt to apply EQS for sediment and/or biota instead of those laid down in Part A of Annex I in certain categories of surface water. Member States that apply this option shall: apply, for mercury and its compounds, […], these EQS being for prey tissue (wet weight), choosing the most appropriate indicator from among fish, molluscs, crustaceans and other biota.
Another piece of legislation relevant to the chlor-alkali sector is the recently adopted EU Regulation on an EU export ban and safe storage of mercury (EC/1102/2008); the export of metallic mercury is banned after 15 March 2011, and mercury from decommissioned chlor-alkali plants shall be safely stored.
Finally, with respect to reporting obligations the European Pollutant Emission Register (EPER), the first European-wide register of industrial emissions into air and water, was established in 2000. The European Pollutant Release and Transfer Register (E-PRTR) adopted in 2006, has succeeded the EPER. It is intended to fully implement the obligations of the UN-ECE PRTR Protocol, which was signed in May 2003 by 36 countries and the European Community. The obligations under the E-PRTR Regulation extend beyond the scope of EPER mainly in terms of more facilities included, more substances to report, additional coverage of releases to land, off-site transfers of waste and releases from diffuse sources, public participation and annual instead of triennial reporting. The first reporting year under the E-PRTR will be the year 2007 and respective information will have to be reported by Member States in June 2009. The second reporting round (2008 data) will be initiated in March 2010 and become publicly available in April 2010. E-PRTR will also require reporting of emissions of Hg to land when released above the threshold of 1kg/year.
According to the industry association Euro Chlor, the European chlor-alkali industry has agreed to convert or close down most of the mercury-cell facilities by 2020, which the industry has described as the end of the normal economic lifetime of most EU MCCAPs; or in other words, simply as long as it believes it can keep its outdated MCCAPs operating profitably. Industry has more recently explained that ‘the long time-frame is essential to allow chlor-alkali producers to absorb the estimated 3.000 million Euro investment required to effect the phase-out without damaging the industry's competitive position on global markets.’
The European Environmental Bureau through its Zero Mercury Campaign focused on the mercury use in the chlor-alkali sector and more specifically organised on the ground campaigns in five EU countries in view of:
The campaign took place from 2006 - 2010, in Italy,Spain, theCzech republic,Germany, and Francefrom NGOs, members of the EEB/ZMWG - Legambiente, Ecologistas en Acción, Arnika, DNR, and France Nature Environnement (FNE), respectively.
For more information on these projects, their results and respective publications please visit our specialised Project's page or the country's page.
Important work is currently being carried out under the UNEP Global Mercury Partnership on Reducing Mercury in the Chlor-alkali sector. A global inventory of plants around the world still using mercury cell process is available.
In Indiathere is a voluntary agreement between government and industry, initiated by the (Indian) Central Pollution Control Board, according to which the phase-out of Indian MCCAPs will occur by 2012. InJapan, the electrolytic cell technique has been largely phased out since the mid 1980s.
In the US relevant specific regulations can be found at http://www.epa.gov/hg/regs.htm#regs,
The ZMWG has been following this issue closely and has been giving respective feedback at the global mercury negotiations. See also the ZMWG fact sheet Chlor-alkali (Jan 2011)