|Paints and varnishes|
Phenyl mercuric acetate (PMA) and similar mercury compounds have been widely used as water-based paint additives, and may still be used in some countries. These compounds were used as “in-can” preservatives to extend the shelf life by controlling bacterial fermentation in the can (biocides), as well as to retard fungus attacks on painted surfaces under damp conditions (fungicides).
Inorganic mercury compounds of very low solubility have also been used as additives in marine coatings and paints to impede bacteria formation and to hinder the development of marine organisms. This use is believed to have been largely discontinued by the mid-1970s (US DOC, as cited in NJ MTF, 2002).
Relevant legislation and NGO policy work
In the EU
The European Union directive 76/769/EEU restricts the marketing and use of certain dangerous substances and preparations, and includes a prohibition of the use of mercury substances in marine anti-fouling paints, wood preservatives, among others.
In theUSAthe use of mercury biocides in paint officially ended in 1991. Prior to that, mercury compounds were used in 25 to 30% of all interior latex paints (it was not used in oil-based paints), and in 20 to 35% of outdoor latex paints (Heier, 1990). An estimated 227 metric tons per year of PMA and other mercury compounds were used in paints in the USA between the mid 1960s and 1991 (NJ MTF, 2002). It would be interesting to carry out an inventory of the obsolete stocks of these paints that could still be stored in households.
Information is provided at http://www.epa.gov/hg/consumer.htm#bat bat and at http://www.newmoa.org/prevention/mercury/modelleg.cfm
In a reported incident of mercury poisoning in 1989 in theUS, the walls were painted with latex paint containing 930-955 ppm mercury (MMWR, 1990).
The use of mercury in paints has now been substantially reduced or eliminated in a large number of countries. Among others,Mauritius,Cameroon,Costa Rica,Japan,Norway, theUSAandSwitzerlandhave all discontinued this use (UNEP, 2002). Some paint industries inThailandhave no mercury in their processes or paints since 1991, and are certified as “green label.”
During the Global Mercury Assessment (UNEP, 2002) Thailand reported that less than 25% of the paint factories in Thailand still use mercury compounds as additives, and in quantities of not more than 0.5% of total weight. In Costa Rica, the regulation on the content of lead and mercury in paints sets a maximum limit of 50 ppm (0.005 %) mercury. Australia, Ghana, Guinea, India, Ireland, Samoa and Trinidad and Tobago (mostly discontinued now) have also indicated recent or continued use of mercury in paints (UNEP, 2002),