Composition

One of 5 stable HCH isomers in technical HCH

Uses

Alpha-HCH by itself is neither intentionally produced nor placed on the market but produced as the main constituent of technical HCH which is used as organochlorine insecticide or chemical intermediate to manufacture enriched gamma-HCH (Lindane).

Releases

Historically, alpha-HCH was released during the manufacture of technical HCH and its use as a pesticide. Li and Macdonald (2005) estimated the global usage of alpha-HCH (based on data on technical HCH) at 6 millions tons, with 4.3 millions tons emitted into the atmosphere. Releases of alpha-HCH into the environment are also possible from hazardous waste sites (USEPA, 2006), stockpiles and residues of Lindane production, which are not always controlled or maintained safely (IHPA, 2006). Also, contaminated sites (e.g. from former production plants) may contribute to the environmental burden of alpha-HCH (Concha-Grana et al., 2006). Though no quantitative estimates of these releases exist, the amounts of HCH residuals in the form of by-products from Lindane production are assumed to range between 1.6 - 1.9 to 4.8 million tons.

Fate

Degradation is very slow especially at lower temperatures. Half-lives for alpha-HCH in Arctic lakes were up to 1.4 years, whereas in the Eastern Arctic Ocean enantioselective degradation resulted in a range of approximately 5 to 17 years. High levels are found in Arctic biota because of the bioaccumulation potential of alpha-HCH (as a product of bioconcentration and biomagnification) and the historically particularly efficient deposition processes of this substance in the Arctic waters. The efficient accumulation is an effect of the combination of the physico-chemical properties of alpha-HCH and the low temperature in the Arctic. In other words, alpha-HCH effectively accumulates in the Arctic ecosystem as a whole.

Effects

Alpha-HCH has been shown to be neurotoxic, hepatotoxic, and to cause immunosuppressive effects and cancer in laboratory animals. The International Agency for Research on Cancer (IARC) has classified alpha-HCH in group 2B, possibly carcinogenic to humans. Several epidemiological studies indicate that alpha-HCH might play a role in human breast cancer. Alpha-HCH is a known tumour promoting agent. Alpha-HCH may adversely affect human health in contaminated areas as well as in Arctic regions. Based on the available toxicity data of alpha-HCH, it can be concluded that current concentrations of alpha-HCH in food and human breast milk are a matter of concern. The estimated daily intake of alpha-HCH of Arctic indigenous people exceeds safe intake reference values, even though estimation is very conservative. Compared with a general accepted risk of one case per million, this risk seems unacceptably high. Nevertheless it should be emphasized that traditional foods have unique social, cultural, spiritual and economic value and therefore it is strongly recommended to avoid alpha-HCH levels of concern. Human exposure to alpha-HCH results mostly from ingestion of contaminated plants, animals and animal products. Monitoring data from a wide range of biota including humans suggest that significant uptake from the environment occurs, which demonstrates the bioavailability of alpha-HCH. Monitoring data show its ubiquitous distribution in all environmental media

Exposure

Human exposure to alpha-HCH results mostly from ingestion of contaminated plants, animals and animal products. Monitoring data from a wide range of biota including humans suggest that significant uptake from the environment occurs, which demonstrates the bioavailability of alpha-HCH. Monitoring data show its ubiquitous distribution in all environmental media

Status

Technical HCH is listed in Annex II of the 1998 Aarhus Protocol on Persistent Organic Pollutants (POPs) under the Convention on Long-Range Transboundary Air Pollution which restricted alpha-HCH use to an intermediate in chemical manufacturing only. HCH (mixed isomers) is subject to the PIC Procedure of the Rotterdam Convention and is listed in Annex III of the Convention. In the European Union, the production and use of technical HCH as an intermediate in chemical manufacturing will be phased out by the end of 2007 at the latest (Regulation (EC) No 850/2004). HCHs are also among the priority substances (Decision No 2455/2001/EC) of the adopted EU Water Framework Directive 2000/60/EC. Hexachlorocyclohexane isomers, including the alpha-isomer, are on the List of Chemicals for Priority Action under the OSPAR Commission for the Protection of the Marine Environment of the Northeast Atlantic.

Alternatives

Will be discussed together with Lindane in Annex F evaluation if Alpha HCH advances.

Composition

One of 5 stable HCH isomers in technical HCH at levels of 5 – 14%.

Uses

Beta-HCH by itself is neither intentionally produced nor placed on the market. It is produced as constituent of technical HCH used as organochlorine insecticide or chemical intermediate to manufacture enriched HCH (lindane). Currently no production data on technical HCH have been reported, whereas manufacture of lindane still takes place (IHPA, 2006).

Releases

Around 10 million tons of technical HCH were released to the environment between 1948 and 1997 (Li et al. 1999). According to Li and Macdonald (2005) global usage of technical HCH was dominated by 10 countries headed by China, which consumed almost half of the total global quantity. The other countries were (in order of decreasing usage): Former Soviet Union, India, France, Egypt, Japan, United States, East Germany, Spain and Mexico. Historically beta-HCH was released during the manufacture of technical HCH and its use as a pesticide. Li et al. (2003) estimated global emissions of beta-HCH from the usage of technical HCH between 1945 and 2000 at 850 000 tons, of which 230 000 tons were emitted into the atmosphere over the same period. As a result of the ban on technical HCH in northern countries, global emissions of beta-HCH have undergone a “southward tilt” (Li et al., 2003). Releases of beta-HCH into the environment are also possible from hazardous waste sites (USEPA, 2006), stockpiles and residues of lindane production, which are not always controlled or maintained safely (IHPA, 2006). Also, contaminated sites (e.g. from former production plants) may contribute to the environmental burden of beta-HCH (Concha-Grana et al., 2006).

Fate

Abiotic degradation processes do not play an important role in the fate of beta-HCH in the environment. Thus photolysis and hydrolysis are not significant. Under favourable conditions, beta-HCH is susceptible to biodegradation. However compared to the gamma- and alpha-HCH it is the most recalcitrant isomer. Laboratory and field data including a long-term soil study suggest that beta-HCH is persistent in soil, especially under low temperatures. It is mainly associated with particles and has a low leaching potential. The physico-chemical properties of beta-HCH allow the dispersal of the substance from its sources to the Arctic mainly by long-range environmental transport via ocean currents. Beta-HCH has been detected in the Arctic Ocean and is present in marine, terrestrial species, and humans.

Effects

Beta-HCH is acutely toxic to aquatic organisms and shows estrogenic effects in fish. Reduced fitness of offspring in birds as well as reduced retinol concentrations in polar bears is associated with beta-HCH and HCHs levels. Toxicological studies with beta-HCH have demonstrated neurotoxicity and hepatotoxicity. Also reproductive and immunosuppressive effects and effects on fertility were seen in laboratory animals. Beta-HCH has been classified in group 2B as possibly carcinogenic to humans by the International Agency on Research and Cancer (IARC). Several epidemiological studies indicate that beta-HCH might play a role in human breast cancer.

Exposure

Beta-HCH exposure levels in local areas have declined after worldwide prohibitions and restrictions. However regions with recent exposure and/or high pollution can still show elevated levels. A special concern also arises from exposure of hazardous waste sites and dumping grounds from disposed beta-HCH residues from lindane production. Due to its persistence beta-HCH can still be detected at low background levels in all environmental media except in regions with recent usage and/or high pollution. Data from the abiotic environment in the Arctic are scarce partly due to low levels compared with the other HCH isomers. In contrast to this fact fairly high concentrations in Arctic biota including marine mammals and birds were detected with increasing levels. Beta-HCH is present in terrestrial and aquatic food chain. Beta-HCH may bioaccumulate and biomagnify in biota and Arctic food webs, especially in upper trophic levels. In humans accumulation in fat tissue and high concentrations in blood and in breast milk may occur. Beta-HCH transfers from mothers to embryos and nursing infants. Human exposure to beta-HCH results mostly from ingestion of contaminated plants, animals and animal products. High exposure is expected in contaminated areas due to extensive use, former production, disposal sites and stockpiles. Based on the hazard profile and the exposure levels in the environment including the food chain, it can be concluded that beta-HCH may adversely affect wildlife and human health in contaminated regions. Arctic public health authorities believe the significant social, cultural and economic benefits of traditional foods outweigh the risks of contaminants such as HCH at present but give another reason for the quick control and elimination of all HCH isomers from traditional foods. However based on levels found in the Arctic region, it can be also concluded that beta-HCH can lead to significant adverse human and environmental effects as a result of its long-range environmental transport.

Status

Technical HCH is listed in Annex II of the 1998 Aarhus Protocol on Persistent Organic Pollutants (POPs) under the Convention on Long-Range Transboundary Air Pollution which restricted alpha-HCH use to an intermediate in chemical manufacturing only. HCH (mixed isomers) is subject to the PIC Procedure of the Rotterdam Convention and is listed in Annex III of the Convention. Canada, Mexico, and the United States signed the North American Regional Action Plan (NARAP) on Lindane and Other Hexachlorocyclohexane Isomers in 2006 with the goal of reducing the risks associated with the exposure of humans and the environment to lindane and other HCH isomers. In the European Union the production and use of technical HCH as an intermediate in chemical manufacturing will be phased out by the end of 2007 at the latest (Regulation (EC) No 850/2004). HCHs are also one of the priority substances (Decision No 2455/2001/EC) of the adopted EU Water Framework Directive 2000/60/EC. Hexachlorocyclohexane isomers, including the beta-isomer, are on the List of Chemicals for Priority Action under the OSPAR Commission for the Protection of the Marine Environment of the Northeast Atlantic.

Alternatives

Will be discussed together with Lindane in Annex F evaluation if Beta HCH advances.

Composition

Synthetic chlorinated organic compound also known as Kepone, GC-1189, Merex, ENT 16391, and Curlone. Chlordecone is closely related chemically to mirex, a pesticide which is already listed under the Stockholm Convention. The chemical structure of chlordecone differs from mirex in that the oxygen of the keto group in chlordecone is replaced by two chlorine atoms in mirex.

Uses

Based on the available information, Chlordecone is not anymore produced or used. Chlordecone has been used in various parts of the world for the control of a wide range of pests. In particular, Chlordecone has been used extensively in the tropics for the control of banana root borer. It has been used as a fly larvicide, as a fungicide against apple scab and powdery mildew and to control the Colorado potato beetle, rust mite on non-bearing citrus, and potato and tobacco wireworm on gladioli and other plants. Chlordecone has also been used in household products such as ant and roach traps. Chlordecone was also found to be present in technical grade mirex.

Releases

Given the specific pesticidal uses of Chlordecone, it can be expected that all amounts manufactured are ultimately released to the environment. The use of Chlordecone as a pesticide in Martinique and Guadeloupe until 1993, resulted in severe contamination of soil and surface water, which are being monitored at present. (Bocquene & Franco, 2005, Beaugendre, 2005). Major releases of Chlordecone occurred to the air, surface waters, and soil surrounding a major American manufacturing site in Hopewell, Virginia. Releases from this plant ultimately contaminated the water, sediment, and biota of the James River, a tributary to the Chesapeake Bay (Quoted from US ATSDR, 1995).

Fate

Chlordecone is not expected to hydrolyse or biodegrade in aquatic environments, nor in soil. Direct photodegradation is not significant. Therefore, Chlordecone is considered to be highly persistent in the environment. Chlordecone is considered to have a high potential for bioaccumulation and biomagnification. Due to lack of monitoring data on chlordecone, the assessment of the potential for long-range transport of chlordecone was based on physico-chemical properties and application of long range transport models.

Effects

Chlordecone is readily absorbed into the body and accumulates following prolonged exposure. The pesticide is both acutely and chronically toxic, producing neurotoxicity, immunotoxicity, reproductive, musculoskeletal and liver toxicity at doses between 1 - 10 mg/kg bw/day in experimental animal studies. Liver cancer was induced in rats at a dose of 1 mg/kg body weight per day, and reproductive effects are seen at similar dose levels. The International Agency for Research on Cancer has classified chlordecone as a possible human carcinogen (IARC group 2B). Moreover, chlordecone is very toxic to aquatic organisms, with the most sensitive group being the invertebrates.

Exposure

The available information regarding environmental concentrations of Chlordecone is very limited and includes only areas in the vicinity of production (US) or use (Martinique). Recent monitoring data from the United States demonstrate the persistence of Chlordecone, known as Kepone in the United States. In Martinique, the widespread use of Chlordecone until 1993 has resulted in contamination of soils and surface water in most of the island (Bocquené & Franco, 2005). \

Status

Chlordecone is listed in Annex I of the Protocol to the Convention on Long-Range Transboundary Air Pollution (CLRTAP) on Persistent Organic Pollutants. The provisions of the Protocol oblige Parties to phase out all production and uses of Chlordecone. Chlordecone is also included in the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR Convention) as a substance of possible concern^[1]. Under the Convention on the Protection of the Marine Environment of the Baltic Sea Area (HELCOM Convention[2]) Chlordecone is listed as selected substances for immediate priority action (Recommendation 19/5, Attachment, Appendix 3) and is scheduled for elimination (Annex I, part 2). HELCOM aims to move towards the target of the cessation of discharges, emissions and losses of hazardous substances by the year 2020. Under the Basel Convention off-specification or out-dated pesticides, without specific mention of Chlordecone, are classified as hazardous in Annex VIII. Chlordecone is currently not listed in the Rotterdam Convention on the Prior Informed Consent Procedure for certain hazardous Chemicals and Pesticides in international trade. Thailand has submitted a notification of Final Regulatory Actions for Banned or Severely Restricted Chemicals that has been verified to meet the requirements of Annex I of the Rotterdam Convention.

Alternatives

A variety of chemical alternatives have been utilised including ethoprop, oxamyl, cyfluthrin, imidacloprid, azadirachtin, bifenthrin, boric acid, carbaryl, capsaicin, cypermethrin, cyfluthrin, deltamethrin, diazinon, dichlorvos, esfenvalerate, imidacloprid, lamda-cyhalothrin, malathion, permethrin, piperonyl butoxide, pyrethrins, pyriproxyfen, resmethrin, s-bioallerthrin, tetramethrin, aldicarb, isophenphos, phenamiphos, cadusaphos, terbuphos. Alternatives to chlordecone also include non-chemical agroecological methods, such as preventative pest management through appropriate fertility and field sanitation practices that reduce pest pressure; the use and habitat enhancement of natural enemies; microbial preparations such as Bacillus thuringiensis; cultural practices such as crop rotation, intercropping, and trap cropping; barrier methods, such as screens, and bagging of fruit; use of traps such as pheremone and light traps to attract and kill insects. These and other agroecological methods are being extensively and successfully practised in many countries, eliminating the need for Chlordecone or other chemical interventions.

Composition

There are four relevant forms of endosulfan: alpha endosulfan, beta endosulfan, endosulfan sulphate, and technical endosulfan which is a 2:1 to 7:3 mixture of the alpha and beta isomers.

Uses

Insecticide for control of aphids, thrips, beetles, foliar feeding larvae, mites, borers, cutworms, bollworms, whiteflies, and leafhoppers. Used on cotton, tobacco, cantaloupe, tomatoes, squash, eggplant, sweet potato, broccoli, pears, pumpkins, corn, cereals, oilseeds, potatoes, tea, coffee, cacao, soybean, and other vegetables. Historically used to control termites and tsetse fly. Used in some countries in the past as a wood preservative.

Releases

The vast majority of endosulfan is used as active ingredient of plant protection products. That means it is deliberately spread over large soil or plant areas. Worldwide production estimated at 10,000 metric tonnes, however, current global production is likely to be significantly higher as use remains widespread. Recently the GAPS study, a global monitoring project on POPs, revealed that endosulfan “showed highest values of all the organochlorine pesticides (OCPs) investigated, in the range of tens to hundreds of pg/m³, with a geometric mean of 58”. Endosulfan was also among those organochlorine chemicals which were present in highest concentrations worldwide in samples from tree bark lipids. Unlike for more volatile compounds no significant correlation with geographical latitude was found. The authors concluded that these compounds are not as effectively distilled and tend to remain near the original region of use.

Fate

In the environment, endosulfan is oxidized in plants and in soils to form primarily endosulfan sulfate and endosulfan-diol. Formation of endosulfan sulfate is mediated essentially by micro-organisms, while endosulfan-diol was found to be the major hydrolysis product. Endosulfan was measured repeatedly in Arctic seawater during the 1990s. Mean concentrations were similar to those of chlordane. Concentrations of endosulfan from Arctic air monitoring stations increased from early to mid-1993 and remained at that level through the end of 1997. Reported values for measured bio-concentration factors of endosulfan in various aqueous organisms cover a wide range from 100 in oysters to 11,000 in whole fish. Half-lives in acidic to neutral soils range from one to two months for α-endosulfan and from three to nine months for β-endosulfan under aerobic condition. The estimated half-lives for the combined toxic residues (endosulfan+ endosulfan sulfate) ranged from roughly 9 months to 6 years. Anaerobic conditions may considerably extend half-lives in soils.

Effects

The oxidised metabolite, endosulfan sulfate, shows an acute toxicity similar to that of the parent compound.  In contrast, endosulfan-diol, which is another metabolite of endosulfan, is found substantially less toxic to fish by about three orders of magnitude. Recent literature has indicated the potential for endosulfan to cause some endocrine disruption in both terrestrial and aquatic species. Effects observed were impaired development in amphibians, reduced cortisol secretion in fish, impaired development of the genital tract in birds and hormone levels, testicular atrophy and reduced sperm production in mammals. Excessive and improper application and handling of endosulfan have been linked to congenital physical disorders, mental retardations and deaths in farm workers and villagers in developing countries in Africa, southern Asia and Latin America. Endosulfan was found among the most frequently reported intoxication incidents, adding unintentionally further evidence to its high toxicity for humans. In laboratory animals, endosulfan produces neurotoxicity effects, which are believed to result from over-stimulation of the central nervous system.  It can also cause haematological effects and nephrotoxicity.  The α-isomer was generally found more toxic than the β-isomer.

Exposure

Endosulfan was detected in adipose tissue and blood of polar bears from Svalbard. Endosulfan has also been detected in blubber of minke whale and in liver of northern fulmar. Endosulfan was detected in all lake trout examined from isolated Ontario (Canada) and New Brunswick lakes.

Status

Endosulfan has been included in the OSPAR List of Chemicals for Priority Action (update 2002). Endosulfan is on the list of priority substances agreed by the Third North Sea Conference (Annex 1A to the Hague Declaration). The second meeting of the Chemical Review Committee agreed to recommend to the Conference of the Parties that endosulfan should be listed in Annex III of the Rotterdam Convention and developed a rationale setting out how the criteria in Annex II had been met.

Alternatives

Will be discussed in Annex F evaluation if Endosulfan advances.

Composition

Hexabromobiphenyl belongs to a wider group of polybrominated biphenyls (PBBs). The term “polybrominated biphenyls” or “polybromobiphenyls” refers to a group of brominated hydrocarbons formed by substituting hydrogen with bromine in biphenyl. The hexabromo congeners exist as 42 possible isomeric forms. Trade names include FireMaster BP-6 and FireMaster FF-1. The commercial production of PBBs began in 1970. Approximately 6 million kg of PBBs were produced in the United States from 1970 to 1976. Production and use of hexabromobiphenyl has ceased in most, if not all, countries. However, it is possible that hexabromobiphenyl is still being produced in some developing countries or in countries with economies in transition.

Uses

Hexabromobiphenyl has been used as a fire retardant in acrylonitrile-butadiene-styrene (ABS) thermoplastics for constructing business, machine housings and in industrial and electrical products and in polyurethane foam for auto upholstery. A considerable part of the substance produced will probably reach the environment sooner or later because of the high stability of these compounds.

Releases

Data for loss into the environment during normal production are published only for the United States. In 1973, an accidental release of PBBs occurred in Michigan (referred to as the "Michigan disaster" in EHC 152), when two products manufactured by the Michigan Chemical Company were inadvertently confused and 250-500 kg (Di Carlo et. al., 1978) of FireMaster^(R), instead of NutriMaster^(R), a magnesium oxide-based cattle feed supplement, were added to animal feed and distributed to farms within the state. This accidental mix up resulted in widespread contamination by PBBs. Approximately 5350 tonnes of hexabromobiphenyl were used in commercial and consumer products in the United States, most in the production of plastic products with an estimated use life of 5–10 years (Neufeld et. al., 1977). Since the cessation of production, all of these products, such as TV cabinet and business machine housings, are expected to have been disposed of by land filling or incineration (Neufeld et al., 1977)

Fate

According to available data, hexabromobiphenyl can be considered to be highly persistent in the environment. There is evidence of low or no degradation in water, soil and sediment, in the laboratory as well as in the field. Hexabromobiphenyl is less volatile than many of the currently listed POP substances. However, extensive data on monitoring shows that it is found throughout the Arctic wildlife, demonstrating that it does have a high potential for long range environmental transport. With measured weight-based BCF values in the range 4,700-18,100 and biomagnification factors in the aquatic food chain exceeding 100, hexabromobiphenyl is considered to be highly bioaccumulative and to have a high potential for biomagnification. These properties are demonstrated by several authors to be comparable to those of hexachlorobiphenyl (a PCB compound), for which the bioaccumulative properties are well documented.

Effects

Hexabromobiphenyl is readily absorbed into the body and accumulates following prolonged exposure. Although the acute toxicity of hexabromobiphenyl is low, a number of chronic toxic effects including hepatotoxicity have been observed in experimental animals at doses around 1 mg/kg bw/day following long-term exposure, and effects are seen in the rat thyroid at doses as low as 0.05 mg/kg bw/day. The International Agency for Research on Cancer has classified hexabromobiphenyl as a possible human carcinogen (IARC group 2B). The PBBs are endocrine disrupting chemicals, and effects are seen on reproductive capacity in rats, mink and monkeys.  There is epidemiological evidence of hypothyroidism in workers exposed to polybrominated biphenyls and of increased incidence of breast cancer in exposed women. Data on toxicity to other species than laboratory mammals is scarce but suggests the environmental toxicity of hexabromobiphenyl is comparable to that of hexachlorobiphenyl.

Exposure

Recent monitoring data in soil, water and sediments for PBBs are limited. Historical monitoring data from the United States indicate that environmental PBB concentrations are confined to areas near former manufacturing facilities and regions of Michigan affected by the farm accident of the early 1970's (see Section 2.2.3) (US ATSDR, 2004). The only available data for environmental concentrations of PBBs in areas outside the vicinity of former production sites are those from sediment samples from Greenland (Vorkamp et. al., 2004), where PBBs (including PBB 153) were not detected in any sample (the limits of detection/quantification are, however, not well defined in the paper). The US ATSDR (2004), considers the current human exposure to PBBs to be very low, because PBBs are no longer produced or used. Thus, the general population exposure to PBBs will only be from historical releases. For people residing in the lower peninsula of Michigan, especially in the immediate vicinity of the PBB contaminated areas of this region, exposure to PBBs may still be occurring today. However, environmental levels have decreased since the 1970s and current exposure, if any, will be at low levels. For other regions of the United States, the levels of exposure will either be very low or none (Quoted from US ATSDR, 2004)/ In Arctic and North Atlantic regions, where the traditional diet includes top predators (e. g. seal in Greenland and pilot whale in the Faroe Islands), exposure has not ceased. Especially the level of PBBs in pilot whale blubber of up to 17 µg/kg lipid indicate the presence of hexabromobiphenyl in food. Pilot whale blubber is consumed as a delicacy in the Faroe Islands.

Status

Hexabromobiphenyl is listed in Annex A of the Protocol to the Convention on Long-range Transboundary Air Pollution (CLRTAP) on Persistent Organic Pollutants. The provisions of the Protocol oblige Parties (currently 25) to phase out all production and uses of hexabromobiphenyl. Hexabromobiphenyl, together with other PBBs, is also included in the UNEP/FAO Rotterdam Convention on the Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade. Under the Helsinki Convention on the Protection of the Marine Environment of the Baltic Sea Area (HELCOM^[3]) hexabromobiphenyl is listed as a selected substance for immediate priority action (Recommendation 19/5, Attachment, Appendix 3) and is scheduled for elimination (Annex I, part 2). HELCOM aims to move towards the target of the cessation of discharges, emissions and losses of hazardous substances by the year 2020. Under the Basel Convention, PBBs are classified as hazardous in Annex VIII without further specification. SAICM does not specifically address Hexabromobiphenyl but includes POPs as a class of chemicals that might be prioritized for assessment and related studies.

Alternatives

The hexabromobiphenyl risk profile describes three principal commercial products that contained hexabromobiphenyl in the USA and Canada: 1) acrylonitrile-butadiene-styrene (ABS) thermoplastics
used for business machine housings and electrical products such as radio and TV; 2) fire retardant in cable coatings and lacquers, and 3) fire retardant in polyurethane foam for auto upholstery. A number of reports on risk assessment of alternative substances and processes are available. The OSPAR priority substances Series (OSPAR, 2001) provides summary information on alternatives for brominated flame retardants. The Danish Environmental Protection Agency has described alternative halogen-free flame retardants for a variety of uses including epoxy, phenolic resins, rigid and soft polyurethane foam, textiles, and a variety of plastics including ABS (Danish EPA, 1999). Both drop-in chemical substitutes and alternative materials are listed. US EPA has described process alternatives and chemical substitutes for polyurethane foam (USEPA, 2005). The German Federal Ministry of Environment has reported on alternatives for flame retardants used in electronics, upholstery, and other sectors (BMU, 2000). As brominated flame retardants only account for about 15% of the global flame retardant consumption, principally a large number of compounds may be considered as alternatives (OSPAR, 2001). Substitution can take place at three levels: 1) brominated flame retardants can in some applications be replaced by another flame retardant without changing the base polymer; (major group of substitutes); 2) the plastic material, i.e. the base polymer containing flame retardants and other additives, can be replaced by another plastic material; (e.g. polysulfone, polyaryletherketone and polyethersulfone) 3) a different product can replace the product, e.g. the plastic material is replaced by another material (e.g. wool), or the function can be fulfilled by the use of a totally different solution.

Composition

Lindane is the common name for the gamma isomer of 1,2,3,4,5,6-hexachlorocyclohexane (HCH). It is one of 5 stable HCH isomers in technical HCH. The gamma isomer is the only isomer showing strong insecticidal properties. The production of lindane is inefficient as for each ton of Lindane (gamma isomer) obtained, approximately 6-10 tons of other isomers are also obtained (IHPA, 2006).

Uses

Lindane has been used as a broad-spectrum insecticide for seed and soil treatment, foliar applications, tree and wood treatment and against ectoparasites in both veterinary and human applications. In the last years the production of lindane has rapidly decreased and it appears that only Romania and India are current producing countries. If the estimate of global usage of lindane of 600,000 tons between 1950 and 2000 is accurate, the total amount of possible residuals (if it is assumed that a mean value of 8 tons of waste isomers are obtained per ton of lindane produced) amounts to possibly 4.8 million tons of HCH residuals that could be present worldwide giving an idea of the extent of the environmental contamination problem (IHPA, 2006). Air releases of lindane can occur during the agricultural use or aerial application of this insecticide, as well as during manufacture or disposal. Also, lindane can be released to air through volatilization after application (Shen et al., 2004). Evaporative loss to air from water is not considered significant due to lindane’s relatively high water solubility (WHO/Europe, 2003).

Releases

Considering every ton of lindane produced generates approximately 6 - 10 tons of other HCH isomers, a considerable amount of residues was generated during the manufacture of this insecticide. For decades, the waste isomers were generally disposed of in open landfills like fields and other disposal sites near the HCH manufacturing facilities. After disposal, degradation, volatilization, and run off of the waste isomers occurred (USEPA, 2006). If the estimate of global usage of lindane of 600,000 tons between 1950 and 2000 is accurate, the total amount of possible residuals (if it is assumed that a mean value of 8 tons of waste isomers are obtained per ton of lindane produced) amounts to possibly 4.8 million tons of HCH residuals that could be present worldwide giving an idea of the extent of the environmental contamination problem (IHPA, 2006). Air releases of lindane can occur during the agricultural use or aerial application of this insecticide, as well as during manufacture or disposal. Also, lindane can be released to air through volatilization after application (Shen et al., 2004). Evaporative loss to air from water is not considered significant due to lindane’s relatively high water solubility (WHO/Europe, 2003).

Fate

Once released into the environment, lindane can partition into all environmental media. Hydrolysis and photolysis are not considered important degradation pathways and reported half-lifes in air, water and soil are: 2.3 days, 3-300 days and up to 2 to 3 years, respectively. A half-life of 96 days in air has also been estimated. Lindane can bio-accumulate easily in the food chain due to its high lipid solubility and can bio-concentrate rapidly in microorganisms, invertebrates, fish, birds and mammals. The bioconcentration factors in aquatic organisms under laboratory conditions ranged from approximately 10 up to 4220 under field conditions, the bioconcentration factors ranged from 10 up to 2600. Although lindane may bioconcentrate rapidly, bio-transformation, depuration and elimination are also relatively rapid, once exposure is eliminated.

Effects