CHLORINATED PARAFFINS: A STATUS REPORT
- Chapter 1 General Information About Chlorinated Paraffins
- Chapter 2 Health and Environmental Effects Research
- Chapter 3 Scientific Assessment by Regulatory Bodies and International Organizations
- Chapter 4 Relevant Regulations in North America
- Chapter 5 Environmental Management of Chlorinated Paraffins
This Status Report has been developed by the Chlorinated Paraffins Industry Association (CPIA). Its purpose is to summarize the existing information on the uses and chemistry of CPs; to discuss the scientific evidence on health and environmental effects; to relate the current status of CP evaluation and regulation by government agencies and in international scientific forums; and, to provide information on operational management and safe handling practices for CPs. This report updates CPIA's January 1990 Status Report.
||General Information About Chlorinated Paraffins
Chlorinated Paraffins (CPs) are a family of complex mixtures representing more than 200 commercial products. Use applications for chlorinated paraffins range from extreme pressure additives in lubricants, to secondary plasticizers in paints and plastics, to flame retardants in various plastics and textiles. Chlorinated paraffins are selected for these applications because they are safe, perform better and are more cost-effective than most available substitutes.
The Chemistry of CPs
Chlorinated paraffins are made by chlorinating the paraffin fractions obtained from petroleum distillation. The three most common commercial feedstocks used are straight chain paraffins with carbon number ranges of:
|Percent of Chlorination (by weight)
These hydrocarbons (also known as n-alkanes) are reacted with chlorine resulting in chlorinated paraffins with varying degrees of chlorination. The resulting chlorinated paraffins are a group of highly complex mixtures, comprised mainly of n-paraffins of 10-30 carbon atoms chlorinated from approximately 35% to greater than 70% by weight. The general formula for CPs is CxH(2x-y+2)Cly. The majority of CP products can be depicted in a 15-cell matrix, as shown in Figure 1 above.
The physical properties and performance characteristics of chlorinated paraffins vary by carbon chain length and degree of chlorination. Since all chlorinated paraffin products are mixtures, they have no fixed melting points or boiling points. Generally, the viscosity of the CP increases as either the chlorine content increases or the carbon chain lengthens.
Typically, short-chain chlorinated paraffins (C10-13, SCCPs) and mid-chain chlorinated paraffins (C14-19, MCCPs) are liquids at room temperature and normal pressure. The long-chain chlorinated paraffins (C>20, LCCPs), which are highly chlorinated, are resinous solids. The boiling points of CPs are usually above 200°C.
The percentage of chlorine also influences the ability of CPs to inhibit combustion. The higher the percentage of chlorination, the more effective the compound is as a flame retardant. For example, the flash point of the 50% chlorinated SCCP is about 166°C, while the flash point for SCCPs that are chlorinated more than 56% is more than 202°C. Comparably, the flash point of an MCCP product (C14-17, > 40% Cl) is more than 210°C.
The solubility of CPs in water (Sw) is very low and decreases with the increase of carbon chain length. Some SCCP mixtures (C10-13) are slightly soluble in water, ranging from 37 to 994 parts per billion (ppb) (Muir et al., 1999). For MCCP products with chain lengths between 14 to 17 carbons, the solubility ranges from 5 to 27 ppb. The water solubility for some of the long-chain mixtures (C20-30) is as low as 3.6 to 6.6 ppb (Campbell and McConnell, 1980).
CPs are, however, emulsifiable with water and can be blended with a wide variety of petroleum lubricating basestocks and other organic solvents. CPs are highly soluble in chlorinated solvents, aromatic hydrocarbons, esters, ketones and ethers; moderately soluble in aliphatic hydrocarbons; and only slightly soluble in lower alcohols.
In the normal working environment, CPs have low vapor pressure because of their high molecular weight. Still, the vapor pressure of individual CP isomers can cover a range of values. For an SCCP chlorinated to 50%, the vapor pressure was reported as 0.0021 Pa at 40°C. For a group of MCCPs (C14-17, 52% Cl), the vapor pressure was reported as between 1.3 to 2.7x10-4 Pa at 20°C (Campbell and McConnell, 1980). Henry's Law of Constants, which represents the vapor pressure of CPs in solution, has been reported for some SCCPs (C10-12) with ranges from 0.7 to 18 Pa m3/mol (Muir et al., 1999).
The octanol-water partition coefficients (Kow) of CPs are fairly large. The values of the logarithm of Kow range from 4.9 to 12 (Renberg et al., 1980). Kow is often used as an indicator of bioaccumulation because it can be easily measured and even calculated on the basis of molecular formula and structure.
Production and Use Patterns in North America
Over time in Canada and the US, the chlorinated paraffins manufacturing industry has consolidated. There are currently three major manufacturers (see Table 1) responsible for virtually all of the chlorinated paraffins produced in North America.
Table 1 - Major CP Producers in North America
|Dover Chemical Corporation
|Ferro Corporation, Petroleum Additives
|Pioneer Americas, Inc.
In the late 1970's, the manufacturers of CPs formed the Chlorinated Paraffins Industry Association (CPIA) as a forum for joint development and review of health and environmental effects information about CPs, and also to allow members to collectively address regulatory and product stewardship issues. All major North American producers are CPIA members. (Additional information on CPIA activities can be found at www.regnet.com/cpia. CPIA members work closely with their European counterparts who are organized under the Euro Chlor Chlorinated Paraffins Sector Group (www.eurochlor.org).
CPIA routinely conducts surveys on the production and sales of CPs in North America. These surveys reveal that the production and market demand for CPs has been relatively stable in recent years.
MCCPs represent the largest production and use category in North America (46.4%); LCCPs are second (33.1%); and, SCCPs account for the rest (20.5%).
The overwhelming use of CPs in North America overall is as additives in cutting oils and high pressure lubricating oils where the requirements for chemical stability are high. At high temperatures, these oils react to form low melting inorganic lubricant films on metal surfaces. This film prevents unwanted welding of metal parts.
In the plastics industry, chlorinated paraffins are often used as secondary plasticizers in polyvinyl chloride (PVC), where CPs enhance the plasticizing effects and are thus also known as "extenders." Secondary plasticizers are used in combination with primary plasiticizers, such as phthalates and phosphate esters. Chlorinated paraffins can be used as well in other plastics including flexible vinyl in the housing and automobile industries, acrylonitrile-butadiene-styrene resins (ABS), unsaturated polyester resins, polyethylene, polypropylene and urethane foam.
To a lesser degree, CPs are also commonly found in rubbers, paints, adhesives, caulks and sealants, and function as either plasticizers or flame retardants.
CAS Registry Numbers for CPs
CAS numbers have been assigned to various chlorinated paraffins. These CAS numbers may represent specific CP isomers or may reflect large categories of CPs (see Table 2). The generic CAS number 63449-39-8 is often used to denote chlorinated paraffin waxes of unspecified carbon chain length and degree of chlorination. The following identifies CAS numbers used on the US TSCA Inventory and on the Canadian Domestic Substance List (DSL).
Table 2 - CAS Numbers for Various Categories of Chlorinated Paraffins
|Alkanes C10-13, chloro
|Alkanes C14-17, chloro
|Alkanes C18-28, chloro
|Alkanes, C10-21, chloro
|Alkanes, C18-20, chloro
|Alkanes, C6-18, chloro
||TSCA & DSL
|Alkanes, chloro; chloroparaffins
||TSCA & DSL
|Alkanes, C12-13, chloro
|Alkenes, polymerized, chlorinated
||TSCA & DSL
|Alkenes, C12-24, chloro
||TSCA & DSL
|Paraffin waxes, chloro
||TSCA & DSL
||Health and Environmental Effects Research
During the mid-1970's, a collaborative effort among the CP producing industry, the US Environmental Protection Agency and the National Toxicology Program (NTP) began a comprehensive health and environmental research and review program for CPs. The objective was to better understand the health and environmental effects associated with exposure to chlorinated paraffins. This work was completed in the early to mid-1980's and represents an extensive body of information on CPs. A summary of these results was complied by Serrone et al.
This comprehensive test program has provided the basis for many CP reviews and risk assessments by various governments and other international organizations. As new questions emerge, the industry has maintained an active program of reviewing new findings and conducting additional studies to better understand the health and environmental effects. For example, in the past several years new mechanistic research has evaluated the relevance to man of some of the animal toxicology studies. Additionally, the industry has a program underway to assess the environmental fate and effects of CPs including a review of analytical methods for measuring CPs in the environment, clarifying acute toxicity studies to select aquatic species, and establishing the biodegradation potential of some CPs in the aquatic environment. Following is a summary of the latest scientific information on CPs and their relevance to assessing the potential risk of CPs to human health and the environment.
Synopsis of Animal Toxicological Data
Acute Toxicity - The acute oral toxicity of chlorinated paraffins has been tested in a large variety of animal species and is consistently found to be very low. Because the toxicokinetic data indicate that CPs are poorly absorbed via the dermal route, the acute dermal toxicity of CPs is very low.
Repeated Doses - In subchronic studies in mice, rats and dogs, the liver was determined to be a primary target organ for CPs. No observed adverse effect levels (NOAELs) were established with considerably higher values found for longer chain CPs.
Genetic Toxicity - Bacterial mutagenic in vitro and in vivo studies on SCCPs, MCCPs, and LCCPs have all been negative, supporting the contention that CPs are not mutagenic (Birtley et al., 1980). Additionally, no chromosomal aberrations were observed in dominant lethal studies in rats (Serrone et al., 1987).
Teratogenicity and Reproduction Toxicity - Teratology tests all showed negative results. In 1993, EPA determined that multi-generation reproduction tests were not necessary.
Carcinogenicity - Results of the National Toxicology Program's (NTP) cancer testing of two CPs -- a C12 chain length, 60% chlorine CP and a C23 chain length, 43% chlorine CP -- were announced in August 1985. NTP interpreted these studies to show:
- For the short-chain material, clear evidence of carcinogenicity in both sexes of rats and mice; and,
- For the long-chain material, no evidence of carcinogenicity in male rats, equivocal evidence in female rats, equivocal evidence in female mice, and clear evidence in male mice.
On the basis of these cancer studies, the NTP concluded "there is sufficient evidence for the carcinogenicity of chlorinated paraffins (C12 60% chlorine) in experimental animals." Thus, the short-chain material that was tested was listed as a suspect carcinogen by NTP in the Fifth Annual Report on Carcinogens, released in late 1989.
Based on its review of the NTP studies, the International Agency for Research on Cancer (IARC Monograph, Vol. 48) concluded:
Chlorinated paraffins of average carbon chain length C12 and average degree of chlorination approximately 60% are possibly carcinogenic to humans (Group 2B) (IARC Monograph, Volume 48).
The IARC Group 2B rating reflects the dual consideration of the absence of any human data suggesting CPs cause cancer and the sufficiency of evidence for carcinogenicity in experimental animals exposed to C12 60 % chlorinated CP.
The Group 2B classification is limited to the short-chain, C12 60% material. IARC concluded that there was "limited evidence" for the carcinogenicity of a commercial chlorinated paraffin product of average carbon chain length C23 and average degree chlorination 43% in experimental animals. IARC did not suggest any conclusions regarding the carcinogenic potential to humans of the C23 material or of any other chlorinated paraffin compound.
As part of a Toxic Release Inventory rulemaking, EPA conducted an in-depth review of the NTP research on the C23 long-chain CP product. The Agency found NTP's initial characterization incorrect and concluded that "long-chain chlorinated paraffins should not be classified as potential carcinogens." (Emphasis supplied, 59 FR 61462)
Considerable effort has been devoted to understanding the significance to man of cancer in the thyroids, livers and kidneys that were reported in the mid-1980 NTP rat and mouse studies. It is well known that experimental animals of the type used in the NTP research have metabolic systems which operate differently from those of humans; and, these animals frequently display adverse effects in the organs seen in the short-chain study which do not occur in people. In 1997, a Panel of Specialized Experts reviewed this whole body of animal data on the short-chain material, including newly reported mechanistic data, as part of the European Union's (EU) risk assessment review of short-chain chlorinated paraffins. They concluded that the NTP research results showing cancer in the thyroid and liver were not relevant for human risk assessment. Research to understand the kidney cancers seen in male rats continues.
Environmental Fate and Effects of Chlorinated Paraffins
Environmental releases of chlorinated paraffins can occur anywhere along the life-cycle chain from manufacture, transport, use, to disposal. However, it is widely agreed, because manufacture and transfer occur within closed systems, that the most likely source of releases comes from use and disposal in dispersive use applications such as metalworking.
The most ecologically significant impacts occur when CPs are released to water and sediment. Because of their low solubility in water, they are thought to be transported in water by adherence to particles and are strongly adsorbed to sediment. In air, CPs are thought to travel in a similar fashion by adhering to particles. (IPCS, 1996, EPA, RM2)
Monitoring data for CPs in water are limited. Researchers have reported detection of CPs at low ng/L levels in natural water bodies including in remote regions. SCCPs have been reported in filtered Canadian river water at 18.6 to 49.7 ug/l (micrograms/ liter which equals parts per billion [ppb] (Muir, et al., 1996). In the United Kingdom, higher measurements of 4 ug/l in marine water and 4 ug/l in fresh water have been reported. Very high levels have been measured in sediment adjacent to manufacturing facilities but these are generally old and not considered relevant to modern day operations. (IPCS)
Studies have shown that SCCPs with 50% chlorine are rapidly and completely degraded over a 25-day test period under aerobic conditions, but an increase in the chlorine level to 58% inhibited degradation (Madeley et al.). There are limited biodegradability data available for MCCPs and LCCPs; however, it is thought they degrade more slowly than short-chains.
CPs in the air tend to photo-degrade by reacting with hydroxyl radicals. The half-life of SCCPs in the air have been calculated to range from 1.2 to 1.8 days (Slooff et al., 1992). Based on the same kinetics model of hydroxyl radical reaction (Atkinson et al., 1986), the half-lives of MCCPs (C14-17) and LCCPs (C18+) have been calculated by Tomy et al., 1997. These researchers determined a half-life of 0.85 to 1.1 days for MCCPs and 0.5 to 0.8 days for LCCPs respectively. The rate of photodegradation is inversely proportional to the chain length (Willie et al., 1994).
In aquatic systems, where CPs are generally associated with sediment or suspended particles because of their low solubility, K. Freisen et al. (1999) have shown that the presence of reactive free radicals (e.g., hydroxyl radicals) may induce significant photodegradation of CPs. In an experiment carried out in natural waters (from three lakes in Northern Ontario), in the presence of simulated sunlight, it was found that the half-life of 1,12-dichrolododecane was as low as 4.1 to 5.8 days.
Chlorinated paraffins have the potential to bioaccumulate in aquatic organisms. The bioconcentration factor (BCF) or bioaccumulation factor (BAF) is often used to measure the ability of a chemical to bioaccumulate in a species. Compounds with BAF or BCF values of more than 1,000 in fish are susceptible for bioaccumulation.
Laboratory studies have shown slight bioaccumulation occurring in mussels and rainbow trout. The BCF for SCCPs in rainbow trout ranged from 1173 to 7816, varying by the concentration of exposure (Madeley et al., 1983). The same research also reported a considerably higher BCF of 40,900 for SCCPs in common mussels. In fish, SCCPs are accumulated to a greater degree than are the long- or mid-chains.
Eco-Toxicity - The primary concern about SCCPs in the environment is their inherent toxicity to aquatic species. There is a complete set of acute toxicity studies for SCCPs at three trophic levels (Algae, Daphnia and Fish). Only when studies were extended to 60 days, could the toxicity of SCCPs be shown in the rainbow trout and mussels. Concentrations of SCCPs (C10-13) between 12 and 30 parts-per-billion (ppb) reduced the growth of mussels and were lethal to some trout; however, higher levels of the same material (up to 280 ppb) had no effect on the growth or viability of the sheepshead minnow. The maximum acceptable concentration (i.e., a concentration that did not produce significant adverse effects in the test species) was determined to be 100 ppb for the midge (an organism that lives in sediment on the bottoms of streams and ponds).
SCCPs were also found to affect adversely the reproduction of certain small crustacean species. Concentrations of short-chain CPs (C10-13) in water, under laboratory conditions, at or about 10 ppb adversely affected reproduction of the water flea (daphnia) and the mysid shrimp. Though it is of concern that the relatively low concentration of short-chain CPs was found to be toxic in the environmental laboratory studies, it should be observed that SCCPs at such levels are not generally found in aquatic media.
Acute toxicity data on MCCPs are available in fish, Daphnia, mussel and algae. Daphnia was the only species associated with findings of toxic effects (Thompson et al., 1997). Ongoing analysis may offer a basis for explaining the research conclusion in the daphnia.
There are considerably fewer ecotoxicity data for LCCPs since these compounds are considered less toxic than MCCPs and SCCPs.
Human Exposure - The predominant route of human exposure is through skin contact because CPs are viscous liquids or waxy solids with very low vapor pressure that do not readily volatilize. Because CPs are poorly absorbed through the skin, there have been no case reports of skin irritation or sensitization.
Little CP exposure via consumer products is expected, because the CPs are bound in the products they are in, e.g., paint, plastic. It is likely that humans may come in contact with CPs via food and water because trace amounts of CPs have been detected in the aquatic environment. The EU has estimated that the maximum daily human intake of SCCPs was around 2.2-2.5 µg/kg, well below any levels of concern.
||Scientific Assessment by Regulatory Bodies and International Organizations
US EPA's Assessment from 1977 to 1994
In 1977, an International Consortium of Chlorinated Paraffin (ICCP) manufacturers met with EPA and obtained Agency endorsement of a testing program to assess the health and environmental effects of CPs. When CPs were officially nominated for health and environmental effects testing in 1979 by the Interagency Testing Committee, the research program was already well underway. In 1982, EPA approved the industry program as a substitute for a mandated test rule under the Toxic Substances Control Act (TSCA) (47 FR 1017, January 8, 1982). EPA's acceptance recognized that a short-chain and a long-chain CP were going to be tested by the NTP in their carcinogenesis bioassay program.
EPA's chemical risk management (RM) process review of CPs was done in two steps. In June 1991, EPA published its RM1 risk assessment for CPs. EPA found that the C10 - 13 58% SCCP was the most toxic to aquatic life, and that the greatest potential risk was from the release of CPs to the aquatic environment from its use in water soluble metalworking fluids. EPA also concluded that there was minimal risk associated with the use of CPs in straight oils, as these fluids were not likely to be discharged into the environment. The report recommended that CPs be referred to the RM2 phase for, among other things, consideration of pollution prevention measures.
In 1992, CPIA, in cooperation with Independent Lubricant and Manufacturers Association (ILMA), voluntarily undertook a survey that compiled detailed information from formulators on the composition and distribution of their metalworking fluids. The survey results accounted for more than 70% of the estimated total domestic sales of SCCPs and short-chain chlorinated alpha-olefins used in water soluble fluids. In the RM2 phase of review, EPA undertook an evaluation of the CPIA survey data to determine the concentrations, and therefore the degree of risk, that might be expected from SCCPs in the aquatic environment. This analysis targeted the four highest use states (Ohio, Michigan, Illinois, and Indiana) and estimated SCCP concentrations in 248 localities. Assuming 90% reduction of CPs through pre-treatment before disposal, EPA derived a formula to estimate CP concentrations in receiving waters.
The Agency also established a range of "concern levels," including the "No Observed Effect Level" (NOEC) for SCCPs of 1.0 - 5.0 ug/l and a "Lowest Concern Level" of 0.03 ug/l. EPA's analysis found that 186, or 75 percent, of the 248 localities reporting would have in-stream concentrations below even the lowest level of concern. Using worst case assumptions, EPA further determined that at only three out of 248 locations would CP concentrations potentially exceed the NOEC.
With respect to human health, also addressed in the RM2 assessment, EPA expressed a moderate concern for metalworkers exposed to oil mist through inhalation and a lesser degree of concern for dermal exposures. EPA also examined the risk of subsistence fish eaters in the heaviest use areas, but determined this exposure represented a negligible population risk.
Based on its RM2 evaluation, EPA determined that there was no need to impose restrictions on the use of SCCPs. EPA did, however, decide to require annual reporting on the release of short-chain chlorinated paraffins on the Toxics Release Inventory (TRI, discussed in Chapter 4).
Assessment of SCCPs in Canada from 1989 to present
PSL 1 Listing
As mandated by the Canadian Environmental Protection Act (CEPA), in 1989, Canada posted short-chain chlorinated paraffins on its first Priority Substances List (PSL). As part of the PSL process, Canada undertook a general review of the scientific information on chlorinated paraffins for all three chain lengths. In 1993, Canada determined that SCCPs were "probably carcinogenic to humans," and therefore "toxic" under CEPA Section 11(c). (Note: The mechanistic information on SCCPs was not available at the time Canada completed its health effects review.) The same review concluded that there were insufficient data to determine whether SCCPs would "have an immediate or long-term harmful effect on the environment" under CEPA Section 11(a).
In accordance with its Strategic Options Process, Environment Canada established an "Issue Table" made up of representatives of government, industry and public interest groups to consider risk management measures to control the use of SCCPs. Principally as a result of the establishment of a new Toxic Substances Management Policy (TSMP), the activities of the SCCP Issue Table have been suspended over the past several years.
Track 1 Under TSMP
In March 1997, following adoption of its Toxic Substances Management Policy, Canada proposed to list SCCPs as a Track 1 substance along with 12 other compounds. Track 1 is one of two options under the TSMP, and it aims to "virtually eliminate" toxic, persistent and bioaccumulative compounds which result from the activities of people (anthropogenic activities). Track 2 focuses on life-cycle management of substances of concern in Canada.
Unlike the 1993 review that designated SCCPs "CEPA toxic" for human health, the Track 1 assessment focused on the persistence, bioaccumulation and environmental toxicity. To qualify as Track 1, a substance must be persistent in at least one environmental medium (air, water, soil and sediment); must bioaccumulate (as indicated by either BAF, BCF or Kow data); and be toxic.
In its Justification for listing, Canada suggested that SCCPs met all the Track 1 criteria. However, contrary to the 1993 evaluation, the CEPA toxic determination was based solely on a review of the environmental data relating to risk posed by SCCPs in the aquatic environment. In its comments on the Justification in May 1997, CPIA raised significant technical objections to the scientific basis for the persistence findings, and to the lack of evidence that SCCPS exist in the Canadian environment at toxic levels.
On July 4, 1998, Environment Canada published a Notice in the Canada Gazette (Part 1) of its final determination to list the other twelve substances originally designated with SCCPs for Track 1 consideration. Subsequently in August, by letter to interested parties, Environment Canada affirmed that "no action will be taken on SCCPs until a decision is made regarding SCCPs' toxicity under the Canadian Environmental Protection Act 11(a) of CEPA." To date, no further formal action has been taken on SCCPs.
In the past year, there have been new reports on the presence of trace levels of SCCPs in remote regions. Most of these reports are from Canadian researchers who claim they have measured minute concentrations of SCCPs in remote regions such as the Arctic. Since the TSMP provides for the use of information documenting long-range transport as a surrogate for demonstration of persistence in air, CPIA has initiated a program to assess the reliability of the analytical techniques use by the Canadian researchers.
The EU Risk Assessment on SCCPs
The European Union (EU) is at the end of a long process of conducting a full risk assessment and risk reduction strategy (RRS) development on SCCPs under the EU Existing Substances Regulation (EEC 793/93). The final risk assessment concluded that, "a risk to aquatic organisms exists arising from the local emission of short-chain length chlorinated paraffins from metal working applications."
The difference in outcomes between the US and EU risk assessments and regulatory determinations for SCCPs reflects a fundamental difference in philosophy and procedures relating to chemical regulations. The EU is guided by a "precautionary principle," which provides for the application of conservative assumptions about exposure and risk in the absence of definitive scientific information. In its hazard analysis for SCCPs, the EU estimated the concentrations of SCCPs in receiving water, soil and sediment based on assumptions of relatively high concentrations of SCCPs being released from wastewater treatment plants. It then set its "predicted no effect concentration" (PNEC) and calculated, based on worst-case assumptions, predicted environmental concentrations (PEC). The EU concluded that an excessive number of sites would be subject to SCCP levels above the PNEC. Hence, the risk was determined to be unacceptable, requiring regulatory restrictions on use.
With respect to human health (as was discussed in Chapter 2), the EU convened a Panel of Specialized Experts to review the available mechanistic information. The Panel concluded that for purposes of human health risk assessment, except the kidney tumors in male mice, the tumors seen in the animal studies were not relevant to man. For the kidney, additional research was recommended which is currently underway. The risk assessment further concluded that risks to human health through occupational exposure and to the general population through use in products such as paints and rubber are being adequately managed, and no additional controls are needed.
SCCP Review by the OECD
In November 1999, a meeting to review risk management options for SCCPs was sponsored by the Organization for Economic Cooperation and Development (OECD) in Geneva, Switzerland. Many governments were represented including the US, Canada, Germany, UK and Japan, as was CPIA and representatives of European producers. Both the US EPA and CPIA discussed the significant differences in the exposure assumptions and the risk characterizations between the EU and the US. CPIA emphasized that pollution control management options exist for SCCPs for the majority of use scenarios which are adequate to protect the aquatic environment.
International Programme for Chemical Safety
A review of chlorinated paraffins was prepared by the International Programme for Chemical Safety (IPCS), which is a collaboration among the United Nations Environment Program (UNEP), the World Health Organization (WHO), and the International Labour Organization (ILO). The IPCS "Environmental Health Criteria 181: Chlorinated Paraffins" (1996), concluded that SCCPs "are acutely toxic to freshwater and saltwater invertebrates." With respect to people, the IPCS concluded "provided that proper industrial hygiene and safety procedures are followed, the risk to the health of workers exposed to chlorinated paraffins is expected to be minimal."
The UN/ECE POPs Protocols
In 1994, the United Nations Economic Commission for Europe (UN/ECE) began negotiations to develop an international protocol to control persistent organic pollutants (POPs). This POPs protocol was part of the Convention on Long-Range Transboundary Air Pollution (LRTAP), intended to ban the production and use of POPs in UN/ECE member countries. To qualify for listing as a UN/ECE POP, a substance must be capable of long-range environmental transport, persistent in environmental media, capable of bioaccumulating in organisms and toxic to humans and/or environmental species.
Short-chain chlorinated paraffins were included as a candidate for the initial UN/ECE POPs list. However, the US government and the CP producing industry objected, arguing there is a lack of evidence that SCCPs are persistent in the environment or capable of long-range transport. In early 1998, the UN/ECE declined to include SCCPs in the finalized POPs list.
In the summer of 1998, the United Nations Environment Programme (UNEP) began negotiations for a treaty to control health and environmental threats from chemicals that persist in the environment. The UNEP agreed upon an initial list of 12 chemicals which does not include chlorinated paraffins. The year 2000 is the target for concluding the treaty, which would bind all member governments to reduce and eventually eliminate the listed POPs.
||Relevant Regulations in North America
There are no restrictions on the manufacture, processing and use of CPs in the United States. Moreover, there are no activities pending to consider imposing any new restrictions.
EPCRA, Toxic Release Inventory (40 CFR 372)
On November 30, 1994, EPA expanded the list of chemicals subject to the Toxics Release Inventory (TRI) reporting requirements (59 FR 61432). Included on the expanded list was a category of "polychlorinated alkanes (C10-13)," the bulk of which are short-chain chlorinated paraffins. Initially, EPA proposed to add all CPs to the TRI, but eventually agreed with the CPIA that there was no justification for adding mid- and long-chain CPs.
The regulations impose customer notification and environmental release reporting obligations on high volume manufacturers, formulators and users of these materials. Reports for the prior calendar year are due to EPA on July 1 of the following year. A facility is subject to reporting if it meets all three of the following criteria:
- It is included in a covered Standard Industrial Classification (SIC codes 20 - 39);
- It has ten or more full-time employees (or the equivalent of 20,000 hours per year); and,
- It manufactures, imports, processes or otherwise uses any of the toxic chemicals listed on the EPCRA section 313 list in amounts greater than the "threshold" quantities specified below.
The threshold quantity for facilities that manufacture, import or process chemicals is 25,000 pounds over a calendar year. If the facility only uses a chemical, the threshold quantity is 10,000 pounds per year. To determine whether the rule applies to a particular facility, it is necessary to consider the aggregate quantity of all "polychlorinated alkanes (C10-13)" processed or used in that facility over a year.
As a general rule, for purposes of evaluating mixtures, only TRI chemicals present in concentrations greater than 1% must be included in the threshold calculation to determine the total quantity of the TRI chemical present. There is an exception for suspect carcinogens, which must be reported if they are present at concentrations greater than 0.1%. The only SCCP where this rule applies is the C12, 60% Cl formulation, since this product has been classified as a suspect carcinogen by the National Toxicology Program; for all other short-chain materials, the threshold calculation is based on the presence in mixtures at concentrations greater than 1%.
Specific guidance on the TRI reporting requirements for polychlorinated alkanes can be found at: www.epa.gov/tri/guidance.htm.
TSCA, HPV Programs (40 CFR 710)
US EPA included both chlorinated paraffins (CAS number 63449-39-8, 61788-76-9, 68920-70-7) and chlorinated olefins (CAS number 68410-99-1) on the 1990 High Production Volume (HPV) Chemical List. The purpose of the EPA HPV program list is to provide basic hazard information about chemicals that are produced or imported in quantities greater than one million pounds per year. There are 2863 organic chemicals currently on the HPV list. The Toxic Substances Control Act (TSCA) gives EPA limited authority to require the manufacturers to test these chemicals and impose controls when necessary.
The HPV Challenge program invites chemical companies to make voluntary commitments to test the HPV chemicals and to schedule the tests. Participating companies are to: assess the adequacy of existing data; design and submit test plans; provide test results; and, prepare robust summaries of the data characterizing each chemical according to EPA's guidance.
In February 1999, CPIA committed to submit to EPA all necessary health and environmental information for the chlorinated paraffins and chlorinated olefins listed as HPV chemicals.
RCRA, Hazardous Waste and Used Oil Rules (40 CFR 260-299)
Chlorinated paraffins are not regulated hazardous wastes under the Federal Resource Conservation and Recovery Act (RCRA) system. Nonetheless, because many chlorinated compounds have been the focus of regulatory attention, questions are often raised about proper disposal practices for used CPs.
A waste is deemed "hazardous" under RCRA if EPA has included it on the list of hazardous wastes (40 CFR §261, Appendix VIII); or if it meets one of four general hazardous waste characteristics: Ignitability, Corrosivity, Reactivity and EP Toxicity; or if it is found above specified concentrations in a specially designed leaching procedure (TCLP). Used CPs, unless mixed with other "hazardous" substances, do not generally meet any of these hazardous waste characteristics.
Used oils containing CPs require some scrutiny concerning compliance with RCRA. At one time, EPA proposed listing all used oil as a RCRA hazardous waste, including metalworking fluid containing cutting, grinding, machining rolling, stamping quenching and tempering oils (50 FR 49258, Nov. 29, 1985). The Agency subsequently decided against listing used oil as hazardous.
However, according to 40 CFR 279, used oil containing more than 1,000 ppm total halogens is presumed to be a hazardous waste because it may have been contaminated with listed halogenated hazardous wastes. CPs can cause used oils to exceed the halogen limit. The regulations allow individuals the right to rebut the hazardous waste presumption by demonstrating (for example, by using an analytical method listed in 40 CFR 261, Appendix VIII) that the high halogen levels come from chlorinated paraffins, and not from chlorinated solvents.
It is not necessary to rebut the presumption in the case of metalworking oils/fluids containing chlorinated paraffins, if they are processed, through a tolling agreement, to reclaim metalworking oils/fluids (40 CFR 279).
Used oil that is burned for energy is regulated under 40 CFR 266. These regulations are less comprehensive than those governing hazardous waste, and would apply to used oil containing CPs so long as no hazardous waste were also present.
EPA has banned land disposal of liquid hazardous wastes containing certain halogenated organic compounds (HOCs) in concentrations above 1,000 mg/kg (0.1%) (40 CFR 268.32). This land ban only applies to HOCs which are listed as hazardous (52 FR 25770, July 8, 19985). CPs are not on that list (40 CFR 268, Appendix III).
OSHA Hazard Communication Standards (29 CFR 1910.1200)
CP manufacturers have for many years made Material Safety Data Sheets (MSDSs) available to their customers. Since 1983, the Occupational Safety and Health Administration (OSHA) has imposed additional worker training and communication requirements for all hazardous chemicals. Pursuant to the OSHA Hazard Communication Standard, hazardous materials must be labeled with the appropriate hazard warning, and MSDSs detailing hazards must be available to workers.
Manufacturers are required to evaluate existing scientific data and label compounds for which available evidence indicates the potential for toxicity. MSDSs require even more extensive health effects information.
OSHA's interpretive guidelines for hazard communication require a special cancer warning on the label of compounds identified as carcinogens or probable carcinogens by: 1) the NTP in its Annual Report of Carcinogens; 2) the International Agency for Research on Cancer (IARC); or, 3) OSHA itself. Since both the IARC classification and the NTP Fifth Annual Report on Carcinogens have designated the C12, 60% Cl chlorinated paraffin as a carcinogen, the cancer label is required on any product containing more than 0.1% of that product. A cancer label is not required for any other short-chain; nor is it required for the C23 43% Cl long-chain CP that NTP tested since that product was never designated by IARC, NTP or OSHA.
Material Safety Data Sheets also provide information on safe handling practices. The information provided below briefly summarizes the safe handling recommendations in the MSDSs routinely supplied by CPIA members.
Table 3 - Safe Handling Practices for CPs
||Normally not needed; For oil type mist, use NIOSH approved respirator
||Special ventilation not required under normal conditions of use
||Use impervious gloves
||Use chemical goggles or face shield
|Other Protective Measures
||Clean clothes; Use apron or chemical suit where splash can occur
California's Proposition 65
California Proposition 65 imposes strict rules on discharges of, and exposure to, chemicals known to the State to cause cancer or to be reproductive toxicants.
In April 1989, the California Science Advisory Panel (SAP) added to its list of chemicals subject to these requirements the chlorinated paraffin "C12 60% chlorine." This is the same CP that was listed by IARC and NTP. Other CPs have not been listed by SAP.
As a result of the listing of the C12 60% chlorinated paraffin, the public is to be notified of any significant exposures to this compound. In addition, discharges of significant amounts of this compound to drinking water are prohibited. California has yet to determine what is to be considered a significant exposure to C12 60% chlorine CP. Users of chlorinated paraffins should consult their Material Safety Data Sheets to determine whether a product contains a Proposition 65 chemical.
It should also be noted that some chlorinated paraffin products may be affected by Proposition 65 because they contain other chemical substances that are found on the California list. For example, resinous chlorinated paraffins, which are generally highly chlorinated (approximately 70%), often contain residual concentrations of carbon tetrachloride. Since carbon tetrachloride is on the California list, products containing carbon tetrachloride may be affected.
National Pollutant Release Inventory
On April 24, 1999, Environment Canada added SCCPs to the list of chemicals subject to reporting pursuant to the Canadian National Pollutant Release Inventory. Two CAS numbers were specified: Alkanes, C6-18 Chloro CAS number 68920-70-7, and Alkanes, C10-13 Chloro CAS number 85535-84-8. The NPRI regulations are similar to the US Toxic Release Inventory, and can be found at http://www2.ec.gc.ca/pdb/npri.
Generally, any facility in Canada which manufactures, processes and otherwise uses SCCPs subject to this rule must complete and file an electronic form describing environmental releases, off-site transfers and pollution prevention activities.
Small facilities whose employees work less than 20,000 hours or which does not meet the 10 metric tons reporting threshold are exempted from requirements of this rule. Only the quantity of an NPRI substance present at concentrations greater than 1% by weight, plus the quantity present as by-products at any concentration, need to be considered in the threshold calculation.
CEPA Toxic Determination
Environment Canada has declared SCCPs to be "toxic" under CEPA Section11(c). This triggered the formation of an Issue Table to determine the most cost-effective management option(s) to reduce the releases and exposures to these materials. As discussed in Chapter 3, the CPIA is advocating that SCCPs can be effectively managed through process controls and disposal restrictions. The Issue Table has been suspended while Environment Canada considers the Track 1 listing of SCCPs under the Canadian Toxic Substances Management Plan.
The CPIA is working closely with Environment Canada and monitoring any new development that may affect the future status of SCCPs in Canada.
||Environmental Management of Chlorinated Paraffins
Members of CPIA and many companies who produce and use chemicals in the US, Canada and Europe subscribe to the tenets of the Responsible CareÒ program. Commitment to this code ensures an enhanced level of environmentally conscientious operation by chemical manufacturers. Programs such as ISO 9000 and 14,000 (International Standards Organization) outline the specification of environmental performance for products, operations and management that apply to chemical users as well as to manufacturers.
In this spirit, many industry groups have developed environmental guidelines for operations within their own specialties. This is the case with metalworking, where the Organization Resources Counselors (ORC), in conjunction with the Metal Working Fluids Product Stewardship Group (MWFPSG) of the Independent Lubricant Manufacturers Association (ILMA) has published "Management of the Metal Removal Fluid Environment." This guide, which is available on the worldwide web (www.aware-services.com/orc), provides directions for the complete range of environmental and worker protection issues involved with metalworking fluids.
THE ORC/ILMA guide highlights two basic concepts for managing metalworking fluids (MWFs) in the environment. The first involves maintaining the integrity of the MWF so that waste generation is minimized. The second addresses oil/chemical separation from water for recycling or disposing of the oil/chemicals and proper treatment and disposal of the water. The ORC/ILMA guide outlines a number of operating procedures for recycling MWFs, including filtration, vacuum distillation, adsorption filtration, centrifugation and gross settling.
Proper disposal of water soluble MWFs requires treatment to separate the oil and other contaminants prior to disposal of the residual water. In the US, National Pollutant Discharge Elimination System (NPDES) permits specify the level of contaminants allowed in the water being discharged to receiving waters.
CPIA endorses product stewardship and chemical management programs such as that illustrated by the ORC/ILMA guide as opposed to banning or restricting use of beneficial chemicals which can be safely managed. Chemicals are a cornerstone of life in complex, industrialized countries. The best and most prudent course is to learn about how these materials behave in the environment and then to manage their use to minimize any adverse effects to man and the environment.