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Identification and assessment of alternatives to selected phthalates SummaryIn this study a number of alternative plasticisers to the phthalates DEHP, DBP and BBP are described and assessed. Suitable alternative plasticisers have been identified for most applications of the phthalates, and 10 of these have been assessed in detail. Some of the assessed alternative plasticisers have a broad application scope, others are more specialised. Plasticiser alternatives to DEHP, first of all the plasticisers DINA, DINCH, DEHT, ATBC and ASE are marketed at somewhat higher to significantly higher prices than the price of DEHP. The results of the assessment further indicate that alternatives to DBP and BBP are available for the major applications of the substances, at prices quite similar to the prices of the phthalates. All 10 assessed substances are expected to have low acute toxicity based on animal studies. For three of the assessed alternatives data exists demonstrating that they cannot be considered CMR substances (carcinogenic, mutagenic, reprotoxic); for the other alternatives data for at least one critical parameter are missing. The toxicological data for DEGD and DGD, two of the available alternatives to DBP and BBP in polymeric applications (plastics), indicate that the substances might be some effect on reproduction, but the results are not statistically significant and more data are necessary for a clear conclusion. With regard to the environmental properties, none of the 10 studied alternatives meet the criteria for being PBT substances (persistent, bioaccumulative and toxic in the aquatic environment) or vPvB substances (very persistent and very bioaccumulative), although all substances except GTA show one or two of these properties. Ortho-phthalates are a group of substances which have together proven to be widely applicable for plasticising purposes. Especially the general plasticisers DEHP, DINP and DIDP have had high importance due to their very wide applicability in PVC. DBP and BBP are specialty plasticisers which in polymer applications typically have been used together with other plasticisers in order to obtain specific processing conditions or material properties. The wide range of applications combined with comparatively low prices have made the ortho-phthalates the preferred choice of plasticiser for the PVC industry for many years and phthalates account today for about 90% of the total plasticiser use for PVC in Europe. This percentage has been quite stable for the last ten years only the distribution between the different phthalates has changed. The consumption of DBP and BBP has decreased markedly the last 15 years and the manufactured volume of each of the substances is today approximately 1% of the total manufactured phthalates. DINP and DIDP have become dominating alternatives to DEHP due to their closeness in performance to DEHP and only moderately higher costs. DINP or DIDP can replace DEHP for practically all applications and the price is approximately 10% higher than the price of the DEHP. DINP and DIDP have not been further assessed in this study because they are already well described and finished EU risk assessments are available for these substances. Information on alternatives to DEHP, DBP and BBP, actually applied today, has been collected from the following data sources:
These data sources have been supplemented with information from the literature and manufacturers' web sites. As consequence of the prohibition of DEHP, DBP and BBP in toys and childcare articles and the prohibition of DINP, DIDP and DNOP in toys and childcare articles which can be placed in the mouth by children, experience exist in substitution of the phthalates for these products. Dutch surveys of plasticisers in toys demonstrate that DEHP and DBP a few years ago could be found in a significant percentage of all samples. In accordance with the fact that the major uses of BBP are in flooring and non-polymer applications (e.g. adhesives) BBP was only found in a few of the toy samples and the surveys of plasticisers used in toys would not give any indication of which plasticisers are applied as alternatives to BBP. Table 0.1 lists plasticisers used in toys and childcare products. The substances reported by Danish manufacturers have specifically been used by the manufacturers as substitutes for phthalates, whereas some of the plasticisers reported in the surveys of plasticisers in toys and childcare products from other EU countries may in fact not have substituted a former use of phthalates. Three of non-phthalate plasticisers were found in a significant percentage of the samples in both surveys and are reported by all responding Danish manufacturers of toys as used as alternatives to phthalates: DINCH, DEHT and ATBC. All three are marketed as general plasticiser alternatives to DEHP. Among the non-phthalate plasticisers there seems not to be one substance that can make a one-to-one substitution for all applications of each phthalate. Which substitutes are suitable depends on the actual processing conditions and the desired properties of the final product. Finding the right plasticiser for a given application is often a complex process, as many technical criteria have to be met simultaneously. Comprehensive testing of the performance of the polymer/plasticiser system is often required. By way of example one Danish manufacturer reports that the development led to the use of a mixture of ATBC, DINCH and DEHT, which could be blended in a variety of combinations to achieve softened PVC that performed to the required standards with the existing production setup. On request a number of manufacturers of plasticisers have provided information on their market experience with possible alternatives to DEHP, BBP and DBP. Unfortunately the manufacturers of DINCH and DEHT, widely used in toys, did not provide detailed information, and the assessment of these substances has mainly been based on information from the manufacturers' websites and the literature. Both substances are marketed as general plasticisers for PVC. Based on information on the plasticisers found in toys and childcare articles and initial information from manufacturers, a gross list of 25 potential non-phthalate alternatives was compiled and from this list 10 plasticisers were selected for further assessment. Benzoates (represented in Table 0.2 by DGD and "Mix of DGD, DEGD, TGD") have been the main alternative to BBP, because they provide both suitable processing conditions and properties of the final products and have quite similar price. BBP is mentioned as a critical component in seals for insulating double glazing and it cannot be ruled out that niche applications of BBP and DBP exist where alternatives are not suitable. Click here to see: Table 0.1 Plasticisers found in toys and childcare articles Experience in the use of alternative plasticiser exists for all major applications of DEHP, DBP, and BBP. Experience for 6 of the selected plasticisers, for which detailed information was obtained is shown in Table 0.2. Note that the alternatives typically do not substitute for the phthalates 1:1; often are more substances used in combination.
*1: Market experience categories interpretation: 1) Main alternative on market. 2) Significant market experience. 3) Examples of full scale experience. 4) Pilot/lab scale experience The non-phthalate alternatives to DBP and DEHP have until now primarily been used for particular applications. DBP is in polymers typically used in relatively low concentration in combination with DEHP and the whole plasticiser system is replaced by other plasticiser systems. A summary of the technical suitability of the 10 alternatives and their prices relative to DEHP, DBP and BBP is provided in Table 0.3.
Notes: *1: Based on comparison with DEHP, but DBP and BBP are reported to have similar price and the notation therefore serves as indicating price relative to DBP and BBP as well. "≈" means similar price or slightly lower or higher than DEHP; "+" means somewhat higher price (10-50% higher) than DEHP and "++" means significantly higher price than DEHP. The report provides actual price examples. Price of alternatives As shown in the table above, the price of the non-phthalate alternatives DEHT, DGD and Benzoflex 2088 were in the same price range as the price of DEHP, DBP and BBP, (as well as the ortho-phthalate alternatives DINP and DIDP), whereas ASE, DINA , DINCH and GTA were somewhat more expensive and ATBC and COMGHA were considerably more expensive. The content of DEHP in plasticised PVC is typically 30% of the plastics and an increase in the price of the plasticiser of e.g. 30% will result in a material price increase of 10% for the plastic material. Prices of chemicals (and other industrial products) tend to decrease as production capacity and competition is increased. Different chemicals are however based on different raw materials and more or less complex and resource demanding chemical synthesis technologies. This of course sets limits to the minimum prices attainable even in a mature market, and some of the alternative plasticisers described may likely remain at higher price levels. It should be noted that the prices of DEHP have dropped significantly over the last ten year or more; probably due to the reduced demand driven by the regulation. Besides the price of the plasticisers, the substitution of the phthalates may imply some costs of research and development and process changes which have not been assessed in this study. Assessment of alternative flexible polymers A number of flexible polymers are available which can substitute for many traditional uses of flexible PVC. Polyethylene (PE), polyolefin elastomers, different polyurethane (PU) qualities, ethylene vinyl acetate (EVA) and different rubber types are examples among others. For many flexible PVC uses, also other substitute materials than flexible polymers exist. The existing LCA-based, application-focused assessments are few, and often the studies could not make clear-cut conclusions. But many materials exist with seemingly equal or better environmental, health and safety, performance and cost profiles. The assessment made here does not allow for a more detailed analysis of possibilities and limitations in the use of alternative flexible polymers. Environmental and health assessment A summary of the inherent properties for the investigated alternative plasticisers is shown in Table 0.4 using key parameters: acute and local effects, sensitisation, carcinogenicity, mutagenicity, reproductive toxicity, persistence, bioaccumulation and aquatic toxicity. From the overview it can be seen that all ten substances are expected to have low acute toxicity based on animal studies. With regard to local effects most substances are non-irritating to skin and eyes or only produce slight irritation which would not lead to classification. None of the tested substances are sensitising. Effects from repeated dose toxicity studies mainly include reduced body weight gain, increased organ weights (liver and/or kidney) and for some substance also changes in clinical chemistry or clinical pathology parameters. However, more serious pathological effects were not observed. Studies to evaluate the potential for reproductive/developmental toxicity primarily show toxic effects on parents and offspring. For TXIB statistically significant reproductive and developmental toxicity is observed. Click here to see: Table 0.4 Overview of main toxicological and ecotoxicological properties Carcinogenicity has only been evaluated for three substances in combined studies. For all three substances the outcome was negative (no carcinogenicity effect). However, the studies cannot be considered sufficient to exclude possible carcinogenic effects. The assessment in this study of the toxic properties of ATCB, COMGHA, DINCH and DEHT is in line with the recent assessment from the Scientific Committee on Emerging and Newly-Identified Health Risks (SCENIHR). All substances have been tested for acute toxicity for at least one exposure route, sensitisation (except ASE), subchronic toxicity and mutagenicity. All substances except ASE, COMGHA and DINA have been tested for both reproductive and developmental toxicity. With regard to carcinogenicity only ATBC, DEHT and DINCH have been tested in combined chronic toxicity and carcinogenicity studies. For DEGD, DGD and DEHT estrogenic activity has been tested in a uterotrophic assay without positive response. Most data used for the evaluation are considered of good quality, i.e. studies following accepted guidelines (OECD or US EPA) or studies considered acceptable at the time they were carried out. For some of the studies little information is available to evaluate the quality. However, key information is obtained from IUCLID data sheets, USEPA or OECD HPV robust summaries.). With regard to environmental properties, none of the 10 studied alternatives meet the criteria for being a PBT or vPvB substance, although all substances except GTA show one or two of these properties. GTA (triacetin) appears to be easily biodegradable, it does not bioaccumulate and has very moderate toxicity in the aquatic environment. DEGD, DGD and DINA also come out rather favourable, while ATBC and COMGHA come out negatively despite their degradability because of their aquatic toxicities and bioaccumulative properties. ASE and DINCH both have low acute toxicities to aquatic organisms, but are not easily degradable and have high log KOW values. DEHT is also not easily biodegradable and is bioaccumulative but its aquatic toxicity cannot be fully evaluated based on the data available. Useful fate data regarding biodegradability (in water) and bioaccumulative properties (either as BCF or log KOW) are available for all alternatives while other fate data are incomplete for some substances. With regard to ecotoxicological effect data, results from short-term tests with the base-set of organisms - fish, crustaceans and algae - exist for all 10 substances although the duration of some studies deviate from the current OECD standard. Overall, the data indentified are of good quality i.e. they are mostly based on studies performed according to accepted guideline procedures, and the studies have been evaluated to be reliable without restrictions or reliable with restrictions (e.g. in the USEPA HPV robust summaries).
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