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Inclusion of HBCDD, DEHP, BBP, DBP and additive use of TBBPA in annex IV of the Commission's recast proposal of the RoHS Directive

5 Butylbenzylphthalate (BBP)

5.1 Main concern

The main concern as to butylbenzylphthalate (BBP) is its possible effect on reproduction and possible long-term adverse effects in the aquatic environment.

BBP is (November 2009) included in the draft list of substances recommended by ECHA for inclusion in the list of substances subject to authorisation in Annex XIV of REACH.

BBP is included in Annex I to Regulation No 1272/2008 (CLP) with the classification Repr. Cat.2; R61: May cause harm to the unborn child, Repr. Cat.3; R62: Possible risk of impaired fertility (Symbol: T), R50-53: Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment (Symbol: N). DBP is on the EU list of substances with endocrine disruption classifications, classified in CAT. 1 “Evidence for endocrine disruption in living organisms” (BKH, 2000).

Due to the possible effect on reproduction the substance shall not be used as substances or as constituents of preparations, at concentrations of greater than 0.1 % by mass of the plasticised material, in toys and childcare articles (Regulation No 552/2009). Further, it is not permitted for use in cosmetics (Directive 2004/93/EC).

An EU Risk Assessment has been finalised for BBP (ECB, 2007). The EU Risk Assessment Report (RAR) concludes for workers, consumers and humans exposed through the environment that there is at present no need for further information and/or testing and for risk reduction measures beyond those which are being applied already. The RAR note in the summary that recent epidemiological studies support the hypothesis that prenatal phthalate exposure at environmental levels may affect male reproductive development in humans. However, due to small sample size in the studies, this issue will have to be further investigated, and new studies in the future should be taken into account in the risk assessment of BBP (ECB, 2007).

The review undertaken for the European Commission by Öko-institut e.V. as background for selection of candidate substances for a potential inclusion into the RoHS Directive (Gross et al., 2008) recommend BBP as a potential candidate.

5.2 Characterisation of the substance

BBP is a specialty plasticiser used in minor concentrations in some flexible PVC applications as well as in some non-polymer uses such as for example in paints, adhesives, sealants, printing inks, etc. (COWI, 2009a). Phthalate plasticisers are always used as so-called external plasticisers, meaning that they are not bound chemically in the polymer matrix. They can therefore migrate out of the plasticised polymer by extraction with soapy water, oils, etc., by evaporation and by diffusion, and thereby become available for exposure to humans via inhalation, skin and diet, as well at to the environment.

The structural formula for BBP (CAS. No 85-68-7) is shown below.

BBP

Illustration: BBP

The following information in this section is, if nothing else is mentioned, extracted from an assessment of the manufacturing and use of butyl benzyl phthalate (BBP) recently published by European Chemicals Agency (COWI, 2009a).

The total produced tonnage of BBP in 2007 in the EU was below 18,000 t/y. A significant part of the produced tonnage is exported to countries outside the EU. The market for BBP has been decreasing over the last decade. In the period 1994-1997, the total reported Western European production of BBP was 45,000 t/y whereas for 2004 a production volume of 19,500 t/y was reported.

More than 70% of the BBP was in 2007 used as a plasticiser in polymer products, mainly PVC for flooring. BBP is typically used together with other plasticisers e.g. DEHP or DINP, in concentrations of a few percent, in order to add special performance to the polymer during processing (faster gelation of the polymer) and in the end product (hardened, stain resistant surface to vinyl flooring). BBP has been used widely by the flooring industry to speed up production and adding surface properties to flooring materials.

The end-product uses of BBP are as follows:

  • Flooring (both calendered and spread coated flooring);
  • Wall covering;
  • Coating of leather and textiles (upholstery, shoe uppers, wallets/bags, luggage);
  • Packaging films;
  • Sealants (polysulphide based, polyurethane based or acrylic-based) for insulating double glazing and other applications;
  • Paints for car care and construction (acrylic lacquers and other);
  • Inks for paper and board;
  • Adhesives (polyvinyl acetate and other);
  • Miscellaneous (hard PVC, nitrile rubber and other).

The major application area flooring accounting for about 50% of the total consumption, while the second larges application area, polysulphide sealants account for about 19% of the total.

5.3 Applications in EEE

BBP usage in electrical and electronic equipment (EEE) has not been confirmed. Based on general background knowledge, BBP may however possibly be used in synthetic leather and coated textile in straps, flexible or rigid PVC sheet, sealants, printing inks and adhesives. BBP may in principle be used for these applications in products within all product types. The application of BBP in some of the other flexible polymers in EEE cannot be ruled out completely.

5.4 Quantities of the substance used

No estimates of BBP consumption in EEE have been found. Such estimates are hard to form due to lack of confirmation of BBP usage in EEE parts.

An estimated 8,000 tonnes of BBP is used annually for production in the EU, of which an estimated 3,840 t/y is used for flooring, and 560 t/ is used for calendered film. The remaining 3,600 t/y BBP is used for polysulfide and other sealants (1,520 t), imitated leather and textiles (800 t), hard PVC compounding (640 t), PVA and other adhesives (400 t), paints and inks (160 t), other uses (80) (COWI; 2009d). A minor share of this consumption may used in EEE parts; probably well below 10% considering the many other potential application areas. The consumption of BBP in EEE produced in the EU is therefore likely in the range of 20-200 t/y.

An additional, but unknown amount may be used in imported EEE and imported EEE parts.

5.5 Available alternatives

Today, the principal alternatives to BBP appear to be dibenzoates such as dipropylene glycol dibenzoate (DGD) and the mixed dibenzoates product Benzoflex 2088, which have been increasingly used in the vinyl flooring business (the main application of BBP). With adjustments of the polymer/plasticiser formulations, and in some cases processing adjustments, these alternative plasticisers are reported by producers to perform technically suitably as alternatives to BBP as specialty PVC plasticisers. Glycerol triacetate (GTA) may also be a technically suitable alternative for some (non-polymer) applications. There may also be other alternatives to BBP.

With its faster, lower temperature gelling characteristics compared to the general plasticiser DEHP, using alkylsulfonic phenylester (ASE) as primary plasticiser may reduce the need for adding a gelling aid like BBP. ASE is however currently somewhat more expensive than DEHP and DBP.

Another alternative to using BBP is to simply omit its use, and accept the potentially altered production characteristics such as slightly slower production of flexible PVC products or slightly increased energy input for gellation of the flexible polymer.

BBP is mentioned as a critical component in seals for insulating double glazing which is not relevant for EEE (BBP Information Centre, 2009), but it cannot be ruled out that there might be some particular difficulties in substituting the BBP for some niche applications of the substance in EEE.

5.6 Socioeconomic impacts

5.6.1 Substitution costs

The substitution costs will mainly fall at the processors and formulators of PVC and other potentially BBP containing materials such as sealants, glues, etc. For coatings and other integrated composite parts, the EEE manufacturers may act as PVC processors themselves, and may need to be involved in reformulation of the PVC plastisols or compounds used. The plasticiser producers will normally be involved in the substitution, because they act as advisors for the processors and formulators in the formulation of the polymer/plasticiser system. The alternative plasticisers are already developed and marketed, but costs for increasing the production volume may be implied. Costs for research in using alternatives for new applications will be furthered to the customers. One of the alternatives to using BBP is to simply omit its use. This may result in increased production time and thereby potentially increased production prices. All substitution costs are expected to ultimately be furthered to the end customers.

Table 5.1 shows price examples of BBP, DEHP and selected alternatives to BBP. As shown, DGD and Benzoflex 2088 had comparable or slightly higher prices per weight than DEHP, while GTA had a somewhat higher price per weight. Note that alternatives may not be used in the same amount as BBP to obtain the desired effect on the polymer; data are not available for a closer comparison. Many PVC products are sold in highly competitive markets, and PVC processing industry is sensitive to even minor price changes on raw materials (TURI, 2006).

Table 5.1
Examples of comparative prices of DEHP, BBP and selected alternatives (from COWI, 2009)

Substance Price, Relative price to
DEHP and BBP, %		 Remarks
DEHP (2006) 0.70 USD/Lb 100% TURI (2006)
BBP (2006) 0.70 USD/Lb 100% TURI (2006)
Benzoflex 2088   "Slightly higher" Genovique (2009)
DGD (2006) 0.73 USD/Lb 104% TURI (2006)
ASE (2009) 1,75 €/kg 175% *1 Lanxess (2009)
GTA €1,50/KG 150% *1 Lanxess (2009)

Notes: *1: DEHP € price in 2006-2009 ˜0.8-1€/kg; 1€ is used for calculations.

For most EEE, the parts which may contain BBP comprise only a minor fraction of the equipment/product and thus also only a minor part of the total production price of the product. If used at all for this equipment, BBP and alternatives are only used in small concentrations, further decreasing importance of the secondary plasticisers' price in this context. Also, considerable fractions of the flexible PVC and other materials used in EEE may already be formulated with other specialty plasticisers instead of BBP. Increases in consumer prices for EEE as a result of a restriction of BBP use in EEE are therefore expected to be minimal or even negligible.

5.6.2 Impacts on supply chain

SMEs
The considerations regarding impacts on SMEs are the same as for DEHP, and reference is made to section 3.3.

EU production
BBP, ASE and GTA are examples of plasticisers produced by relatively large or multinational European based companies. DGD and Benzoflex 2088 are currently produced in the USA.

Production of EEE is substantial in the EU, however a large part of the total end-user consumption of EEE is imported as finished goods from outside the EU. This is notably the case for small household appliances, consumer electronics, IT equipment, and toys etc., but also for other EEE groups.

For EU based EEE producers, BBP containing parts may be produced by themselves or by subcontracting PVC processing or non-polymer formulator companies in the EU as well as on the world market.

Differences in restriction of the use of the substance via the RoHS Directive or via REACH are discussed in section 1.3.

5.6.3 Impacts on waste management

The considerations regarding waste management are the same as for DBP.

5.6.4 Administrative costs

The considerations regarding administrative are the same as for DBP.

5.7 Impacts on health and environment

5.7.1 Impact profile of substance and alternatives

Environmental and health properties of alternatives to DEHP, DBP and BBP have been reviewed for ECHA (COWI, 2009a,b,c) as part of the evaluation of substances for inclusion of substances on the candidate list of SVHC for authorisation. These substances and other alternatives have further recently been reviewed in a study for the Danish EPA (Maag et al., 2009).

Study for the Danish EPA on environmental and health properties of alternatives to DEHP, DBP and BBP
The results of the study as regards environmental and human health properties are summarised in Table 3.4 in section 3.7.1. Data for DEHP, BBP and DBP, based on data in the Risk Assessment of each substance is summarized in the table using the same notation on the basis of data from the EU risk assessments. The table includes substances that are mainly alternatives to DBP or BBP, but as the substitution is typically not a one-to-one substitution, but often is a replacement of one plasticiser system (e.g. with DEHP as primary and DBP or BBP as secondary plasticiser) with another system (with more substances together), it is convenient to keep the information on all the substances together in one table.

The results from the study indicate that a number of alternatives to BBP exist which may potentially be less problematic than BBP with regard to human health effects. However, for most of these substances data are missing for critical endpoints, in particular for carcinogenicity, where tests are only available for 3 out of 10 potential alternatives. Compared to BBP and based on the available studies, the alternatives appear to be less toxic than BBP. Like BBP, all except GTA, have some effects on body weight, liver or kidney in repeated dose toxicity studies. With regard to reproductive toxicity, 3 of the 10 studied alternatives have some indication of developmental effects at comparable levels to NOAEL for fertility for BBP. For 3 alternatives carcinogenicity is studied in combined chronic toxicity/carcinogenicity studies with negative outcome. Only one study was a guideline study.

With regard to environmental effects of the alternatives, 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 quite variable and incomplete. 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.

None of the alternatives are considered PBT or vPvB substances. One of the 10 studied substances( GTA) did not show any aquatic toxicity and is also not considered persistent or bioaccumulative whereas the other substances show positive results in one or more of these areas. From an environmental point of view only few of the alternatives (DEGD, DINA, GTA) stand out as less problematic compared to BBP based on the overall assessment presented in Table 3.4.

5.8 Conclusions for BBP

The main concern as to BBP is the substance’s possible effect on reproduction and possible long-term adverse effects in the aquatic environment.

According to the EU Risk Assessment Report, BBP is bioaccumulative and toxic to aquatic organisms but not persistent in the environment. BBP is therefore not considered a PBT substance or a vPvB substance. With regard to CMR effects the RAR concludes based on the available studies that BBP is considered non-genotoxic and also non-carcinogenic. BBP raises concern because of reproductive toxicity. In conclusion, BBP is found to adversely affect the reproductive organs in experimental animal studies which may affect fertility. Furthermore the substance is found to be a developmental toxicant and to possess anti-androgen like properties in experimental animal studies.

It has not been possible to fully confirm that BBP is currently used in the manufacture of EEE. The consumption of BBP for EEE production in the EU is likely in the range of 20-200 t/y; the BBP may be used in flexible or rigid PVC, sheets, adhesives, sealants and other non-polymer applications. The plasticiser may be present in a low percentage of products within all product categories.

The possible use of BBP in EEE is not deemed essential as technically suitable alternatives are available and already used today with a reservation for some specific non-polymer applications where substitution may be particular difficult (not identified). All available data indicate that alternatives exist, for example DGD and Benzoflex 2088. For PVC plasticisation, omitting the use of a fast gelling secondary plasticiser as BBP may also be technically possible, although probably with increased PVC processing expenses as a consequence.

Costs - For most EEE, the parts which may contain BBP comprise only a minor fraction of the equipment/product and thus also only a minor part of the total production price of the product. Price difference between the substance and alternatives is approximately the same as for DEHP. As the consumption of the substance is only about one percent of the consumption of DEHP the increases in consumer prices for EEE, as a result of a restriction on the use of BBP in EEE, are therefore expected to be minimal.

BBP is typically used in plastic components where other RoHS substances have traditionally been used as well in pigments and stabilisers; however these can be determined by a XRF screening. The phthalates are typically used in other plastic parts than the brominated flame retardants. The main extra administrative costs are estimated to be related to compliance control, where the extra costs would comprise the costs of sample preparation and analysis. The price of analysis for DEHP, DBP and BBP is nearly the same as for analysis of DEHP only.

The scattered use of DBP in non-polymer applications in EEE may result in relatively high costs of compliance control as relatively many samples have to be taken. For non-polymer applications compliance control will be particular difficult and will imply control of materials not otherwise controlled for other RoHS substances.

Benefits - Available data for the alternatives indicate that with regard to human health effects less problematic alternatives exist. This conclusion is primarily based on data for repeated dose toxicity and existing reproductive toxicity data. However, most of these alternatives are not fully investigated with regard to reproductive toxicity and in particular with regard to carcinogenicity.

As for the environmental assessment of the alternatives the picture is not as clear, but three substances seem at least to be less problematic compared to BBP and these are DEGD, DINA, and GTA.

 

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Version 1.0 March 2010, © Danish Environmental Protection Agency