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EDIPTEX - Environmental assessment of textiles

Annex 7: Management of chemicals in UMIPTEX

• General information on management of chemicals in lifecycle assessment
  • Assessment of chemicals in matrix lifecycle assessment
  • Principles of the assessment
  • Occurrence on lists
  • Danger classification
  • Procedure
• Assessment of chemical substances in the EDIP model
  • Method
  • Normalisation
  • Weighting
• Pesticides
• List of references for calculation of equivalency factors

When the EDIP PC tool and associated database are used for calculation of the overall statement for a product system, it is possible to calculate the overall potential impact on the different environmental impact categories at the same time. This calculation follows a common principle for all environmental impact categories. The specific contribution to the environmental impact potential is determined in the form of an equivalency factor for each substance being emitted or discharged during the course of the lifecycle and for each environmental impact category. This equivalency factor is expressed in the same unit for all substances so that it is possible to add them up. When this specific equivalency factor is multiplied by the amount of substance emitted or discharged, the substance's contribution to the environmental impact potential is obtained. When all these contributions are added up, one single impact potential for the environmental impact category is obtained.

General information on management of chemicals in lifecycle assessment

Most impact categories in lifecycle assessment are only affected by a limited number of chemicals. This applies to greenhouse effect, stratospheric ozone depletion, acidification, nutrient loading and photochemical ozone formation. The chemicals and groups of chemicals that contribute to these impact categories are listed in the EDIP method book (Wenzel et al., 1996). The calculation of the functional unit's overall impact on these impact categories is carried out automatically by the EDIP PC tool.

For several reasons, the impact categories ecotoxicity and human toxicity constitute a special challenge. In principle, all chemicals are toxic if exposure is sufficiently high. Therefore, the group of chemical substances that contributes to these impact categories is not limited. Moreover, no one single, well-defined impact mechanism forms the basis for toxic impacts. This is a large group of different basic impact mechanisms that all have the characteristic that they can lead to toxic impacts on ecosystems or humans.

Toxic impacts and assessment of them in lifecycle assessment will be in focus in the following sections. The first section describes how chemicals are handled in a more or less qualitative "matrix lifecycle assessment". The subsequent section describes how chemicals are assessed and how their impact potential is calculated in the quantitative EDIP model and in the EDIP PC tool.

Chemicals are assessed in a more or less stepwise approach, depending on the depth of the lifecycle assessment (matrix - detailed).

In the first step, where an overview of the products' environmental impacts during the lifecycle is created by means of a matrix lifecycle assessment, time does not reasonably permit in-depth chemical assessment. On the basis of the information available, an overview is generated of whether the product's lifecycle involves chemicals that authorities already regard as hazardous.

The next step depends on the current need. Are large amounts of specific chemicals being used or discharged that ought to be studied further, or are there other parameters during the product's lifecycle that should be in focus?

Then, the product's lifecycle is modelled in more detail. Equivalency factors already exist for a number of commonly occurring emissions and for emissions that were assessed in connection with previous EDIP projects. However, equivalency factors have not been calculated for a wide range of emissions. If these emissions are to contribute to the product's total contribution to the impact categories as regards toxic impacts, equivalency factors for the substances need to be calculated. These equivalency factors must be entered in the PC tool. The calculation of equivalency factors should be carried out by experts, but the principles are briefly reviewed in a subsequent section.

Assessment of chemicals in matrix lifecycle assessment

Chemicals in the lifecycle assessment matrix include chemicals used in production, as either raw materials or auxiliary materials, as well as discharges into air, water and possibly soil. The primary purpose of assessment of the chemicals in the matrix is to ensure that no significant environmental and health impacts are overlooked. Many of the chemicals are used in production and will probably primarily cause risks in relation to occupational health and safety. Occupational health and safety is currently not a routine part of the lifecycle assessment. Therefore, it is possible that the matrix will include chemicals that do not appear in the subsequent more detailed modelling of the lifecycle in a PC tool. However, the inclusion of chemicals in the matrix facilitates a qualitative assessment of the use of chemicals during the lifecycle, i.e. it makes it possible to assess whether the potential problems caused by the use of the chemicals have been addressed. If, for example, large amounts of solvents are used, have the appropriate health and safety considerations been taken, and can this been seen from the enterprise's emissions - or are there effective recovery and/or cleaning systems?

Principles of the assessment

At least 20,000 different chemical substances are being used in Denmark (Bro-Rasmussen et al., 1996), and they are all different as to their harmful properties for the environment and health. Therefore, it does not make sense to enter all chemicals that occur during the lifecycle of the studied product in the lifecycle assessment matrix. Firstly, such a list would not contribute to the assessment, as many substances are relatively harmless, and secondly, it would become difficult to assess. It is necessary to make a preliminary assessment of whether the substances have special harmful impacts on the environment or health. Two principles are applied to make such an assessment:

1.       Whether the substances are included on lists of substances that are harmful to health and the environment.

2.       Whether the products/auxiliary substances are danger-labelled with specific risk indications (R phrases).

Moreover, it should be considered whether large amounts of chemicals are used that do not appear on these lists, but which may constitute a problem due to the large amounts used.

Occurrence on lists

Lists of substances that are considered harmful to the environment and/or health have already been made.

The List of Undesirable Substances and the List of Effects

The Danish EPA has prepared a list of substances that are undesirable in products because of their impact on humans and/or the environment. This List of Effects forms the basis of the List of Undesirable Substances and contains approx. 1,100 substances. The List of Undesirable Substances contains approx. 100 substances, selected from the List of Effects because they are used in large volumes. This list represents substances the use of which Danish authorities wish to limit.

The List of Undesirable Substances and the Danish EPA's Advisory List for Self-classification of Dangerous Substances

The EU list of hazardous substances follows criteria laid down for classification of hazardous substances. Substances classified as hazardous to health and/or the environment should be included in the lifecycle assessment matrix. The Danish EPA has also prepared a list with guideline danger classifications for approx. 20,000 substances. This list was prepared on the basis of estimated effects, calculated on the basis of structural similarities between the substances.

Lists of substances that are regarded as harmful to health at work

The Danish Working Environment Authority and the National Institute of Occupational Health regularly assess the harmful impacts on health of various substances. There has been special focus on substances that are potentially carcinogenic, that may cause damage to the nervous system, and that may impair fertility. Substances that are assessed to be harmful to health and that should be included in the lifecycle assessment matrix are included in the following lists:

Cancer:

List of substances considered carcinogenic. WEA-GUIDE C.0.1, October 2000. [All substances on this list are included].

Damage to reproduction:

Reproduktionsskadende kemiske stoffer i arbejdsmiljøet (chemical substances at work that are harmful to reproduction). NIOH report no. 35/1991 (only available in Danish). [Substances with "extensive and limited evidence" have been included, i.e. substances from groups 1 and 2].

Damage to the nervous system:

Nervesystemskadende stoffer i arbejdsmiljøet - en kortlægning (survey of substances at work that are harmful to the nervous system). WEA report no. 13/1990 (only available in Danish). [Substances from groups 3, 4 and 5 have been included].

Occupational neurotoxicity. Evaluation of neurotoxicity data for selected chemicals. Nordic Council of Ministers. Danish Working Environment Authority. National Institute of Occupational Health, 1995. [Substances in groups 1, 2A, 2B and 3 have been included].

Lists of substances that are assessed to be harmful to the environment and health when discharged into the environment

A number of substances potentially have harmful impacts on the environment and health when discharged into the environment. Therefore, limit values have either been set for them or it has been decided that they should be given special priority when discharges are assessed. This applies to the substances on the following lists:

Air emissions

The Danish EPA's table of B values. 1997.

Wastewater

VKI - Institute for the Water Environment draft guidelines on connection of industrial wastewater to public wastewater treatment plants. Draft Danish EPA guidelines.

EU list 1 (Directive 76/464/EEC)

Bro-Rasmussen et al., 1994: EEC Water Quality Objectives for Chemicals Dangerous to Aquatic Environment (List 1). Reviews of Environmental Contamination and Toxicology, Vol 137, 1994.

Danger classification

Enterprises will often experience that they do not know the composition of the products/auxiliary substances used in production. In such situations, it is obviously not possible to assess whether there are substances that should be included in the lifecycle assessment matrix. However, products with a specified percentage content of hazardous substances must be classified and labelled with risk and safety phrases according to current regulations.

Table 7.1: Risk phrases that mean the product/chemical substance should be mentioned in the lifecycle assessment matrix

Several screening methods apply the classification criteria to prioritise substances, and one is EDIP (Hauschild, 1996). In this connection, we have applied the criteria of the EDIP screening method as our basis. R-phrases that result in an impact score of 4 or more in the EDIP screening method are shown in table 7.1, and a few newer R-phrases have been included. Thus, if the product is labelled with one or more of the R-phrases mentioned in table 7.1, they should be included in the lifecycle assessment matrix.

Procedure

A list must be prepared with all chemicals used and known discharges. Volumes used should be included as far as possible, and it should be noted whether it is a discharge or a substance used in production. If products are used and their composition is unknown, the products' danger labelling should be noted. On the basis of this list, chemicals and discharges are divided into three categories:

• Category 1 includes substances on the Danish EPA list of undesirable substances.
• Category 2 includes all other substances on the overall list as well as products that are labelled with one or more of the R-phrases mentioned above.
• Category 3 includes all other substances. Category 3 substances are not included in the lifecycle assessment matrix.

Thus, the lifecycle assessment matrix includes, at best, a complete list of category 1 and 2 substances. If it turns out to be impossible to obtain information about used/discharged volumes, a number of substances will be included from both category 1 and 2.

Assessment of chemical substances in the EDIP model

For environmental impact categories other than toxic impacts, it has been possible and expedient to express the potential environmental impact of each emission in relation to a reference substance, i.e. how much more, or less, the specific substance contributes compared to the reference. Thus, the impact potential for greenhouse effect is expressed as CO2 equivalents. As regards toxic impacts where there are many different impact mechanisms, it is hard to compare all substances to one reference substance, as the impact mechanisms for the specific substance and the reference substance may differ. Put simply, we have therefore decided to express the equivalency factor of a substance for toxic impacts as the amount of soil, water or air needed if 1 g of the substance is to be diluted enough so as not to have toxic impacts.

The substances for which there are no equivalency factors in the EDIP PC tool do not contribute to the assessment of the lifecycle's overall impact on the impact categories ecotoxicity and human toxicity. Therefore, it is necessary to calculate equivalency factors for the substance's contribution to these impact categories, particularly if the substance occurs in category 1 or 2 in the matrix lifecycle assessment. The following sections describe how the equivalency factors are calculated (and how the equivalency factors that are already in the EDIP PC tool are calculated).

It is important to note that, until now, the method has only been operationalised for discharges into the environment, i.e. toxic impacts on humans during use of the product, including occupational health and safety, and indoor climate are not being assessed in this method.

Method

The method for calculation of equivalency factors for toxicity and ecotoxicity is based on the substance's inherent properties and includes the fate of the chemical substance in the environment as well as its impacts on living organisms. The central properties of the substance in this connection are:

• Toxicity, ability to cause harmful impacts
• Persistence, ability to remain in the environment for a long time
• Bioaccumulation potential, ability to accumulate in living organisms and to be transmitted from one link in a food chain to the next (biomagnification). This also includes the substance's ability to accumulate in food for humans.

Figure 7.1 shows a schematic illustration of the fate and impact considerations behind the determination of equivalency factors

Figure 7.1: Determination of equivalency factors through fate and impact considerations – for translation of Danish terms see glossary in annex 11

The figure includes a number of parameters, which will be briefly explained in the following.

The distribution factor f_c is introduced in the calculations because a substance discharged into one sub-environment may contribute to toxicity in other sub-environments (e.g. air emission deposited on soil and water surfaces). Whether and how much a substance is redistributed depends on the substance's inherent properties as well as the environmental processes involved. The value for fc is between 0 and 1 and is based on information about the substance's half-life in air (t_½), Henry's law constant (H) (how easily the substance evaporates from water), and the relative percentage of soil and water surface in the area being considered.

The transport and transmission factor T is only applied in the equivalency factor for human toxicity. Tc is introduced to consider accumulation or dilution of the substance in the medium ingested by humans. For example, a substance that ends up in the sub-environment surface water may be accumulated in fish or shellfish, which may be eaten by humans at a later time. The bioconcentration factor BCF is used to describe how much of the chemical substance is accumulated in fish and shellfish.

The ingestion factor I_c shows values for the daily average ingestion of meat, milk, vegetable crops, fish and shellfish, water, soil and air. Average values for Denmark are used.

The biodegradability factor BIO shows how easily the substance is degraded in the environment. BIO can have the values 0.2, 0.5 or 1, corresponding to easily biodegradable, biodegradable and non-biodegradable. Substances are characterised using these designations when their biodegradability is studied according to OECD or EU guidelines.

The toxicity factor HTF shows the toxic impact of the substance on humans. The toxic impact is studied in animal test studies that attempt to determine which doses of the substance cause toxic impacts immediately (acute) or in long-term studies. Data from such studies are available in databases like RTECS (1999), HSDB (1999) and IRIS (1999). On the basis of such data and some fixed assessment factors, the daily dose (HRD or HRC) not expected to give long-tem toxic impacts in humans is determined. HTF is defined as the reciprocal of this value.

The ecotoxicity factor ETF shows the substance's toxic impact on organisms in the environment. Studies of the toxic impact are normally carried out on organisms that live in water (algae, crustaceans and fish) to determined which concentrations of the substance (in the water) cause toxic impacts. Data from such studies can be found in databases like AQUIRE (1992), RTECS (1999) and HSDB (1999). On the basis of such data and some fixed assessment factors, the concentration of the substance not expected to cause toxic impacts in the environment (PNEC) by acute and chronic exposure is determined. ETF is defined as the reciprocal of PNEC.

The bioconcentration factor BCF shows the substance's ability to accumulate in living organisms. This is normally determined by checking whether fish contain a higher concentration of the substance than the water in which the fish live. In general, the substance is bioconcentrated if the concentration in the fish is 100 times higher than in water. This ability is often connected to the fat solubility of the substance and can therefore be estimated on the basis of the substance's octanol-water partition coefficient (log Pow). As can be seen from the expression for the equivalency factor EF(et)c, the bioconcentration factor is normally not present. This is because, in long-term studies, fish are expected to accumulate the chemical substance and this means that bioconcentration has been included when the toxic impact is determined. If PNEC is determined on the basis of short-term studies, BCF should be included.

A great deal of physical and chemical data about the substance is needed, in order to determine the distribution factor, the transport and transmission factor and often also the bioconcentration factor. These data can often be found in the databases mentioned or be estimated from the substance's structural similarities to other substances (QSAR methods).

The above is an overall description of the procedure for determination of equivalency factors. A detailed description of calculations and assessment principles is in the EDIP method (Hauschild, 1996). Determination of equivalency factors requires expertise, and it is recommended that qualified consultants be contacted if relevant. Determination of equivalency factors takes an estimated average of 6-8 hours per substance.

When equivalency factors exist for all substances being discharged during the lifecycle of the product considered, the EDIP PC tool will calculate the overall impact of the product system on the environmental impact categories human toxicity and ecotoxicity. This is done by multiplying the volumes of chemicals being discharged by the relevant equivalency factor, and the impact on the environmental impact categories is stated as a number of m³ (can be interpreted as the number of m³ of soil, water or air the product system contaminates up to a No Observed Adverse Effect Level).

Normalisation

In the normalisation process, the product's total contribution to each impact type is related to the overall impact on this impact type. The overall impact on society is calculated and divided by the relevant number of people (for global impacts, the world's total population, and for regional and local impacts, Denmark's population). The result is the overall impact per person (person equivalent). The product's contribution can thus be presented as a number of person equivalents. Normalisation has three purposes:

• Comparison of environmental impact categories using person equivalents.
• Error check. The assessment can be reviewed with a view to checking calculations and statements, if the product contributes remarkably more to an impact type than others, or in relation to what is expected.
• Pure presentation technique. When the same unit is used, the impacts can be presented together.

Normalisation of toxic impacts is carried out on the basis of an estimate of discharges of toxic chemical substances in Denmark.

Weighting

Normalisation provides a uniform basis for comparison of all the environmental impact categories, because they are all related to the extent of the product system's impact compared with the overall impact. However, it may also be necessary to assess the environmental importance of the impact (what is worst; acidification or nutrient loading). This is a very tough assessment to make, and there is no conclusive answer. The EDIP method applies the politically determined targets for reduction of environmental impacts as an indication of the importance of the environmental impact. The normalised impact potentials are thus weighted using a factor that indicates the importance of the relevant environmental impact category in Danish and international policies. For toxic impacts, the weighting factor is the ratio between the toxic impact potential of the actual discharges in 1990 and the toxic impact potential of the target discharges in 2000.

Pesticides

Calculations of equivalency factors for ecotoxicity and human toxicity have been carried out in accordance with the EDIP method as described in Hauschild et al. (1998a) and Hauschild et al. (1998b).

The principles of the TGD (EC, 1996, part II appendix II) have been applied to estimate the fate of the substances in wastewater treatment plants (estimated distribution factors for wastewater treatment plants). In situations where the use of these principles, which are based on the SimpleTreat model, would be extensively flawed (e.g. for detergents where the fate cannot be based on log Kow), measured distribution values have been applied. These values have been found in scientific articles through literature searches.

Only log Kow values have been used for estimates of equivalency factors for human toxicity (as prescribed in EDIP), as hardly any relevant measured distribution factors exist. The estimated equivalency factors for human toxicity as regards amphiphile/polar substances (e.g. detergents) are thus subject to significantly more uncertainty than the remaining equivalency factors.

When estimating the fate of pesticides when e.g. a cotton field is sprayed, the principles of Hauschild (2000) have been applied with the modification that the amount of pesticides evaporating from the field is regarded as emission into air. In this way, the pesticide's half-life in the air is considered.

The data basis for the calculated equivalency factors primarily comes from "substance databases" and reference handbooks such as the database EUCLID (1996) and the handbook ”Nikunen” (Nikunen, 1990). For physical/chemical data, the SRC log P database (1999) and Howard (1989) have been used, and for ecotoxicology impact data, the database AQUIRE (1999) has been used. The sources RTECS (2000) and HSDB (2000) can be mentioned for human toxicological impacts.

The equivalency factors (in m³/g) calculated under EDIPTEX with associated relevant distribution factors for wastewater treatment plants (emission from wastewater treatment) and for spraying fields (emission from technosphere) can be found in the database.

List of references for calculation of equivalency factors

Nikunen, E., R. Leinonen & A. Kultamaa (1990). Environmental Properties of Chemicals. Ministry of Environment. Research Report 91. VAPK-Publ. Helsinki.

Howard, P.H. (1989). Handbook of Environmental Fate and Exposure Data For Organic Chemicals. Lewis Publ. Vol. I (1989), II (1990), III (1991), IV (1993).

AQUIRE (1999). Aquatic Toxicity Information Retrieval Database. EPA, United States Environmental Protection Agency. http://www.epa.gov/ecotox/.

IUCLID (1996). International Uniform Chemical Information Database. Existing chemicals. 1st ed. European Chemicals Bureau. Environment Institute, Ispra, Italy.

HSDB. (2000) Hazardous Substances Data Bank (HSDB®).Vers. 2000/03. National Library of Medicine (NLM ), USA. http://www.nlm.nih.gov/.

RTECS (2000). Registry of Toxic Effects of Chemical Substances, Vers. 2000/04

National Institute for Occupational Safety and Health (NIOSH), USA. CD-ROM: SilverPlatter International N.V.

HSDB (2000). Hazardous Substances Data Bank, Vers. 2000/03
National Library of Medicine (NLM), USA. CD-ROM: SilverPlatter International N.V.

Syracuse log P database (1999). Database accessed from the Internet. http://esc.syrres.com/cgi-bin/odbic.exe/~templates/kowtp.htm.

Hauschild M., Olsen S.I. and Wenzel H. (1998b). Human toxicity as a criterion in the environmental assessment of products. In: Environmental Assessment of Products: Volume 2: Scientific background, Hauschild M. and Wenzel H. (eds.), Chapman & Hall, pp. 314-443.

Hauschild M., Wenzel H., Damborg A. and Tørsløv J. (1998a). Ecotoxicity as a criterion in the environmental assessment of products. In: Environmental Assessment of Products: Volume 2: Scientific background, Hauschild M. and Wenzel H. (eds.), Chapman & Hall, pp. 203-314.

Hauschild, M. (2000). Estimating pesticide emissions for lifecycle assessment of agricultural products. From B.P. Weidema and M.J.G. Meeusen (eds.). Agricultural data for lifecycle assessments. Report No. 2.00.01, pp. 64-79. Agricultural Economics Research Institute (LEI), The Hague. ISBN 90-5242-563-9.

EC (1996). Technical guidance documents in support of commission directive 93/67/EEC on risk assessment for new notified substances and commission regulation (EC) No. 1488/94 on risk assessment for existing substances. Office for Official Publications of the European Community, Luxembourg.

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Version 1.0 July 2007, © Danish Environmental Protection Agency