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Handbook on environmental assessment of products

5. Carry out an extended chemical assessment

The preliminary environmental assessment may show that the environmental and health-related impacts from the product are mainly associated with one particular phase, or that special issues overshadow the other environmental impacts. Examples would be working-environment problems in connection with production or emissions of chemicals during use of the product.

This chapter focuses on one such situation: use of chemicals. It will provide you with an overview of what you can do if your product contains many chemicals that end up in the environment. Emphasis is placed on how you assess whether the emission of chemicals is the most important aspect of the product’s environmental impact. The chapter presents criteria which you can use to carry out this assessment. You will also gain insights into what you yourself can do; for example, you can find data on the chemical contents of your product.

5.1 Expand the chemical assessment

First of all, it is important to determine when chemicals are so significant that the main focus should be on assessing them, either instead of an LCA or as a supplement to an LCA.

As we were preparing this Handbook, we looked at two examples where the products being assessed were cleaning agents and dyes. After a preliminary environmental assessment, it was decided that the chemicals were so important to the environmental impact that a chemical assessment should be carried out instead of an LCA.

The examples did not give rise to much doubt, partly because the products consisted of chemicals which are emitted 100% to the environment after use, partly because they belonged to product groups (cleaning agents and surface-active substances) where previous LCAs have demonstrated that their most significant impacts occur during the disposal phase. It can be more difficult to carry out this assessment in other cases. Chapter 3, sections 3.2.4 and 3.3 contain more detailed descriptions of what criteria you should apply in this assessment.

Often, it will not be relevant to carry out an actual chemical assessment of substances which are used by subcontractors because the quantities are relatively small. If it is relevant after all, this will be apparent from the detailed LCA.

As illustrated in figure 2.2 in section A, the process used in the simplified LCA stresses that you should work with a colleague, a consultant, or similar to discuss your options on the basis of the data collected before making your final choices. When you need to choose whether to carry out chemical assessment, it is important that you enter into such dialogue.

5.1.1 Screening for harmful impacts on health and the environment

In the preliminary environmental assessment (the MECO chart), you established an initial overview of the chemicals in the product. You can now use this overview as a basis for screening the chemicals for dangerous properties, so that you focus your efforts on the most significant chemicals.

When you prepared the MECO chart, you identified the chemicals featured on various lists - i.e. the chemicals which are regarded as particularly dangerous. The screening makes it possible for you to assign priorities and to determine which chemicals have the most harmful properties – i.e. which chemicals should be subjected to more detailed assessment.

It may, however, be necessary to assess other chemicals, e.g. because they are used in large quantities in the product or because they have harmful properties which are not identified in the lists. In the example with the cleaning agent, there was a desire to assess the product in relation to the criteria for the Swan Label. Thus, it was necessary to assess surface-active substances which are not included in the lists, but which may be harmful to aquatic organisms, because this is part of the criteria for the Swan Label.

The results of a screening should include an identification of the following issues:

	What substances are dangerous?
	In what quantities do they appear?
	What are the risks of human beings or the environment being exposed to the substances?

The interpretation of the MECO chart saw the introduction of a qualitative method which is based on the initial classification of the chemicals into type 1, 2 or 3.

Here, we present a semi-quantitative method for carrying out this screening. We have chosen to recommend the EDIP screening method, developed as part of the project "Environmental Design of Industrial Products" [Wenzel et al, 1996].

Other methods are, however, available, e.g. MUP [Schmidt et al, 1994] and UPH [the Danish Technological Institute, et al, 1996]. In some cases, it may be advantageous to use these methods – for example if you have prior knowledge of them.

5.1.2 The EDIP screening method

The EDIP screening method is described in detail in the method description of the EDIP method [Hauschild, M., 1996], but will be briefly summarised here.

The EDIP screening method has been developed to look at harmful impacts on health and the environment, and the EU’s danger classification of chemical substances has been used as the point of departure [the List of Dangerous Substances]. This danger classification is supplemented by other lists as regards impacts on health. Specifically, the Danish Working Environment Agency lists of carcinogenic and allergenic substances are used, as are their lists of substances which damage reproduction or the nervous system. However, not many companies have these lists on their bookshelves, and the information is not available on the Internet. Consequently, these lists have been omitted. The List of Undesirable Substances and the Impact List have both, however, been included in the screening method.

The method looks at the possibility of human beings and/or the environment becoming exposed to the relevant chemical (exposure) and the harmful effect of the chemical, if any (impact). This is done by assigning scores for exposure and impact, respectively.

The score for exposure is partly based on whether the substance is emitted or not, and partly on whether the substance can be expected to stay in the environment because it is not degraded (non-biodegradable) or is expected to accumulate in living organisms (bioaccumulating).

The score for impact is a measure of the toxicity of a substance if human beings and/or the environment are exposed to it.

The total score is arrived at by multiplying the two scores. The two figures are multiplied because the toxicity of a given substance is regarded as having greater impact on the environment if the substance is emitted regularly, is non-biodegradable or is bioaccumulated.

5.1.2.1 EDIP exposure score

The score for exposure is a combination of the expected emissions (yes/no) and the possibility of undesirable long-term impacts on the environment.

From the classification of chemical substances, these two risk phrases can be used:

R 53: May cause long-term adverse effects in the aquatic environment.

R 58: May cause long-term adverse effects in the environment

These R phrases were developed to classify the degree of danger to the environment, but are also relevant to human beings in our capacity as organisms within the ecosystems. The two R phrases listed above are assigned to substances within the List of Dangerous Substances when the substance is difficult to degrade and/or is accumulated in fat tissue. The score for exposure is shown in table 5.1.

Table 5.1
Exposure score. The two scores are summed up and are subsequently multiplied with toxicity scores. If both exposure values are 0 (total exposure score = 0), the toxicity score is multiplied by 1 instead of 0.

If the substance in question is not included in the List of Dangerous Substances, you will have to assess the risk of undesirable long-term effects yourself. This can be done by means of the parameter logPOW, which stands for the distribution coefficient for octanole-water (or logKOW). Among other things, this parameter indicates whether the substance will be accumulated in fat tissue.

If you know the CAS no. of the substance, you can try to find the logPOW on the internet at http://esc_plaza.syrres.com/interkow/kowdemo.htm, where you can also find calculated values. You can also find the logPOW on other websites, e.g. at chemfinder (http://www.chemfinder.com) or HSDB (http://sis.nlm.nih.gov/cgi-bin/sis/htmlgen?HSDB).

5.1.2.2 Eco-toxicity score

As regards toxicity towards organisms which live in the environment – the so-called eco-toxicity – a distinction is made between toxicity towards organisms in water (aquatic eco-toxicity) and toxicity towards organisms in soil (terrestrial eco-toxicity). This is why a score is given for each of these. The total score for eco-toxicity is established by combining the toxicity towards aquatic organisms (R50-R52 either alone or in combination with other R phrases) and the toxicity towards terrestrial organisms (R54-R57 either alone or in combination with other R phrases). The two scores are added to form a total score for the danger posed to the environment. Criteria and score values can be found in table 5.2.

Table 5.2
Scoring for eco-toxicity. The two scores are added up and are subsequently multiplied with the score for exposure.

If you suspect that a non-labelled substance should be labelled with one of the R phrases for danger to the environment, you should have the properties of that substance examined in relation to the criteria for classification of the danger to the environment. Many substances have not been assessed and classified in accordance with these criteria. If you do not have detailed knowledge about how to go about this task, you should consult with experts.

If a substance is listed in the List of Undesirable Substances or the Impact List, use an eco-toxicity score of 8.

If no eco-toxicity data are available for the substance, apply an eco-toxicity score of 8 (4 for the aquatic environment and 4 for the terrestrial environment. If, however, the substance is well-known and is regarded as having no significant harmful effects (e.g. water or salt), apply a score of 0.

Table 5.3
The total score for danger to the environment is established by multiplying the score for exposure and the score for toxicity

5.1.2.4 Score for human toxicity

Generally speaking, we have much greater experience with and knowledge about various types of impact on human beings than on organisms within the environment. Naturally, the scoring system reflects this fact. This means that the chart for assigning scores for toxicity towards human beings is more nuanced and detailed than the corresponding chart for the danger to the environment.

Scores are allocated on the basis of the relevant danger classification for health and R phrases (from the List of Dangerous Substances). The chart with criteria for allocating scores is shown in table 5.4.

If the substance appears in the List of Undesirable Substances, assign a score of 8 to it. If it is included in the Impact list, assign a score of 4.

Many substances have not been assessed and classified in accordance with these criteria. Therefore, the same applies here as for danger to the environment: if you suspect that a non-labelled substance should be labelled with one of the R phrases for danger to health, you should have the properties of that substance examined in relation to the criteria for danger classification. If you do not have detailed knowledge about how to go about this task, ask the experts.

Table 5.4
Score for human toxicity. The table shows the criteria for allocation into categories on the basis of the List of Dangerous Substances. The score for a given substance will be the highest score reached by it in this chart.

5.1.2.5 Total score for danger to health

Table 5.6
The total score for the danger to health is established by multiplying the scores for exposure and toxicity

5.1.2.6 Carrying out the screening

It will be easy for you to find much of the information for the screening yourself, but we recommend that you seek help to carry out assessments of substances which are not featured in any lists. This is recommended because such work often involve estimates that require a thorough knowledge of chemical assessment.

When you have found the relevant information, screening is carried out as illustrated above and in examples B5.2-5. Substances with a score of 16 or more should be assessed in greater detail. You should also decide whether some substances are used in such quantities that they should also be assessed in greater detail despite a lower score – for example if a given substance accounts for 50 per cent of the product.

5.1.3 Detailed assessment of chemical substances with high scores

Now you have identified the substances which should be assessed in greater detail. To do so, you will have to obtain information which demonstrates how dangerous the chemical substances are, and what the chances are of people and the environment becoming exposed to the substances.

Unless you already have detailed knowledge of how to carry out such assessment, you should seek expert advice for this task.

5.2 Interpreting the chemical assessment

The screening of the chemicals can primarily be used to assign priorities to any substances that need more detailed assessment. The scores can also to some extent be used directly if you combine them with data about the quantities used of the relevant substances. You should, however, be aware that the uncertainty associated with the assessment is greater for scores than for detailed assessments. Consequently, scores cannot be used to support decisions with the same weight as detailed chemical assessments.

Once you have found data on the chemical substances in the product, it can be assessed whether use of the chemical substances entails a risk of harmful effects. As was mentioned above, it is particularly important to assess what harmful impacts the substances may have, in which situations human beings and/or the environment can be exposed to the chemical substances, and in what quantities. Unless you already know exactly how to assess and interpret such data, we recommend that you look to relevant experts for assistance.

The danger posed by the substances is assessed on the basis of their potential harmful impacts and the doses necessary to produce such impacts.

Exposure to the substances is assessed on the basis of the substances’ physical and chemical data, and on the basis of knowledge/data about patterns of use in the relevant situation (is the substance discharged along with wastewater? Is it vented into air via ventilation? etc.). As the quantities used are also assessed at the same time, it is possible to assess the level of exposure for human beings and/or the environment with greater accuracy.

On this basis, it is possible to assess the risk of human beings and/or the environment becoming exposed to the chemical substances to such a degree that harmful impacts may occur.

The interpretation of this assessment depends somewhat on the overall objective. If, for example, two products are being compared, it would be relevant to assess which of the products poses the least risk of harmful impacts. If the objective is to bring about environmental improvements to a single product, it would be relevant to identify the chemical substances for which substitutes might be found.

There will be quite a lot of uncertainty associated with such an assessment, partly about the level of exposure for human beings and/ or the environment, and partly about the toxicity of the substance. It is rarely possible to indicate the level of uncertainty with much precision, but it is important to be aware where uncertainties exist in the assessment.

5.3 Did you get answers to your questions?

Does the assessment you have carried out provide a sufficient basis for extracting answers and making decisions? Or is it necessary to proceed with further data collection and/or assessment? The answer to this question depends partly on the goal defined for the assessment, and partly on the importance of the decisions to be made.

It may, for example, be necessary to proceed if the assessment shows that there is a risk of harmful impacts, or if the data basis is uncertain. If, however, you find that the doses which human beings and/or the environment can be exposed to are much smaller (by a factor of several sizes) than the doses which cause harmful effects, there is no reason to carry out additional work.

If the assessment is actually a comparison, the results are only satisfactory if the assessments of all alternatives are on par with each other.

Is the assessment satisfactory?

	Have you obtained information about all relevant chemical substances?
	Do you know enough about the use of the chemical substances to be able to assess the exposure?
	What uncertainties are there? And how great are they?
	Seek export assistance for an actual risk assessment of chemicals.

Example B5.6: Varnishes The substances which scored high scores in examples B5.2-5 –Bisphenol A diglycidylether and Neodecanoic acid, oxiranylmethyl ester – have been assessed in greater detail. The bisphenol is highly allergenic. It is particularly dangerous to health during manufacture, i.e. within the working environment, as it hardens relatively quickly and so ceases to be a health hazard after that time. If the substance is to be used, special attention should be paid to working-environment issues. It was not possible to find further information about neodecanoic acid, oxiranylmethyl ester in the most commonly used databases. Additional work should be carried out to ensure a better assessment of the possibilities of exposure. If it turns out that the substance entails great risk of exposure, research of the available literature should be carried out to find more information.

5.4 Find additional data

By now, you have decided – possibly with assistance from colleagues and/or experts – whether the present assessment basis is sufficient for your purposes. You now need to determine what the assessment should be supplemented by: what data do you need to support your conclusions? And which are the weakest links in your assessment?

If you yourself had the background knowledge necessary to carry out these assessments, you should now consider whether it is time to involve experts/consultants. Such experts can often provide more in-depth knowledge and have access to further data.

It may also be that there is a need to seek information from relevant suppliers of chemicals, or to examine the incidence of chemical substances in e.g. wastewater or the working environment.

If you need to make the assessment more detailed and to find more data, we recommend that you seek out experts within the area.

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