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LCA and the Working Environment

2 MUP chemical screening method

2.1 The general methodology

The chemical screening method described in this review was the result of the frame programme "Integrated environmental and occupational assessment of new materials", which was part of the Danish Materials Technology Programme (MUP). The screening method was developed because - within MUP - it was compulsory to assess the impact on the environment and the working environment.

Before the development of this method, another chemical screening method for integrated environmental and working environmental assessments was developed. The method described in this review has been developed in an iterative process, and the complete method has never been used. The method does not strictly follow the general LCA methodology and is therefore difficult to fit into the framework that is made for review of the LCA methods.

2.1.1 Purpose

The purpose of the above-mentioned frame programme was:

• To improve the earlier developed screening method and to ensure that the method was able to identify critical situations in the life cycle of a material or a product
• To use the method on the activities in the Material Technology Centres that participated in MUP
• To develop a flexible method that was usable outside MUP
• To assess the effects of selected materials and activities under MUP and to compare alternative materials.

In addition to this, it was important to ensure that the screening was useful for developers of materials or products.

The leading principles of MUP were therefore to develop a method that - in a relatively quick and inexpensive way - would make it possible to identify the potentially critical situations in a product life cycle. Furthermore the method should be rooted in the international terms and concepts which form the basis of the international standardised methodology.

2.1.2 The overall contents of the methodology

The MUP method was developed for chemical screening of the environmental and working environmental impact of a material or a product.

The product or material life cycle is divided into four phases:

• Production of raw materials
• Production of final products
• Use
• Disposal

To assess the impact from a new material or product seven parameters are included in the method:

1. Consumption of raw materials
2. Consumption of energy and related emissions
3. Waste and recycling
4. Screening for potential health effects
5. Screening for potential environmental impacts
6. Accidents
7. Life time of the materials

The screening of the specific material or product is documented in an environmental file consisting of:

• A short description of the material and the phases of the material life cycle
• An assessment of each of the above-mentioned six parameters (the seventh parameter "Life time" is included in the other parameters) in the four phases of the life cycle. In this part of the environmental file the impacts and potential effects as well as possibilities of improvements are described.
• A summary where the results for the entire life cycle are collected and the critical situations are pointed out.

2.1.3 The general principles of the methodology

MUP's chemical screening method was developed to identify and assess the impact from new materials and products on a very limited data basis. Due to the lack of data and the desire that the method should be quick and inexpensive the method is semi-quantitative.

The chemical screening will often be part of the material development process. An industrial production has seldom been started and there will be no experiences from production, use or disposal of the product. The screening is therefore a snapshot of the environmental and working environmental impact from the material life cycle.

The screening can provide a dialogue between the product develo.per and the environmental expert as well as it can initiate substitutions of materials and processes or be the basis for a more complete life cycle assessment.

MUP's chemical screening method does not strictly follow the terminology and principles outlined in the ISO 14040-series.

The first step is goal and scope definition. The method does not operate with a functional unit. In the "environmental file" mentioned in section 2.1.2, the use of the material or product and its life cycle is described and the components and materials related to the product or material are listed. Materials that are not listed will not be included in the screening.

The next step is the inventory analysis and classification where the impacts are outlined in the environmental file. As mentioned, the parameter "Life time of the materials" is included in the other parameters so the description is performed with only six parameters. For each of the six parameters the impacts are described for all four phases of the life cycle. The impact and potential effects are listed and possibilities of minimising the impact are discussed. Finally the most critical situations are outlined for each of the four life cycle phases.

In the summary the most critical situations are identified in a matrix with the four life cycle phases and the six parameters. Possibilities of improvements are listed. If possible (e.g. for the consumption of energy) the potential global and regional effects are quantified for the four life cycle phases.

2.1.3.1 Working environment in MUP

In MUP's chemical screening method the working environment is included in the parameter "Screening for potential health effects". The screening is not just a working environmental screening as it includes the potential health effects when the chemicals are exposed to the local environment, regionally and globally.

In this review only the part including exposure to the working environment will be described.

MUP's chemical screening method includes an "Analysis of accidents", where the impacts and potential effects (on environment, health and material) from fire, explosion and leaks of toxic substances (by air and fluid) are assessed. The method includes acute effects (death, illness) and chronic effect (irreversible eye damages, respiratory damages and cancer). The analysis of accidents is not further discussed in this review, as the risk of accidents is not a pronounced working environmental parameter.

2.1.4 Combined environment and work environment assessment

The "Screening for potential health effects" covers exposures to the working environment as well as local, regional and global exposures. Therefore some of the exposures are evaluated with the same methods and limits that are used in the "Screening for potential environmental impact". An example of this is bio-accumulation and bio-degradation.

2.1.5 Software tool

A paradigm for the environmental files is available on a computer disc.

2.2 Working environmental assessment methodology

2.2.1 Purpose and goal

The purpose of the parameter "screening for potential health effects" was to develop a method that, primarily from literature references, can quickly perform a screening of the health effects related to a new product or material.

The purpose of this parameter is not a detailed toxicity and health assessment but a screening to identify potential hazardous situations that should lead to substitutions, or undergo a further investigation.

2.2.2 Scope of the methodology

2.2.2.1 System boundaries

The material life cycle is covered by the four phases - production of raw materials, production of final products, use, and disposal. There are no major differences between the assessment method for the different impacts and the method does not set any criteria for exclusion of impacts as all impacts may be relevant at this stage of development.

In the "screening for potential health effects" there are no procedures for allocation.

2.2.2.2 Impact categories

In the "screening for potential health effects" only potential effects related to exposure of chemicals are included. Therefore the working environmental method operates only with one impact category, "Chemical Impacts". The effects covered by the method are shown in Table 2.1

Table 2.1. Effects included in the "screening for potential health effects" in MUP.

According to internationally accepted criteria for labelling and classification the potential health effects of the chemical are divided into three categories and the chemical is assigned an effect-score. Guidelines for how the effects should be categorised and scored are outlined in the method description.

As mentioned in the beginning another method was developed before the development of the method described in this review. In the earlier method, physical working environment and ergonomics were included, but it was omitted in the final method.

2.2.2.3 Data requirements

The "screening for potential health effects" includes an exposure screening and a screening for potential health effects. Both are described in more detail in the following sections. The information needed for the "screening for potential health effects" is collected by an environmental specialist and the product developers.

If possible the exposures of the chemicals are measured, but because the screening is part of the product or material development process, it is often necessary to estimate the exposure from process parameters. This means that the assessment will often be theoretical and not based on observations from the working place.

2.2.2.4 Inventory parameters

The data needed for the exposure screening are:

• a list with names (and CAS No.) of the substances and materials that will be used or processed in the product or material life cycle
• working hygienic measurements of the exposures or
• qualitative and quantitative process parameters

When it is possible to measure the level of exposure it will be assigned a score on the basis of threshold limit values (TLV) in the working environment:

Substances detected => Low exposure (score 1)

Generally <10% of TLV => Medium exposure (score 2)

Frequently >10% of TLV => High exposure (score 3)

It is often not possible to measure the exposure. In this case the following process parameters are used:

• consumption of materials (kg per day)
• open/closed process
• volatility
• dust/aerosol formation
• skin contact

The process parameters are divided into three categories and the process is assigned an exposure-score. Guidelines for how the exposures should be categorised and scored are outlined in the method description.

2.2.2.5 Impact assessment – screening of potential effects

The chemical screening method is not in accordance with the ISO 14042 standard. The method does not operate with the five steps - category definition, classification, normalisation (optional) and weighting (optional). Instead the method operates with an effect screening and a scoring system for the potential effects.

The eight potential effects included in the method are shown in Table 2.1. For each substance the potential effect is assigned a score:

Low effect => score 1

Medium effect => score 2

High effect => score 4

The score depends - amongst other things - on the number of potential effects and seriousness of the effects. The characterisation is based on threshold limit values, labelling criteria, classification rules etc. for the potential effects. The method description includes a detailed guideline on how to assign the effect score.

2.2.2.6 Combining the screening of exposure and effects

The exposure screening and the effect screening are combined in a matrix (Table 2.2).

Table 2.2. Matrix for identifying potentially critical situations.

The method recommends that for all the situations with the score "8" or "16" a more detailed examination should be carried out, the process should be changed, or the chemical/substance should be substituted.

The method does not include any aggregation of working environmental effects in the life cycle and there is no normalisation or weighting of the effects.

2.3 Cases

MUP's chemical screening method was developed in co-operation with the Materials Technology Centres in Denmark. The five Centres have tested the method in 16 cases divided into five groups:

• Composites based on plastics
• Dry covering processes
• Advanced technique for galvanisation
• Advanced technical ceramics
• Powder metallurgy

For each of the 16 cases an environmental file has been completed. None of the evaluated materials or products have been tested in a life cycle assessment before.

The cases showed that it was difficult to obtain data from the processes outside the Centres, e.g. the production of raw material or disposal. This lack of data will most likely be typical when assessing products or materials under development where a production has not been started.

In the cases where the data were available, the screening was able to identify the critical situations in the product or material life cycle.

The screening method was tested, evaluated, and further developed in an iterative process. This means that the final method has never been used but consists of sub-elements that all have been tested individually.

2.4 Discussion

In this section we discuss the strong and weak sides of MUP's method. The text therefore reflects the opinion of the project group. The purpose of the discussion is partly to evaluate the method and partly to learn form the strong and weak sides of the method, and thereby be able to set guidelines for the "perfect" working environmental LCA.

In the discussion, the strong and weak sides of the method are firstly summarised (Table 2.3), after which the points are elaborated. Secondly, an overview of our evaluation of the working environmental LCA is given. Finally, suggestions for improving the method are discussed.

Table 2.3. Strong and weak sides of MUP's chemical screening method.

2.4.1 Methodical requirements

2.4.1.1 Interaction with other parameters in the method

The "screening for potential health effects" interacts well with the other parameters in the screening method, primarily the "screening for potential environmental impacts" and the "accident analysis". The data requirements and the level of assessment are essentially the same for the three parameters.

In the environmental file the six parameters are handled equally and described with the same framework.

2.4.1.2 Interaction with other LCA methods

The method does not relate to other LCA methods and it will be difficult to compare results with other methods.

The "screening for potential health effects" can be used as a tool of its own or can complement results from a quantitative LCA, where the working environmental aspects are not included.

2.4.1.3 Accordance between purpose, data requirements and results

The purpose of the "screening for potential health effects" was to develop a method that - primarily from literature references - could quickly perform a screening of the health effects related to the life cycle of new products or materials. As the data requirements are limited, the screening can be based on literature without working hygienic measurements and the method can identify the critical situations in the material or product life cycle. There is accordance between the purpose, data requirements, and results of the method.

2.4.1.4 Availability of impact assessment criteria

The method description includes a detailed guideline (based on threshold limit values, labelling criteria etc.) for assessment and characterisation of the potential effects. These threshold limit values and labelling criteria will already be available for many of the substances.

2.4.1.5 Dialogue between product developer and environmental expert

As the method assesses the materials or products at a very early stage in the development process, the developer will be very involved in the screening. Furthermore a dialogue between the developer and the environmental expert will be necessary for listing possible improvements of the product or material in the environmental files.

2.4.1.6 Other methodological issues

The method focuses on substances rather than products. The screening does not operate with a functional unit and there are no allocation procedures. Therefore it can be difficult to relate the results of the working environmental screening to the material or product.

The method is semi-quantitative but when possible - e.g. for energy consumption - the impact is quantified.

In the "screening for potential health effects" the exposures and effects are graded in three groups (low, medium or high exposure or effect). The scoring system is easy to use but some of the transparency and information get lost. This can make it difficult to compare the result with results from other LCA methods.

With the scoring system it is not possible to make aggregations of the life cycle phases. In the environmental file all phases (production of raw materials, production of final products, use, and disposal) are described in separate sections. The final result of the chemical screening is a matrix with the four phases and the seven impact categories.

2.4.2 Working environmental aspects

The method includes only the chemical working environment and thereby only a limited number of impacts. No other impacts are covered by the assessment. This leads to the risk of preclusion of very significant working environmental impacts such as noise, vibrations, dust, and monotonous repetitive work.

The method can be used in all life cycle phases as long as chemical information and measurements of exposures or process parameters are available.

Both the exposures and the effects are assigned a score and thereby graduated in three levels. When the effect-score and the exposure-score are combined in a matrix it is easy to assess for which situations a more detailed examination should be carried out or the process or chemical should be changed or substituted.

2.4.3 Practicability

2.4.3.1 Scoring system

The scoring system operates with simple guidelines showing how to assign a score (low, medium or high) to the exposures and effects. The scoring system and the matrixes are simple to use and give a quick and clear overview of the potential critical situations where a substance should be substituted, a process changed or a more detailed examination should be carried out. Another advantage of the scoring system and the matrixes is that they make it fairly easy to compare alternative products or materials that have been assessed with the screening method.

2.4.3.2 Required expertise

To use the method extensive knowledge of chemical substances and processes is required. This demands some involvement of a person with chemical knowledge and experience with working hygienic measurements or assessment of processes.

2.4.3.3 No database

The method does not include a database, which would be a valuable help when assessing the effects of the chemicals.

2.4.4 Data issues

As the "screening for potential health effects" solely covers exposure of chemicals it only requires a limited number of data. If possible the exposure should be measured but more often the exposure will be estimated from process parameters. This means that the critical situations can be identified without a large number of measurements and on the basis of literature references.

As the method to a large extent is based on literature information most of the data will be relatively easy to obtain and only a few measurements will be necessary.

2.4.5 Summary of the assessment

In Table 2.4 the above discussion is summarised. This table illustrates how the project group evaluates the MUP method. The exact meaning of the topics in the first column is described in section 1.10.

Table 2.4. Fulfilment of the MUP method.

Topic	Evaluation of the MUP method
Methodical requirements
Integration with LCA for external environment
Applicability in LC-phases
Aggregation possible
Working environmental aspects
Coverage of WE'al issues
Graduation of exposures and effects
Practicability
Practical in use
Software tool
Transparency
Data issues
Data reliability
Amount of data in existing database
Data accessibility
Data can be obtained by WPA

= missing, = poor, = acceptable, = good, = excellent

2.5 References

Broberg O., Rasmussen E., 1996. Arbejdsmiljøfondet, Forskningsrapport "Arbejdsmiljø fra vugge til grav". English title: "Working environment form cradle to grave".

ISO, 1997. ISO 14040: Environmental management - Life cycle assessment - Principles and framework. First edition, 15.06.1997

ISO (1999). ISO/FDIS 14042:(E). Environmental management – Life cycle assessment – Life cycle impact assessment.

MUP, 1994a. Schmidt A et al. "Livscyklusmodel til vurdering af nye materialer, Metoder, vurderingsgrundlag og fremgangsmåde", English title: "Life Cycle Model for assessment of new materials: Methods, basis for assessment and procedures".

MUP, 1994b. Schmidt a et al. "Livscyklusmodel til vurdering af nye materialer, Baggrund, principper og anvendelse", English title: "Life Cycle Model for assessment of new materials: Background, principles and use".

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Version 1.0 April 2004, © Danish Environmental Protection Agency