Environmental Project, 907 – LCA and the working environment – Appendix 1

Development of the EDIP method for assessment of the working environment was part of the Environmental Design of Industrial Product programme (the EDIP-programme). The programme was sponsored by the Danish EPA and the participants were five major Danish industrial companies as well as institutes at the Technical University of Denmark.

5.1.1 Purpose

5.1.2 The overall content of the methodology

The purpose of the EDIP project was, as mentioned, to perform an environmental assessment of products. For this purpose a quantitative process assessment method for LCA was developed within the project. The assessment parameters used within the EDIP method are shown in Table 5.1. According to the table the method operates with three groups of assessment parameters: environmental effects, resource consumption, and working environmental effects.

Most of the effect potentials are relatively straightforward to handle in the quantitative assessment method. However, the quantitative assessment of the effect potentials "ecotoxicity" and "human toxicity" demands much more work. To avoid too much unnecessary work, screening methods have been developed. These screening methods can help in the decision of identifying the potential contributes to human toxicity or ecotoxicity (Wenzel, 1996).

5.1.3 The general principles of the methodology

These steps follow the principles outlined in the ISO 14040-series and are generally accepted as a sound methodology in LCA.

The aggregated impacts are subsequently normalized by relating them to the average annual impacts caused by one person in a relevant geographical area (the World/Denmark). In doing so, the contribution to an impact category is related to the potential impact from the society's activities as a whole.

Finally, the impacts are weighted using international or Danish political stated reduction targets for different impacts or specific compounds. Hereby it is assessed which of the potential impacts from a product system are most important.

These steps of the EDIP methodology differ slightly from the ISO 14040 standard, where only a weighting step is recommended. There is, however, little doubt that the normalisation step used in the EDIP methodology adds significant information, provided that the mechanism and principles are scientifically based and understood by the decision-makers.

EDIP operates with three different methods for assessing the working environment, a screening method, a process assessment method and a sector assessment method.

The screening method is a chemical screening method and thereby only covers the chemical working environment of an LCA. The chemical screening method can be used early in the product development or together with the process assessment method. In the last-mentioned case the chemical screening will be a preliminary step for the quantitative assessment with the purpose of deciding which processes to include in the process assessment.

The process assessment method can be used in the assessment of the manufacturing process in the company and possibly for those subcontractors who are able and willing to supply the information needed.

The sector assessment method can be used together with the process method, in processes where specific working environmental data are not available. (Hauschild, 1996, Broberg & Rasmussen, 1996).

5.1.4 Combined environmental and working environmental assessment

The assessment parameters used in the EDIP method are shown in Table 5.1. The method operates with three groups of assessment parameters (environmental effects, resource consumption, and working environmental effects), which all play an equal role in the methodology.

All three groups of assessment parameters are related to the same functional unit and measured by the same environmental unit - the person equivalent. Because the same basic assessment method is used, it is possible to aggregate over several steps in the life cycle and to compare the results from assessment of the working environment with other impact categories.

The data describing the working environment are collected from different sources depending on the assessment method used. For use of the chemical screening method, information about the chemicals used in the specific processes is needed. The screening scores the processes by relating them to European and national lists of dangerous substances and lists of substances with special effects.

The process assessment method requires more specific data from the company. Examples are information concerning impacts due to accidents, chemicals, noise, and monotonous repetitive work. Furthermore, it should be stated how much of the company's production time is used to manufacture the examined product in each of the processes.

When using the sector assessment method similar data should be collected. However, it should be noted that the data in this case represents the average working environmental impacts from the entire sector instead of the specific company and thereby - everything being equal - will lead to higher uncertainty.

5.2 Working environmental assessment methodology

5.2.1 Purpose and goal

The purpose of the sector assessment method is to assess the working environment in processes not directly connected to the primary production process, where EDIP's process assessment is used. In other words, the sector assessment method is used for the processes where it is not possible to achieve very process specific information. In these cases the sector assessment method can give an overview of the number of work-related injuries and accidents for the individual stages of a products life cycle (Broberg & Rasmussen, 1996). The sector assessment method can thus be seen as a supplement to the process assessment method.

5.2.2 Scope of the methodology

Like all other parts of the EDIP methodology the sector assessment methodology can be applied to all processes in the life cycle. As pointed out above, the sector methodology, in contrast to the process assessment method, is best suited for the processes that are not directly connected to the company commissioning the LCA, simply because it is less data intensive and requires less collaboration from external suppliers.

The only formal limitation is that the processes assessed in the sector assessment method must be the processes in which a professional work situation is taking place. As described in an example, transportation is not included as no usable working environmental data could be found (Broberg & Rasmussen, 1996).

The sector assessment method differs to some extent from the assessment method for the external environment by always being performed on a general level. The sector assessment method is based on working environmental data from the examined sector, and does therefore represent the average working environmental impacts within that sector for a certain period of time. Basically, the sector assessment methodology can be compared to the inventories published by e.g. APME on plastic materials. In the assessment steps, the sector assessment method operates with the same kind of normalisation and weighting as for the assessment of the external environment.

The work-related injuries and accidents evaluated within the sector assessment method, are allocated to the product by using the number of working hours needed for the production - the production time. As the information is very general, one cannot be certain whether the data apply to the specific production process or the specific product.

The impact categories included in EDIP's sector assessment method are shown in Table 5.2. The impact categories included are, in principle, the seven ones listed in Table 5.1. The impact categories listed in Table 5.2 are, however, impact categories that can be assumed to come under the larger categories listed in Table 5.1.

Table 5.2. Overview of working environmental impact categories included in EDIP's sector assessment method.

The impact categories are limited to the working environmental assessment parameters chosen for the EDIP methodology (see Table 5.1): Cancer, reproduction damages, allergy, damages to the nervous system, muscle-skeletal damages, hearing damages, and body damages (due to accidents).

The seven impact categories are chosen because they include the work-related injuries that most often are reported. This information is gathered from a working environmental survey of the Danish sectors ("portraits of the Danish sectors") carried out by the Danish Labour Inspectorate (Arbejdstilsynet, 1995).

Impact categories not included in the assessment are injuries such as circulatory diseases, psycho-social diseases, airway and skin diseases not causing allergy, and some other diseases not coming under the above categories. These diseases are relatively seldom reported within the Danish sectors, and therefore they are not included in the assessment (Broberg & Rasmussen, 1996).

By using only the reported work-related injuries, the impact categories are hereby also limited to the types of effects normally reported as work-related injuries (e.g. it is not a tradition that psycho-social injuries are reported as work-related injuries).

The system boundaries sets the limits for which raw materials and other materials should be included in the assessment. For processes included the needed data on working environment can be found in statistical sources describing the work-related injuries within the specific sectors. Some process descriptive data on sector level are also necessary, e.g. production time and production volume. These data can, however, also be found in statistical sources. No interviews or measurements of any kind are necessary, if the sector statistical data exist in literature.

The data should be as recent as possible, preferably given as an average over several years. It should, however, be ensured that no changes in the production method, which could influence the working environment, have taken place within the period the data relates to.

It can be a problem to derive the exact number of working hours used for the production of the specific item. The reason is, that it is often not clear if the number of employees covers full-time employment or part-time work, if the employees have been employed all year, and if the average working hours per employee includes vacation and absence because of illness. The production time will therefore always be somewhat uncertain (Broberg & Rasmussen, 1996).

The parameters used in the inventory, for each phase of the life cycle, are listed in Table 5.3 below.

Number of work-related injuries per year within the sector (for the work-related injuries listed in Table 5.2)
Yield (total production) per year within the sector
Number of persons employed within the sector (both employers and employees who participates in the production (part time/full time))
Total number of working hours per year used for the production (as either working hours per year or per week with a deduction of illness and vacation of the period)

The work-related injuries are listed as an average per year, which makes it possible to compare this information with the annual production size. This will give the number of work-related injuries per ton raw material or per ton product (or per functional unit), which can be added together for each step of the life cycle (Broberg & Rasmussen, 1996). Therefore the necessary data is only the number of work-related injuries and the yearly production. The number of persons employed in the sector is merely used to calculate the number of working hours used to produce the investigated product (the functional unit). The production time per product / functional unit can be used to estimate where the highest or lowest working environmental loads are (Hauschild, 1996).

The working environmental data and the data for the external environment are collected separately. The working environmental data is collected from the Danish Labour Inspectorate, whereas the data for the external environment is collected from other sources.

The number of working hours used to manufacture the specific item can possibly be found at the same source or perhaps from other statistical sources. The total workload for the data collection is therefore not necessarily very high. The data exist for the Danish branches, and can easily be obtained. The major problem is the age of the data, and the uncertainty of calculating the total number of working hours used for the manufacture of the specific item.

EDIP's sector assessment method is not in accordance with the four steps of the impact assessment (category definition, classification, characterisation and weighting) in the ISO 14042 standard. The four steps are not followed individually, but are combined to fewer steps. When the categories are defined the characterisation is at the same time carried out, because it is discussed which working environmental burdens that will give which effects. When the data is classified to the impact categories, the normalisation and weighting are also carried out, because the inventory data is at a form corresponding to the normalised and weighted data used in the process assessment method.

The impact categories used within the sector assessment method are listed Table 5.3. These impact categories are, as mentioned, found by selecting the most frequent reported work-related injuries from the total list of reported work-related injuries (Arbejdstilsynet, 1995).

The categories are defined in accordance with the data source, which means that the number of injuries automatically is classified under the matching impact category. For example all cancer incidents are classified under the impact category "cancer" and all hearing damages are classified under the impact category "noise". The characterisation is also automatically performed because only one kind of impact belongs to the impact category. E.g. the impact category "allergy" is described wide enough to automatically include all kinds of allergies.

The impact categories are defined as having the number of injuries as the category endpoint, which, when divided with the production yield per year, automatically gives the weighted working environmental burdens - the reported work-related injuries per product.

The reported work-related injuries per product is the unit used when comparing alternatives. It may, however, be useful to illustrate the production time used at each process. If the production time is high this might be an indication of a high working environmental burden also. Whereas the production time (cycle time) is the basis of the process assessment method, the production time is not used as an indicator of the working environmental burden in the sector assessment method. A backwards calculation is performed by the use of the normalisation and weighting factors from the process assessment method, just to have a data foundation comparable to the one of the process assessment method. The backwards calculation gives the man hours per product where a working environmentally impact exists, which is the measured or estimated inventory data of the process assessment method (Hauschild, 1996).

A software tool has been developed for the EDIP methodology. There is, however, only very little information on the working environment included in the beta-version of the programme and it must be concluded that assessment of the working environment has not been made operational at this level.

5.3 Cases

One detailed example of how to use the sector assessment method is described. The example is production of electricity in Denmark (Broberg & Rasmussen, 1996). The result of this example is an integrated part of the five examples that are used to illustrate the use of the EDIP method for assessment of the working environment.

5.3.1 Production of electricity

In this example, the total working environmental load for the production of one million kWh is found. The extraction of coal, oil, and gas, as well as the production of the electricity are included in the study. Transportation is not included as no usable working environmental data could be found. The working environmental impact categories listed Table 5.3 are used.

The working environmental data are found in literature from statistical sources, from the International Labour Organisation etc., and by contacting sector associations.

In this case where coal used for producing electricity in Denmark is extracted in several countries, the greatest problem is the uniformity of the data. An example is that England only has data for larger accidents (smaller accidents are not reported or listed), whereas Columbia only lists the accidents that involve lost production time. Another problem is that data for the former USSR does not exist. Alternatively, data from Ukraine has been used. Even when it comes to the Danish statistics on work-related injuries for the production of electricity, lack of data is a problem. Many injury categories are listed but explanations are missing for about 4% of the reported injuries.

Lack of information about the number of working hours per year has also been a problem. Here educated guesses are used to estimate the working time per year with vacation and illness excluded.

The case also shows that it can be a problem to find data from the same period of time for all productions in the examined countries. The lack of data is another source of uncertainty. The substitute data used is however comparable to the data needed.

Because of the lack of data, educated guesses have been necessary in some cases. Besides this problem, the data processing is very straightforward because relatively simple calculations have to be performed.

In this case the work-related injuries are found per one million kWh for the production of electricity in Denmark, and per ton oil, coal, and natural gas for the production of these raw materials. These figures are then simply added together to give the total work-related injuries for the production of one million kWh. The conversion factor used from tonnes raw material to million kWh is the consumption and composition of oil, coal, and natural gas used to produce one million kWh in 1990.

In the described case it has been possible to evaluate which of the working processes that contributes to the highest number of work-related injuries. The example can also be used to calculate the working environmental improvement when changing from using today's (1990) electricity production to e.g. electricity based solely on natural gas.

The conclusion of the example is that the method is very suitable for creating an overview of the number of work-related injuries and accidents in the examined phases of a product's life cycle, if the necessary data can be obtained. The method can thus form the basis of further and more in-depth investigations or form the basis for working environmental improvements.

Generally, it can be said, that EDIP's sector assessment method is not able to distinguish between the working environmental loads of different products if all the processes involved in the life cycles takes place in the same sectors. The only difference between the alternatives will in this case be a difference relating to a shorter or longer production time. The production time is, however, also calculated as an average within the sector, and it can therefore be difficult to distinguish between products. The average production time per product is calculated by multiplying the "total work force per year" with the "total working hours per year", and dividing by the "products produced per year".

The differences between the working environmental loads are larger when different sectors are involved, and the method is suitable for distinguishing between different sectors on the average level.

In the sector assessment method it is clearly the production time that is most significant for the total working environmental load, because the production time is distributed to the working environmental impacts. A process with a short production time becomes insignificant compared to the entire life cycle.

5.4 Discussion

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

In this discussion, the strong and weak sides are firstly summarised (Table 5.4), where after 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.

5.4.1 Methodical requirements

EDIP's sector assessment method is supplementary to EDIP's process assessment method. The sector assessment method is used where no process specific information can be found. As a whole (i.e. both the sector and the process assessment methods), the assessment of the working environment in EDIP is closely connected to EDIP's assessment method for the external environment. Both parts of the methodology are related to the same functional unit, and the results are expressed in the same unit, the person equivalent. It is thus possible to compare the impacts for the external environment and the working environment with each other.

In the sector assessment method the production size on sector level is directly connected to the number of reported injuries within the sector. Comparison with the production size makes it possible to aggregate the impacts over the entire life cycle for all the working environmental parameters (if the statistical data exists for all life cycle phases). The sector assessment method therefore gives a basis for comparing and choosing between alternatives.

EDIP's sector assessment method can be used in all phases of the life cycle, provided that the necessary data can be obtained.

As the sector assessment method is simple and quick to use, the method, alternatively, could be used as kind of a "thorough screening" to indicate in which process of the entire life cycle the highest working environmental burdens exist. For these identified processes, with a high working environmental impact, a more thorough assessment can be carried out via the process assessment method.

5.4.2 Working environmental aspects

By using the statistics of work-related injuries a number of working environmental aspects are included in the study. It is positive that not only chemical aspects are included. The assessment also includes accidents, hearing damages and some ergonomic aspects. However, not all working environmental aspects are included in the assessment method. One reason is that it is decided within the EDIP project simply to include the most frequent injuries. Another reason is that sufficient statistics do not exist for all aspects. This is connected with the fact that it is not tradition to report some work-related injuries, e.g. the psychological injuries, simply because the exposure - effect relationship is not well examined.

EDIP's sector assessment method operates with the term impact threshold. Only impacts exceeding the set impact thresholds are assumed to result in an effect. The exposures and effects are therefore not graded other than "no exposure" or "an exposure resulting in an effect".

5.4.3 Practicability

Using the work-related injuries as the endpoint of the category gives a clear output from the inventory. It is easy to relate to the number of injuries that is likely to occur.

One strong point of EDIP's sector assessment method is that it is easy to use. Only a few data is needed to carry out the assessment, and this data can easily be obtained when statistics of the working environment within the sectors exist. When the data exist only simple calculations have to be carried out to perform the working environmental assessment. This means that the inventory can be completed with reasonable efforts.

It is possible for non-experts to use EDIP's sector assessment method . Few statistical data are needed and only simple calculations have to be carried out.

5.4.4 Data issues

The data exists for the Danish sectors. However, the statistical data for some life cycle phases may be more difficult to find compared to others, e.g. the use phase. Data for other countries may be even more difficult to find, especially for the same period of time.

One weak point of the sector assessment method is that the results do not represent the "true" impacts, but the injuries which are likely to happen when working in the examined sector. The method uses statistics of injuries for the working environment within the different sectors. This will normally give a good overview of the injuries likely to happen, if the statistics are up to date. But the problem is that the statistics usually are a couple of years old, and they do therefore not necessarily represent the level of technology that the LCA is trying to evaluate. Another problem is that some effects, e.g. cancer, take a long time to show in the statistics, which means that the statistics for some impact categories actually represents the working conditions of 10 or 20 years ago.

Furthermore, the statistics used are based on only the reported injuries. In reality the work-related injuries are much higher than the reported injuries. This means that the results of the LCA will underestimate the real impacts of the working environment.

The result of the LCA will not be entirely correct as the assessment method is based on average impact data. The impact data does not represent the actually examined processes within the LCA but an average of the working conditions in all the processes included in the specific sector. The uncertainty of the results will be high if the sector is very heterogeneous with respect to the working environment.

The uncertainty of the results is also increased because average sector statistics are used to calculate the production time. It is difficult to calculate the precise number of working hours used to produce the specific product, when the data consists of the total number of people employed within the sector and the total number of products produced. The production time can only be a very rough estimate.

Because the average impacts of the sector are used, it is automatically assumed that the workers are exposed to the same working environmental burden no matter where or how the products are manufactured. The working environmental impacts are therefore not based on the actual exposure of the workers.

It is difficult to obtain the necessary data from work place assessment because it is the average sector data, which is used for the assessment. However, if all companies use their work place assessment to report working environmental data to the statistical offices, the resulting data material will be more reliable and more correct compared to the data material that exists today. This is, however, not likely to happen in the near future.

5.4.5 Summary of the assessment

In Table 5.5 the above discussion is summarised. The table illustrates how we evaluate EDIP's sector assessment method. The exact meaning of the topics in the first column is described in section 1.10.

5.4.6 Suggestions for improvements

It is difficult to point to specific areas where the sector assessment method can be improved. The developers recognise and describe the inherent weaknesses of the method and the user of the methodology is therefore able to take these into consideration.

The sector assessment method can be seen as an easy and suitable way to establish a crude overview of the potential impacts in the working environment of different sectors. An example of the impacts in electricity production demonstrates that it is possible to use the methodology with a relatively high level of detail.

The calculated cycle time is an important element in the methodology, and by providing this information the method can be used to pinpoint the processes where a more detailed assessment with the process methodology will provide the most interesting information.

5.5 References

Arbejdstilsynet (1995). Sectorbilleder 95 - en samlet dokumentation for arbejdsmiljøet i 20 sectorer. English title:Portraits of sectors 95 - a total documentation of the working environment in 20 sectors. Arbejdstilsynet, Copenhagen.

Broberg O., Rasmussen E (1996). Forskningsrapport Arbejdsmiljø fra vugge til grav. English title: Working environment from cradle to grave. Arbejdsmiljøfondet, Copenhagen.

Wenzel H, Hauschild M, Rasmussen E (1996). Miljøvurdering af produkter, EDIP. English title: Development of environmental friendly industrial products - Environmental assessment of products. IPU/DTU, Miljø- og Energiministeriet - Miljøstyrelsen, Dansk Industri.

Hauschild M (ed) 1996. Baggrund for miljøvurdering af produkter. IPU - DTU, Miljø- og Energiministeriet - Miljøstyrelsen, Dansk Inudstri. English version: Environmental Assessment of Products. Volume 2: Scientific background. Chapman & Hall, 1997.

ISO (1998). ISO 14042 Environmental management - Life cycle assessment - Life cycle Impact assessment. Committee draft (ISO/CD 14042.22), 28.1.1998.

5 EDIP's sector assessment

5.1 The general methodology