Handbook on environmental assessment of products
3. Carry out an initial environmental assessment
For the initial environmental assessment, you will be working with a MECO chart.
The MECO chart will help you collect your data in a systematic and easily accessible way. It helps create an overview of the environmental impact of your product.
You must prepare a MECO chart for each product included in your environmental assessment. In what follows, we will describe how to work with the chart for a single product.
The principles of the MECO model place the main emphasis on the materials, ancillary materials, and energy consumed throughout the product life-cycle. It is difficult to accurately calculate the emissions to air and water and waste generated during a product's life-cycle. Such flows can be included, but only to a limited degree.
In the following, we explain how the data you have already collected will be processed. This will be followed by instructions on how the processed data can be interpreted. Finally, we will look at whether you should proceed with your work and how.
3.1 Preparing a MECO chart
When preparing a MECO chart, your work will be based on the functional unit (part B, chapter 1) and the life-cycle you have outlined (part B, chapter 2).
When filling in the MECO chart, you need the product description outlined in chapter 2, a calculator, and Appendix B at the back of this book.
The MECO chart is shown in figure 3.1. You use it by filling in one row at a time. First, you fill in the row describing the materials used in all phases of the product life-cycle; then you move on to energy, and so on.
In the MECO chart, materials consumption is indicated in quantities measured in kg (or another suitable unit of measurement), and converted into resource consumption. Energy consumption is calculated in terms of primary energy and the resources spent on generating this energy. The rows detailing "Chemicals" and "Other" involve only one method of calculation each.
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Raw materials phase |
Production phase |
Use phase |
Disposal phase |
Transport phase |
Raw materials |
Quantity |
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Resources |
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Energy |
Primary |
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Resources |
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Chemicals |
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Other |
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Figure 3.1
MECO chart
Sections 3.1.1 to 3.1.4 include instructions and examples to help you complete the MECO chart. Sections 3.1.1 and 3.1.2 include a number of formulae. These are marked with numbers, e.g. (1), and are collected in an overview in appendix A.
3.1.1 Materials
Materials are calculated as the materials used to manufacture the product as well as the materials consumed in connection with use or maintenance of the product. The last step, disposal, may include reuse or reprocessing, e.g. of plastic or paper.
Begin by identifying the total material consumption for each phase, calculated by type of material. You already have the basic information necessary to do this from your data collection efforts, as illustrated in table 2.3 in chapter 2. Enter this information on the top line under the heading "materials".
Example B3.1: Material consumption for a coffee maker From chapter 2, table 2.3, we have the following information for the raw materials phase: Plastic, impact-resistant polystyrene (PS):
From chapter 2, table 2.3, we have the following information for the production phase:
From chapter 2, table 2.4, we have the following information for the use phase:
From chapter 2, table 2.5, we have the following information for the disposal phase:
Other materials are all sent for incineration. Transport phase: no materials consumption. The above figures are shown inserted in the MECO chart in example B3.7 |
You now need to identify the resources/raw materials used for each material.
For some materials, you probably already know which raw materials are being used. For others, table B.1 in Appendix B may be helpful.
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Resource consumption is measured in milli-Person Reserves, abbreviated as mPR. With
this conversion, account is taken of the fact that some materials are in plentiful supply,
while others are scarce. Scarce resources are accorded greater weight than the plentiful
ones, as it is more harmful to the environment to use 1 kg of a material which is in short
supply than 1 kg of a material where there is plenty to go around.
For this conversion of materials consumption into resource consumption, use table B.1 in Appendix B. |
Identify the quantity of your material(s) in kg and calculate the mPR value for each
material. Some of the materials used will involve only a single raw material (e.g.
aluminium), while others involve more (e.g. steel).
Calculate:
(1) no. of kg of material [A] x mPR/kg for [A] = mPR for material [A]
Example B3.3: Conversion into milli-Person Reserves Table B.1, Appendix B, includes the following conversion factors:
When a given material comprises more than one raw material, calculations must be carried out individually for each raw material. The milli-Person Reserves for 2 kg of aluminium and steel are calculated as follows:
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Table 1 in Appendix B includes comments for some materials. These comments concern
significant emissions or other important issues in connection with production of the
materials. Transfer these comments to the MECO chart. If the comments concern waste, list
them in the "Materials" row. If they are about emissions, list them in the
"Chemicals" row. Other comments, for example about working-environment issues,
should be listed in the "Other" section.
If you cannot find information about one or more materials used in your product, simply list the relevant material(s) on the MECO chart and then decide whether you want to do more about it later. |
Example B3.4: |
Resource consumption for the raw materials phase,converted into mPR |
Polystyrene |
1.12 kg x [0.02 mPR/kg crude oil + 0.02 mPR/kg natural gas] = 0.022 mPR natural gas |
PVC |
0.02 kg x [0.01 mPR/kg crude oil + 0.01 mPR/kg natural gas] = 0.0002 mPR crude oil + 0.0002 mPR natural gas |
Glass |
0.34 kg x 0 mPR/kg = 0 mPR |
Aluminium |
0.11 kg x 1.5 mPR/kg = 0.165 mPR Al |
Copper |
0.02 kg x 16.5 mPR/kg = 0.33 mPR Cu |
Steel, machine steel |
0.3 kg X [0.08 mPR/kg
Fe + 0.05 mPR/kg Mn] |
Cardboard |
0.39 x 0 mPR/kg = 0 mPR |
If materials are used during the production phase or use phase, calculations must also be
carried out for all the relevant materials consumed there.
During the use phase, a total of 7.3 kg coffee filters and 290 kg coffee are used. These "materials" are made from renewable resources and so need not be included in your calculations of materials. Washing-up liquid and acetic acid is used for cleaning. The washing-up liquid is ignored because of the small quantities used. The acetic acid is assessed in the "Chemicals" section. The use phase involves consumption of a total of 3,690 litres of water. Water is regarded as a renewable resource and is not included here. This means that the use phase features no contributions to your calculations of materials consumption. |
If your product involves reuse or reprocessing of materials during the disposal phase,
your calculations must also take this into account. This is done by carrying out
"compensation" for the recycled materials, measured in mPR. Use the formula
applied during the raw materials phase.
In the "coffee maker" example, it is assumed that 50% of the steel and glass is recycled. This means that compensation will be carried out for the following:
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Enter the result of your calculations in the MECO chart in the row labelled
"Materials". All results should be entered as the sum of each of the resources
addressed.
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Raw materials phase |
Production phase |
Use phase |
Disposal phase |
Transport phase |
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Quantities |
PS: 1.12 kg PVC: 0.02 kg Glass: 0.34 kg Cardboard: 0.39 kg Aluminium: 0.11 kg Copper: 0.02 kg Steel: 0.3 kg |
Release agent Lubricant |
Paper: 7.3 kg Coffee: 290 kg Water: 3,690 kg |
Reprocessing Glass: -0.17 Steel: -0.15 Waste incineration: 299.23 kg |
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Resource consumption |
Crude oil: 0.0222 mPR Natural gas: 0.0222 mPR Al: 0.165 mPR Cu: 0.33 mPR Fe: 0.024 mPR Mn: 0.015 mPR |
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Fe: -0.012 mPR Mn: -0.008 mPR |
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3.1.2 Energy
Energy comprises energy consumption in the form of electricity, steam, heat, and other energy as well as energy for transport. It also includes the energy contained within certain materials. Plastics, for example, contain a lot of energy – they can be burnt to release that energy, which can then be utilised. By contrast, substances such as sand contain no reusable energy.
The process energy used may be electricity or come from oil, gas and petrol. For the sake of simplicity, wind power, water power and nuclear power are not included in our calculations.
You need to identify the energy consumption and the type of energy used for each life-cycle phase of your product. In addition to this, you need to include the energy consumed to manufacture the materials. These figures can be looked up in the appendices.
The energy consumption outlined above is known as "primary energy". This figure needs to be converted into resource consumption. For the purposes of this method, we have chosen to calculate all energy consumption as consumption of crude oil reserves.
3.1.2.1 Energy consumption within the raw materials phase
Table B.2 in Appendix B lists the energy consumption necessary to extract a number of different resources and form them into usable raw materials.
Calculate the energy consumption for the raw materials used in the product. Energy consumption is calculated as primary energy by calculating:
| (2) | Amount of material [kg ] x |
| Primary energy for the material [Mj/kg] = | |
| Primary energy consumption [Mj] |
Remember to include all raw materials – even those based on renewable resources. |
Example B3.8: Primary energy consumption for materials production The list of materials is from example B3.1. The raw materials phase:
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3.1.2.2 The production phase
Calculate the process energy for the production phase by type of energy. Table B.3 in Appendix B may help you identify the energy consumption for the relevant processes. The table lists information on energy consumption for selected processes.
It is not always possible to clearly identify energy consumption for individual processes. Often, the total energy consumption of the entire company will be known, and this figure then needs to be reallocated, i.e. distributed among all the products manufactured. If the company cannot provide appropriate directions for such distribution, you can carry out a weighted distribution based on the number of products sold times sales price or stock turnover.
If no data for the production phase is available, you can set the energy consumption at 30% of the corresponding energy consumption during the raw materials phase. |
For energy-intensive processes, e.g. where large quantities of water are heated or cooled,
the process-energy values may be very high.
When gas or oil is burnt and the resultant heat is utilised, the raw materials used to create this energy are utilised 100%.
Manufacture of electricity, however, entails relatively large losses at the power plant. Only 40% of the energy delivered to the power plant can be utilised as electricity.
If the energy consumption values have been calculated in the form of electricity, you need to convert this energy consumption into primary energy, measured in MJ. Use these formulae:
(3) Electricity consumption [MJ] x 2.5 = primary energy consumption [MJ]
(4) Electricity consumption [kWh] x 9 = primary energy consumption [MJ]
If you have identified energy consumption in the form of energy resources, you need to convert the energy consumption into MJ by using this formula:
| (5) | Energy resource [kg] x calorific value [MJ/kg] = primary energy consumption [MJ] |
You can look up the calorific values of various energy resources in Appendix B, table B.4.
Example B3.9: Energy consumption for production of a coffee maker Chapter 2 includes information on the processes used to manufacture the coffee maker. Table B.4 in Appendix B states that pressure die casting of aluminium involves an energy consumption of 20-50 MJ/kg. No data is available for the other processes. It is estimated that processing of materials accounts for 20 MJ/kg. As a total of 1.91 kg need to be processed for each coffee maker, this equals an energy consumption of 38.2 MJ in the form of electricity. This electricity consumption is converted into primary energy; 38.2 x 2.5 MG = 95.5 MJ. |
3.1.2.3 The use phase
The amounts of energy consumed during use of the product can be insignificant or very great. Energy consumption must be calculated by energy form and be converted into MJ.
Identify the direct energy consumption and consider whether you need to compensate for the energy savings caused by secondary services during the use phase – if there are any secondary services, that is.
Section 3.1.2.2 contains information on converting electricity consumption and energy resources.
Example B3.10: |
Energy consumption during the use phase for the coffee maker |
The coffee maker consumes energy in the form of electricity: 540 kWh. 540 kWh x 9 MJ/kWh = 4,860 MJ primary energy. In chapter 2, we saw that we compensate for the heat generated by the coffee machine in our total considerations. We do this to take energy savings into account. Here, 360 kWh are saved on heating. Homes are usually heated through consumption of oil. 360 kWh x 3.6 MJ/kWh = 1,296 MJ. This is to say that the heat generated by the coffee maker makes for total savings of 1,296 MJ primary energy. As a result, the total primary energy consumption during the use phase is 4,860 MJ – 1,296 MJ = 3,564 MJ. |
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You should also consider whether energy is consumed in connection with
cleaning/maintenance of the product. You will have to make an estimate of such energy
consumption, as the exact figure is rarely known – and it may not be possible to
calculate it accurately at all. Remember to make a note explaining the reasons and
assumptions behind your estimate.
Materials may also be consumed during the use phase – such materials must also be included in your assessment. Calculations are carried out in the same way as for energy consumption for materials during the raw materials phase. See section 3.1.2.1.
Example B3.11: |
Energy consumption for materials during the use phase for the coffee maker |
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3.1.2.4 The disposal phase
Once you know how the product is disposed of, you can calculate energy consumption or energy development.
Plastic, paper, cardboard and other flammable, discarded parts of a product will be disposed of either via recycling or incineration. If such disposal takes the form of incineration, you must compensate for the heat generated in the energy accounts. This preliminary environmental assessment does not take into account heat losses and the like.
Heat generation is calculated by means of the calorific value |
Calculate the energy contents for each material and enter the total heat generated in the
MECO chart. Use the column labelled "calorific value" in table B.2 in Appendix B
and calculate:
(6) Material [kg] x calorific value [MJ/kg] = heat generation [MJ]
Example B3.12: Heat generation upon disposal of the coffee maker |
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Heat generated by incineration in the disposal phase:
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In cases where disposal involves special treatment, you must ensure that the relevant
energy consumption is identified and included in the total calculations. This might, for
example, concern reprocessing of materials.
Table B.3 in Appendix B lists primary energy consumption values for a few, selected reprocessing processes.
If you do not have any information about the energy consumed in connection with reprocessing, you can set the value at 50% of the energy used to make the material from scratch. |
Example B3.13: Energy consumption for reprocessing for the coffee maker |
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In our example with the coffee maker, we see that 50% of the steel and glass used to make the coffee maker is reprocessed. This consumes energy. Table B.3 in Appendix B has information on the energy consumed when reprocessing materials. Primary energy consumption: |
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0.17 kg glass x 7 MJ/kg |
= |
1.2 MJ |
0.15 kg steel x 40 MJ/kg |
= |
6.0 MJ |
Total energy consumption for reprocessing |
= |
7.2 MJ |
3.1.2.5 Transport
The energy consumption for transport is based on calculations of the amount of goods transported throughout the entire product life-cycle and the distances covered. These calculations are described in chapter 2, table 2.6.
The energy consumption per kilometre depends on the form of transport used. Table 3.1 shows the energy consumption associated with three different forms of transport.
Table 3.1
Energy consumption for transport
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Energy consumption |
Train |
0.0008 MJ/(kg x km) |
Ship |
0.001 MJ/(kg x km) |
Truck |
0.005 MJ/(kg x km) |
Take the chart detailing the transported quantities and distances and table 3.2 as your
basis for calculating the total energy consumption for transport. You do this by means of
the following formula:
| (7) | The sum of: (transported material [kg] x distance [km] x energy consumption[MJ/(kg x km)]) = total energy consumption[MJ] |
Example B3.14: Energy consumption for transport for the coffee maker |
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Raw materials, car |
2,000 km x 2.3 kg x 0.005 MJ/(kg x km) |
= |
23.0 MJ |
Coffee, ship |
10,000 km x 290 kg x 0.001 MJ/(kg x km) |
= |
2,900.0 MJ |
Coffee filters, car |
1,000 km x 7.3 kg x 0.005 MJ/(kg x km) |
= |
36.5 MJ |
To end user, car |
100 km x 2.3 kg x 0.005 MJ/(kg x km) |
= |
1.2 MJ |
Disposal, car |
5 km x 299.6 kg x 0.005 MJ/(kg x km) |
= |
7.5 MJ |
Total for transport |
2,968 MJ |
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3.1.2.6 Total statement
You now need to present a total statement, accounting for all the energy consumed for the various processes.
For products where transport is not a significant issue, we recommend that you adapt the MECO chart by removing the "transport" column.
Example B3.15: Primary energy consumption |
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Raw materials phase |
Production phase |
Use phase |
Disposal phase |
Transport |
Primary energy |
154 MJ |
96 MJ |
6,092 MJ |
7 MJ |
2,968 MJ |
Compen- sation |
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-1,296 MJ |
-4,548 MJ |
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Sum |
154 MJ |
96 MJ |
9,656 MJ |
-4,541 MJ |
2,968 MJ |
Net consumption of primary energy: 8,333 MJ |
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You now have to convert the energy consumption values into the equivalent consumption of
oil resources. This is done by means of the following formula:
| (8) | Energy consumption [MJ] / 1,025 [MJ/mPR oil] = consumption of oil resources [mPR] |
Enter the resultant values for energy resources, measured in mPR, in the MECO chart for each life-cycle phase.
Example B3.16: Primary energy consumption, total |
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Raw materials phase |
Production phase |
Use phase |
Disposal phase |
Transport |
Primary energy |
154 MJ |
96 MJ |
10,952 MJ |
7 MJ |
2,968 MJ |
Compen- sation |
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-1,296 MJ |
-4,548 MJ |
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Sum |
154 MJ |
96 MJ |
9,656 MJ |
-4,541 MJ |
2,968 MJ |
mPR oil |
0.15 mPR |
0.09 mPR |
9.42 mPR |
-4.43 mPR |
2.90 mPR |
The net consumption of resources corresponds to 8.68 mPR oil. |
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3.1.3 Chemicals
In this connection, "chemicals" is a wide concept. Chemicals comprise chemical substances used in the product itself as well as all ancillary materials used throughout the product life-cycle. This will mainly concern ancillary materials used to manufacture the product, but ancillary materials used for e.g. maintenance during the use phase should also be included. If you know of any specific chemical substances which are being emitted or discharged into the environment, you should also include them in your assessment.
Take tables 2.3 – 2.5 in chapter 2 as your point of departure and prepare a list of all the ancillary materials and other chemicals used during the product life-cycle. Include information on the quantities used.
3.1.3.1 Information about chemicals
It is usually difficult to get exact information about the chemical substances found in a given product. It is, however, necessary to collect as much information as possible in order to assess the environmental impact.
The most relevant information can be obtained from the suppliers' directions. All manufacturers and importers of hazardous chemicals must prepare such instructions. |
Good supplier directions comprise 16 items, include a PR number (Product Register No.) and
should not be older than two years.
Item 2 of suppliers' directions list the contents of hazardous substances, including information on the approximate quantities and a danger classification.
Appendix B includes an overview of individual danger categories. It also provides explanations of R phrases and S phrases.
If you need to look for more information about a substance, having a CAS number is helpful. CAS is short for Chemical Abstract Service, and each CAS number is unique for the chemical substance in question.
If you have a chemical name – in some cases a commercial name is enough – of the chemical you want more information about, you can often find help on the internet, e.g. at http://chemfinder.camsoft.com/. Here you can find information on substance properties, limit values, and so on. You can also use the handbook entitled Hawley's Condensed Chemical Dictionary to find CAS numbers, explanations of abbreviations, and much more. |
Example B3.17: Ancillary materials |
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Release
agent |
60-100% crude oil distillate, labelled: Xn, R65 |
Lubricant |
60-100% crude oil distillate, labelled: Xn, R65 |
Bleach |
5% hydrogen peroxide, labelled: C, R34 |
Decalcifier |
30% acetic acid, labelled: C, R34 |
Washing-up
liquid |
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3.1.3.2 Assessing chemicals
You should collect the information about all the chemical substances included in the product life-cycle in a chart as illustrated in table 3.2
Table 3.2
Assessment of chemicals
Substance |
Assessment |
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Name |
CAS no. |
Use |
Classification |
The Impact List |
The List of Undesirable substances |
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Fill in the first four columns of the chart with the information you have.
The "Impact List" is a special list prepared by the Danish Environmental Protection Agency. It comprises approximately 1,400 substances which are regarded as particularly problematic due to their environmental and health-related properties.
As at 2000, the "List of Undesirable Substances" numbered approximately 60 substances. The relevant substances have been included on this list because they are widely used and because the Danish Environmental Protection Agency regards them as particularly problematic.
The "List of Dangerous Substances" comprises a very large number of substances which have been assessed by the EU in terms of the danger they represent to the environment and human health. These substances are known as classified substances. The List of Dangerous Substances is essentially a list of examples, but even so it contains many substances which are widely used.
Check whether any of the substances on your chart are included in these lists. If a substance appears in one of the lists, mark this in the table by checking one or both of the columns with the headings "Impact List" and "List of Undesirable Substances". If the substance appears in the List of Dangerous Substances, you should enter the substance classification in the relevant column.
The lists mentioned above do not address chemical substances which degrade the ozone layer, as these substances are already largely banned in Denmark. If, however, you are dealing with products such as cooling systems, fire extinguishers or foam insulation, you need to be aware of whether the substances are ozone-depleting. You can look this op in Appendix B, table B.7.
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Substance |
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Assessment |
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Name |
CAS no. |
Use |
Classification |
The Impact List |
The List of Undesirable Substances |
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Crude oil distillates |
64742-47-8 |
Release agent |
R65 |
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X |
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Crude oil distillates |
64742-47-8 |
Lubricant |
R65 |
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X |
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Hydrogen peroxide |
7722-84-1 |
Bleach |
C, R34 |
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Acetic acid |
64-19-7 |
Decalcifier |
C, R34 |
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Use the column "other" to note down any issues which are significant for the environment and which have not been addressed in connection with your work with raw materials, energy, or chemicals.
Relevant issues might involve working-environment issues or special conditions regarding noise or odours which have not been addressed in any of the other sections.
You should also think about whether you need to look at any other issues in connection with the external environment. For example, this might involve changes to or sequestration of large areas of land in connection with raw materials extraction or landfilling. If the extraction of raw materials involves use of energy from waterpower, it may be relevant to look at the changes made to large areas of land due to damming.
Example B3.19: Other issues (examples) Raw materials: For the coffee maker, it may be relevant to consider working-environment issues in connection with extraction and processing of the metals used. It might also be relevant to take a closer look at how the coffee is produced. Manufacture: The manufacture of the coffee maker involves moulding of polystyrene. This can cause problems in terms of the working environment. Some working processes can cause noise. Use: Acetic acid is used to decalcify the coffee maker. When heated, acetic acid gives off a strong smell. Disposal: Waste sorting often gives rise to working-environment problems. Shredding of products which contain metals causes noise. Transport: It may be relevant to look into special conditions in connection with matters such as transport of dangerous substances. |
3.2 Interpreting the MECO chart
3.2.1 The MECO chart
Start by preparing a full MECO chart with all information as described in the last section if you have not done so already.
If your environmental assessment involves several products, the charts should look as similar as possible. It is important that you save any secondary charts for later, in case you need them for a more in-depth assessment.
It is important that you discuss your results with someone else – and this might well be someone who doesn't work at your company. For example, you might want to talk to someone from a company you work with, a network, a different company within your group, or something similar. The person you discuss matters with must know about the relevant product(s) and have some knowledge of environmental assessments. The objective of this discussion is to ensure that you have included all the significant aspects in your work. |
Example B3.20: MECO chart for the coffee maker Below is a total MECO chart for the coffee maker used in our example: |
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Raw materials phase |
Production phase |
Use phase |
Disposal phase |
Transport phase |
Raw materials Quantities |
PS: 1.12 kg PVC: 0.02 kg Glass: 0.34 kg Cardboard: 0.39 kg Aluminium: 0.11 kg Copper: 0.02 kg Steel: 0.3 kg |
Release agent Lubricant |
Paper: 7.3 kg Coffee: 290 kg Water 3,690 kg |
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Resource consumption |
Crude oil: 0.022 mPR Natural gas: 0.022 mPR Al: 0.17 mPR Cu: 0.33 mPR Fe: 0.0024 mPR Mn: 0.015 mPR |
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Fe: -0.012 mPR Mn: -0.008 mPR |
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Energy Primary |
154 MJ |
96 MJ |
9,656 MJ |
-4,541 MJ |
2,968 MJ |
mPR (crude oil) |
0.15 mPR |
0.09 mPR |
9.42 mPR |
-4.43 mPR |
2.90 mPR |
Chemicals |
Fluorides used when manufacturing aluminium. Heavy metals used when making copper. Vinyl chloride monomers used for making PVC. |
Crude oil distillates (undesirable?) Hydrogen peroxide (C, R34) |
Acetic acid (C, R34) |
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Other |
Extraction of metals, working environment issues |
Die casting of PS, emanations |
Decalcification, odours from acetic acid |
Not known |
No comments |
3.2.2 Interpreting the information on materials
The assessment of resources, measured in mPR, takes into account whether the materials used in the product have been made from scarce or plentiful resources. As a result, the assessment can be used directly for environmental comparisons.
Remember that the assessment includes only non-renewable resources such as metals and plastic. When converting figures into mPR, only known reserves have been taken into account, and so the calculations of mPR are subject to some uncertainties. |
All materials consumption in this initial environmental assessment has been calculated for
new resources. This makes for a conservative assessment if it is possible to use
reprocessed materials in the relevant product. For example, it is important to use new
aluminium if you wish to exploit the conductive properties of this material, whereas it
would be perfectly possible to use reprocessed aluminium for e.g. a coffee maker.
If the MECO chart features waste, you should be aware that various categories of waste cannot be immediately compared.
You can compare impacts measured in mPR between the individual life-cycle phases of a given product. You will also be able to compare impacts measured in mPR for the same life-cycle phase for two or more products. |
When carrying out your comparisons, you should take note of any comments in the
"other" box in connection with materials.
Remember to take into account any lack of data and insecurities. If significant materials which form part of the product are not listed in Appendix B.1, you will have to seek assistance to carry out this calculation. You could, for example, contact one of the knowledge centres working with LCA. |
A given value for resource consumption should be 50% greater than a comparable value before you can conclude that a significant difference exists. |
Example B3.21: Materials consumption for the coffee maker The MECO chart shows that the raw materials phase and the use phase are the most significant phases in this regard. The information on quantities shows that the largest amounts of raw materials are used during the use phase (coffee and water). The weighted inventory shows that the raw materials phase is the most harmful in environmental terms. Consumption of copper and aluminium are the most important elements. |
3.2.3 Interpreting energy figures
The energy consumption has been measured in terms of process energy and the energy contents of the materials used.
You can choose to look at energy consumption measured in MJ, or you can look at the consumption of energy resources measured in mPR. |
For example, you can prepare energy balance sheets measured in MJ for two different
products and compare them.
The calculations on energy resources measured in mPR can be used for comparisons with other resource consumption under "materials".
Remember to take into account lack of data and insecurities. If significant materials or processes which form part of the product life-cycle are not listed in Appendices B.2 – B.5, you will have to seek assistance to carry out this calculation. You could, for example, contact one of the knowledge centres working with LCA. |
A given value for energy consumption should be 50% greater than a comparable value before you can conclude that a significant difference exists. |
Bear in mind that the primary energy consumption has been converted into oil consumption.
This makes for a very conservative assessment. Energy can be generated from other, less
environmentally harmful raw materials.
Even so, energy consumption measured in mPR tells us something about the resource consumption involved, and so these figures can be used to carry out comparisons with the resource consumptions calculated under the heading "materials".
Example B3.22: Energy consumption for the coffee maker The MECO chart for the coffee maker shows that the energy consumption during the production phase is on the same level as consumption during the raw materials phase (154 MJ). The greatest energy consumption takes place during the use phase (9,656 MJ), but significant energy is also released when the coffee maker is finally disposed of by means of incineration (4,541 MJ). The large consumption of energy is mainly the result of the energy used to produce the coffee and the electricity consumed by the coffee maker. The energy consumption for transport (2,968 MJ) is very high seen in relation to the raw materials and production phases. As energy consumption for transport usually involves consumption of oil, resource consumption has not been overestimated in this regard. When comparing the various figures, energy consumption calculated as resources is significantly higher than the resource consumption associated with materials. |
3.2.4 Interpreting chemical figures
To interpret the figures established for chemicals, you should use your additional chart, as illustrated in table 3.2, in addition to the MECO chart.
3.2.4.1 Chemicals lists
If a substance is listed in the List of Undesirable Substances, this is a clear indication that the substance has problematic properties in terms of the environment and/or working environment. It is likely that the substance will be banned or subject to stringent regulation in the short or longer term.
If a substance is listed in the Impact List, this signifies that it has undesirable properties in terms of the environment or working environment. The substance may be subject to regulations in the near future.
The List of Dangerous Substances is a list of examples. It comprises a wide range of substances which have primarily been assessed on the basis of their impact on human health. For some substances, assessment of environmental issues has also been carried out.
If a given substance does not appear in the List of Dangerous Substances, this does not mean that the substance is insignificant. All you can conclude from such an absence is that you know nothing about its properties.
3.2.4.2 An initial sorting
You can use the three lists mentioned above to carry out an initial sorting of the impacts on the environment and working environment associated with the substances found in the life-cycle of your product. In what follows, we describe one possible way to sort substances into one of three categories: type 1, 2 or 3.
| Type 1: | Highly problematic substances Substances included in the List of Undesirable Substances and the Impact List. Ozone-depleting substances, cf. Appendix B, table B.7. |
| Type 2: | Problematic substances Substances included in the List of Dangerous Substances for reasons other than that they are flammable or pose a risk of explosions. Substances about which you have no information. |
| Type 3: | Less problematic substances Substances which are only included in the List of Dangerous Substances because they are flammable or pose a risk of explosions. Substances which have very little harmful impact
on the environment. |
Example B3.23: Initial sorting of chemicals for the coffee maker. |
|
The ancillary materials associated with the coffee maker are listed in B3.17. The initial sorting for these substances reveals these categories: |
|
Acetic acid |
Problematic substance |
Crude oil distillate |
Highly problematic substance |
Hydrogen peroxide |
Problematic substance |
Table 3.3 shows some examples of assessments of chemicals. As it will appear, the
substances cadmium and chromium are designated as highly problematic, as they are toxic
and are listed in both the Impact List and the List of Undesirable Substances. Xylene and
2-propanole are less harmful to the environment than the two metals, as will be apparent
from their classification and type.
Table 3.3
Examples of assessments of chemicals
Name |
Cadmium (e.g. cadmium chloride) |
Chromium(VI) (e.g. chromium trioxide) |
Xylene |
2-propanole |
CAS no. |
10108-64-2 |
1333-82-0 |
106-42-3 |
67-63-0 |
Classification |
T, |
O,T,C,N |
Xn, |
F, |
The Impact List |
X |
X |
|
|
The List of Undesirable Substances |
X |
X |
|
|
Type |
Highly problematic substance |
Highly problematic substance |
Problematic substance |
Less problematic substance |
Exactly how many substances you choose to assess further depends on your overall goal, the
relevant quantities of the individual substances, and the number of substances involved.
Begin by including the most important substances; you can supplement this later if you
wish.
3.2.4.3 Impact on human beings and the environment
As an aid to interpreting the importance of the chemicals, you might want to carry out further assessment of what happens to a given chemical during and after use - what are the possibilities for exposure to the relevant chemical? (Human exposure and/or environmental exposure). Even if you do not calculate the quantities involved, the results may well indicate where the chemicals might be problematical.
If several chemicals or ancillary materials are used during a product's life-cycle, or if large quantities are used, it is important to be clear on how they may affect their surroundings.
During use, some chemicals may give rise to problematic working-environment conditions. In other contexts, the impact on human beings will be minimal.
A number of ancillary materials will follow the product, e.g. paint. Others will be regarded as waste after use, e.g. discarded roller oil, and yet others will be emitted with wastewater from the company, e.g. alkaline degreasing agents.
|
|||
Substance: |
|
||
Does the substance follow the product (yes/no)? |
|
||
Type: |
|
||
Impact on the surroundings |
|||
Working environment |
Air |
Water |
Waste |
Figure 3.2
Chart for assessment of the impact of a given substance
Use a chart like the one illustrated in figure 3.2 for each chemical or ancillary material that you choose to assess in greater detail. State the substance name in the first line of the chart.
You need to assess whether the chemical follows the product during its lifetime, thereby creating potential problems in connection with disposal. Enter a "yes" or "no" in the second line of the chart.
Then state which type you believe the chemical to be (highly problematical, problematical, or less problematical).
If you find that the substance affects the working environment, put an X in the appropriate box. If you do not know its impact, put a question mark instead.
The three boxes marked "Air", "Water", and "Waste" are used to assess how the substance enters the environment. If you know where the substance ends up, place an X in the appropriate box(es); if you are unsure, put a question mark instead. If, for example, you know that the substance emitted is not emitted into air, put a minus in the relevant box. Once all boxes are filled in, you have linked your previous sorting of the substance (identifying it as type 1, 2 or 3) and your knowledge about its fate in the environment.
The substances which have been identified as highly problematic or problematic and which are also emitted or discharged into the environment pose the greatest potential environmental threat and should be assessed in greater detail. Conversely, substances which are less problematic and which are not emitted pose only a minor threat to the environment.
Example B3.24: Assessment of a substance emission |
|||
Substance: |
Naphtha, hydrogen-treated light |
||
Does the substance follow the product (yes/no)? |
Yes |
||
Type: |
Highly problematic substance |
||
Impact on the surroundings |
|||
Working environment |
Air |
Water |
Waste |
| X | X | - | - |
Chapter 5 presents the semi-quantitative EDIP screening method which you can use to assign
priorities to the substances which need to be assessed in greater detail.
The following conditions for environmental impacts can be used to carry out a rough interpretation of the significance of chemicals in relation to energy generation. For some of the most toxic of the highly problematic substances, the environmental impact of an emission of 1 g into the environment corresponds to the total environmental impact of the production of 1,000 – 10,000 MJ electricity (produced in Denmark). For the less dangerous, but still highly problematic substances, the corresponding figure would be approximately 10-100 MJ Danish electricity, whereas the problematic substances correspond to 1-10 MJ and the environmental impact of less problematic substances corresponds to that of less than 1 MJ Danish electricity.
You should always assign priorities to any substances which you have identified as type 1 substances, as well as any type 2 substances which appear in large quantities. For such substances, you should go on to carry out an actual chemical assessment – see chapter 5.
Under the heading "other", you may have listed a number of different issues for which no specific instructions can be given.
Working-environment issues may concern noise or repetitive work in connection with production. They may involve allergy problems in connection with products that contain nickel, or emissions of solvents associated with certain paints. Ergonomic problems caused by poorly designed chairs may also be an issue.
Other issues might include use of large areas of land in the manufacture of vegetable oils or other, similar products. Energy generation based on waterpower also requires use of extensive areas.
One common feature of the issues listed above is that they are difficult to measure. You will have to make do with looking at these issues in a qualitative manner.
If you believe that the issues listed are significant to the overall impact assessment, or if you have any doubts about their importance, you should contact an expert to get advice on how to continue. See section 3.4.
3.3 Did you get answers to your questions?
You are now about to examine whether the MECO chart for your product(s) gives you the answers to the questions you asked when you defined the goal of your environmental assessment.
First of all, you should go through the MECO chart to see if you should have forgotten anything. If so, you will have to supplement and complete the chart as appropriate. |
It is a good idea to always go through your work with someone else, explaining the various
assumptions you have made. If your company does not have a person with relevant
qualifications among the staff, you will have to consult with someone from outside the
company.
The interpretation of your results and the overall assessment in relation to the objective of your work depends on how your assessment is to be used. This is why it is important to correlate your original goal with the uncertainties associated with the MECO chart.
If the goal is that your work should be used internally at the company in connection with product development, the requirements for documentation will be relatively modest.
Example B3.25: Comparing goals and results If the purpose of the environmental assessment of the coffee maker is to assess the materials used to manufacture it, the MECO chart can provide an excellent indication of where the majority of the raw materials involved are consumed. Here, you will see that aluminium and copper account for the most significant consumption. It should, however, be noted that the relatively high energy consumption entails much greater consumption of energy resources (crude oil). |
Use table 1 in Appendix B to see which materials are regarded as less resource-intensive.
If you want to use a comparison between two products for marketing purposes, thorough documentation is crucial.
An environmental assessment carried out by means of a MECO chart will usually not provide sufficient documentation if the results are to be used externally. In such cases, it is also important to have an external expert review the materials.
3.3.1 Insufficiently clarified issues
If you have many insufficiently clarified questions, or if you feel something is missing, you will have to decide what sort of additional information you need.
It is important to distinguish between issues caused by:
The preconditions Data uncertainty Lack of data
3.3.1.1 Preconditions
If the unclarified issues concern the product and the scope definition established for it, you will have to review the preconditions you made earlier. Perhaps you need to include more.
For example, you may need to find more information about the most common form of disposal for your product. If you do not know what the most common form is, but know that there are two options, you will have to consider both of them. Prepare a MECO chart for both options to assess whether the difference matters.
In other cases, you may face several options. In that case, you will have to establish some assumptions and see what their consequences are by preparing MECO charts – one for each option.
3.3.1.2 Data uncertainty
In order to be able to assess and compare your results, it is important that you carry out an assessment of the uncertainties associated with your results. There are two types of important uncertainties.
One type of uncertainty concerns the various figures measured. This kind of uncertainty will typically appear in connection with inventories of consumption of chemicals or energy. If you know the level of uncertainty, or if you can make an estimate of it, you should use the relevant figures. If you do not know the level of uncertainty, you should assume that all measured figures are subject to uncertainties of 25% and other figures are subject to uncertainties of 50%.
The second type of uncertainty has to do with the type of data you have been able to obtain. If your work has involved use of empirical figures or other figures from literature, variations in relation to your particular product(s) can be very significant. If you cannot assess this uncertainty yourself, you should assume that the figures may vary by a factor of 100%.
3.3.1.3 Lack of data
If you have difficulties in obtaining information about all the materials used to manufacture your product, or if other information is missing, you must try to assess the consequences of leaving out those elements.
For example, your lack of data may have to do with plastics. Most types of plastic are very similar. They are mainly made from oil and gas, the energy necessary to produce them is more or less the same for all types, and they have almost identical energy contents. In such cases, we recommend that you start by considering the total quantities: carry out calculations in the MECO chart to see whether it is important to know the exact type of plastic involved. If the precise nature of the plastic is important, you will need to seek further information – see section 3.4.
3.3.2 Where do you go from here?
You can continue your work in several different ways. The options described in this Handbook are outlined in figure
Figure 3.3
Options for further efforts once the MECO chart is complete
Examples of other possible assessments would be working-environment assessments, workplace assessments or risk assessments focusing on accidents and emissions into the surroundings. These possible types of assessment will not be addressed in any more detail in this Handbook.
Before you make your final decision, you should consult with another person. This could very well be an external person with experience within the area. |
The following contains some instructions which can be used as rules of thumb as you choose
your next course of action.
3.3.2.1 Task complete
If you find that the MECO chart answers your questions with sufficient certainty in relation to the goal definition, your task is complete.
Please note that the MECO chart does not focus on outputs such as emissions and waste. |
The MECO chart is suitable for providing a first indication of the most significant issues
associated with the life-cycle of a given product. It also provides an excellent basis for
choosing between various materials in connection with product development or for internal
information within your company.
Example B3.26: Significant issues in relation to product life-cycles For the coffee maker, the MECO chart clearly shows that the energy consumption is greatest during the use phase, and that this phase is more important than the raw materials phase in terms of resources. |
The MECO chart also shows that transport (primarily of coffee) is very significant to the
total energy consumption.
As regards the raw materials used to manufacture the coffee maker, aluminium and copper account for the greatest environmental load. If the amounts used of these quantities can be minimised, the negative environmental impacts will also be reduced.
If you have the answers you were looking for, you are now ready to proceed to chapter 6. This chapter features recommendations on how to present your work.
3.3.2.2 Further data
If your review of the MECO chart shows that you need more data to describe the system or data about materials and energy, please consult section 3.4. Here, you will find instructions on how to find additional data.
Example B3.27: Uncertain data If the goal of your work is to document the environmental impacts of the coffee maker in operation, the data bases for coffee filters, coffee, and heating as a result of energy losses are all estimated on a rather flimsy basis. Here, more data is called for! |
Once you have obtained the additional data you need, you must enter them into your MECO
chart and once again assess whether you need to continue your work.
3.3.2.3 Model simulations by means of a PC tool
If you want your assessment to be based on calculations of inputs and outputs, you should consider using a PC tool.
It may also be relevant to carry out a model simulation by means of the PC tool if you want to consider various changes to the product. This will make it possible to carry out the calculations in a more efficient manner.
Example B3.28: Product changes and assessment of emissions If you wish to consider alternative materials for the manufacture of the coffee maker, it may be relevant to carry out a model simulation. It may be possible to replace copper and aluminium with other materials, or to use them in smaller quantities. By choosing a different design or mode of production, it may also be possible to separate out the materials and reprocess the metals. The MECO chart showed that use of the coffee maker involves considerable energy consumption. Of the approximately 10,000 MJ consumed in total, half is used for coffee filters and half is used for electricity consumption. Model simulations are also relevant if you wish to assess the emissions and waste quantities generated. |
If the MECO chart shows that a number of chemicals and ancillary materials are
significant, you should carry out a chemical assessment and then later consider whether
you wish to proceed with the PC tool.
Please read chapter 4 before you begin. Reading chapter 4 will make you familiar with a number of issues which you need to consider before making your final choice. |
3.3.2.4 Chemical assessment
If, by following the instructions in section 3.3.1.3, you have found out that chemicals and ancillary materials are significant to your environmental assessment, you should carry out a proper chemical assessment.
Example B3.29: Products where chemical assessment is important
A common feature of these products is that they are made of a number of chemical substances, and that large percentages of the product enter the environment during the use phase. |
It is difficult to provide specific instructions on when it is relevant to carry out
chemical assessment instead of a detailed LCA or as a supplement to a detailed LCA. The
most important parameter for this choice is whether the chemicals in the product can be
expected to have significant negative impacts on human health and the environment in
relation to the raw materials contained within the product itself.
As a rule of thumb, chemical products should be looked at by means of a chemical assessment, as a large percentage of such products are often emitted into the environment (examples include: paint, car maintenance products, household chemicals). |
Please read chapter 5 before you start. It may be crucial to carry out a chemical
assessment, but this can also be very difficult. You should consider having the entire
chemical assessment – or parts of it –carried out by consultants/knowledge
centres.
Once a chemical assessment has been carried out, you may want to proceed by using the PC tool. We recommend that you contact a knowledge centre which works with LCA in order to clarify this issue.
3.4 Find additional data
You will almost always need to seek additional data to supplement those already obtained.
In connection with expansions of the MECO chart, it would be most relevant to seek further information from the supplier of the materials and ancillary materials used. |
If the supplier is also the manufacturer of the materials, you will be able to obtain
excellent information about the contents of a given material or ancillary material. If the
supplier acts only as dealer or importer, you may have to contact the actual manufacturer
instead.
 | For metals, it is important to identify the main component and any added materials. |
| For plastics, it is important to identify the main component, any fillers and other additives as well as any residues of heavy metals and other impurities that may have an impact on the environment. |
| For renewable resources, such as paper made from wood or oil made from plant seeds, it is important to obtain information on which substances and materials are used for manufacture. For example, paper production involves the use of chemicals as ancillary materials, and these ancillary materials account for more than 20% of the weight of the finished paper. |
| In Denmark, the best documentation for chemicals is, generally speaking, a Danish Material Safety Data Sheet. You can requisition such safety sheets (often called MSDSs) from manufacturers or importers. |
| If you need information in connection with the raw materials phase, e.g. information on the manufacture of a metal or manufacture of a particular kind of plastic, you will have to contact a knowledge centre for an expert opinion. |
| Information about energy issues, energy consumption or energy contents in raw materials can be obtained on the Internet. Even so, it will often be necessary to seek advice from a knowledge centre. |
| If you need conversion factors to calculate mPR values, you will have to contact a knowledge centre with experience of establishing such factors. |
Of course, it is always possible to seek information on the Internet. Generally speaking, however, the data found on the Internet will usually not be given in a form which renders them suitable for your purposes.
At the website of the Danish Environmental Protection Agency, you can search for reports and projects which involve life-cycle assessments of one or more products. If one or more of these projects are about your product type, you may find relevant information that way. Some project reports are available at the website (http:// www.mst.dk), while others can be ordered from Miljøbutikken.