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3.5Major developments within standardisation (CEN) and regulation in Europe

3.5.1The European Construction Products Directive (CPD) – 89/106/EEC

The CPD gives the framework and procedures for development of Technical Specifications (TSs) for construction products. It is a 'New Approach' Directive. This means that the TSs are in principle developed by CEN-construction-TCs as Harmonised Standards. For the aspects of attestation and certification the EOTA (European Organisation for Technical Approvals) contributes to the development of Harmonized Standards. The scope of the CPD concerns the phase of use in a construction (houses, industrial buildings, road building, etc). Only the direct risks for users of the building and the direct environment are included. So risks of workers safety, climate aspects, second lifetime of materials, etc, are not included. This is a limitation that will not be followed in the SAMARIS project as the entire life cycle of a material is of relevance. Six types of essential requirements are covered by the TS's. Essential Requirement 1 deals with mechanical resistance and stability. Essential Requirement nr. 3 focuses on 'Hygiene,. Health and Environment'. The other requirements of less relevance here are ER 2: fire safety, ER 4: safety in use, ER 5: noise and ER 6: energy.

After publishing of a TS, products may only be brought on the market with a CE-mark, with which is declared that the product is produced according to the specifications of the TS.

In a TS is listed which parameters are relevant for that product. Test methods are given with which these parameters should be tested. In general no limit values are given in the TS itself. The producer should inform the client about the level he measured. In the TS, classes of performance levels may be defined, so the producer can state that his product meets the requirements of class 2 or class 3 of a certain parameter.

This means that the national legislators, local authorities or the users of construction materials can define their limit values for the parameters that fall under the scope of the CPD. But only for the parameters that are included in the TS and only on the bases of test methods that are included in the TS. This will limit the freedom of the national authorities to set environmental demands in their legislation. The preference in Essential Requirement 3 for release will also mean the evaluation of construction products will have to change in many cases from content to release.

Within the field of construction products about 40 product families are distinguished (such as concrete products, road construction products, aggregates, doors, heating appliances, etc.) TS are developed for a product family or as usual only subfamilies. In total about 300-500 different TSs will be developed. The others will follow step by step. In those TSs all essential requirements are included now, except the 'dangerous substances' form requirement 3. It turned out to be too complicated and too time consuming for the construction sector to include these into the TSs, without further delay. Last year (2003) the Commission (DG-enterprise) started a working program on completing the TSs with dangerous substances. The first step was an inventory of the national and European legislation, with limit values and test methods on dangerous substances, that (also) are related to construction products and that fall under the scope of the CPD. These substances are also called 'Regulated Substances'. The next step will be to select the relevant substances and to define which kind of test method should be harmonized and how a selection should or could be made for each Technical Specification. Based on this selection a mandate will be given to harmonize these test methods and to include them into the next generation of Harmonized Standards. It is recognized that it still will be difficult to organize this standardization in a proper and practical manner. So initiatives are taken to develop a horizontal standardization within CEN for these test methods for the whole construction sector. A recent development worth mentioning is a workshop organized by CEN Construction in cooperation with CEN Environment in Coimbra (Portugal) on 29 and 30 of September 2003 (http://www.cenorm.be/cenorm/workarea/sectorfora/construction+sector+network/conference.asp). This meeting was held to coordinate test development for construction materials, as there are many (obvious) analogues between the release mechanisms of construction materials, recycled materials and waste materials.

3.5.2The Dutch building materials decree (BMD)

The Dutch Building Materials Decree (BMD, 1995) is the first regulation addressing environmental issues of construction materials. It is based on the laws for protection of soil and protection of surface water. So this decree gives quality criteria for the use of stone building materials and earth used as a construction material. There is no difference made between primary materials, secondary materials and use of waste materials.

The decree sees only to these materials as far as they are used in contact with rain, surface water and ground water. (E.g. in embankments, road building, outside walls of buildings, foundations and roofs) Not all environmental aspects are covered, but it has proven to be an important element in judging the environmental quality of construction materials. The question ‘give criteria’ was simple. The answer turned out to be complex, in which a great number of aspects had to be considered and a great many tools had to be developed, checked and thoroughly discussed. On the other hand practical choices had to be made, to prevent an unclear situation continuing too long. After an introduction period of 3 years, the decree has been in full operation from 1 July 1999.

Primary, secondary and waste materials.

In the BMD and in many other environmental regulations there is no distinction between these three ‘types’ of materials. All those kinds of materials have to meet the same standards. In general there is no difference in the way those different types of materials are tested. If the matrix of materials is quite the same, the same testing procedure can be used for examining the quality of the materials, independent of the status ‘primary’, ‘secondary’ or ‘waste material’. After going through such a test, a conclusion can be made whether a material can be re-used, treated, or disposed of.

For secondary materials it is important that they are dealt with in the same way as primary materials. This is the only way to provide opportunities in marketing them in the construction industry. It is important that e.g. in standardisation documents, legislation, etc., no discrimination is made in the use of primary or secondary materials or waste materials. When the materials meet the basic quality criteria, it must be possible to utilise them.

In general, there is only one specific place where differences are made in primary, secondary and waste materials, namely in waste management acts and regulations. In those regulations the difference between these terms is mainly based on the question if and how waste materials need to be managed and controlled to be sure they are properly handled. After adequate treatment and testing most of these materials can be finally re-used as normal materials.

General soil protection standard setting

In the complex matter of standard setting in soil protection some main points can be mentioned which were important for the development of the BMD. Soil protection policy is based on the principle of “multi-functionality of the soil”. A clean soil should be kept clean and a polluted soil should not be polluted any further, but improved as far as possible.

'Target values clean soil’ are a reference for a clean soil. These values are based on data of unpolluted soil and data of negligible risk for human exposure and ecological quality.

‘Intervention values’, beyond these target values, have also been developed, especially for the judging of soil pollution. When the level of a pollutant exceeds this intervention value, restorative measures have to be taken within a short term.

General policy on standard setting in soil prevention decrees

As mentioned the target values and also the intervention values have been based on risk assessment. Pollution of the soil should be as low as possible, and when possible without any burden to the soil at all. If this is not possible and the activity cannot be forbidden (for social or economical reasons), according to the general soil protection policy, the load into the soil should be ‘As Low As Reasonable Achievable’ (ALARA). In fact ALARA means ‘by using state of the art technology’. The quality of the soil on which the action takes place does not influence this basic principle. So on polluted soils the environmental load should be equally minimised.

If for a certain activity pollution cannot be avoided, often a maximum level of the burdening of the soil is defined or certain preventive measures are demanded (Walthaus and Ruardi, 1998).

As far as possible these levels or measures must be determined in such a way, that it may be expected that the quality of soil/sediment and groundwater will not exceed the target values because of the burdening, in the long term and the short term. The use or re-use of materials should not result in creating new locations with a polluted soil which should have to be cleaned up afterwards.

Standard setting in the BMD; inorganics

A maximum level for release of inorganic substances from construction materials was based on these principles. This level was developed as an ‘immission value’. A ‘marginal burdening’ is excepted when the immission does not exceed a calculated level of 1% of the concentration of the target value of an inorganic substance in 1 meter of the soil, within 100 years. With this approach it is expected that the sediment and the groundwater are sufficiently protected and the use of most of the primary and secondary materials remains possible. For a number of materials a technical improvement is required for the continuation of the use of these materials.

For inorganic substances no maximum concentration levels have been defined. It is expected that construction materials will not be mixed with the soil during construction and during use in the construction. Otherwise limiting the concentration should be important in preventing the soil from being polluted.
Polluted soil/sediment may be (re-)used as a ‘construction material’, e.g. for embankments or road construction. If polluted soil is used it has to meet the immission levels (marginal burdening) and the concentration of inorganics and organics have to remain below certain maximum levels (mostly below the intervention values.). A maximum concentration level is felt as necessary, because there is a greater risk that after a certain time the polluted soil becomes mixed with the surrounding soil. The maximum concentration value is also felt necessary to prevent the creation of new area with severely polluted soil.
Organic substances

At this stage, only maximum concentration levels have been defined for organic substances.

The development of test methods and the insight in release mechanisms have not yet advanced as far as it has for inorganics. For volatile organics it has been proved not possible to develop useful test methods. The speed of release is too dependent on the local situation. In the end often, the complete content of volatile organics may be released. And moreover, during sampling and testing a great deal of the organics may disappear, so the results will not representative.

In general only a small number of non-volatile organics can be expected to be present in only a small number of construction products.

In future, when technical developments of tests have reached an acceptable level, it could be considered to add these release tests to the regulations, only for a selected group of organics. For other organics only a test on the total amount remains possible.

It also has to be taken into account that for some organics, as PAH, there are other environmental regulations on dangerous substances limiting the maximum content of the organics. So it has to be carefully examined if it is useful to introduce release tests for organics to the BMD and other regulations.

Emissions are measured in the laboratory by means of some advanced release tests; a column test for granular material and a diffusion test for moulded materials and for monolithic materials. It has proven to be too expensive, too complicated and too time consuming to test materials in field situations. So some formulae were developed to make a connection between the emission test results and the maximum immission values.

With these formulae it is possible to make some distinction between products in thick layers and products which are used in thin layers, for which the acceptable emission levels are higher. It is also possible to make a distinction between products, which can come into contact with water and products used in isolated conditions. In these isolated conditions, the normal characteristics of certain suitable constructions (e.g. asphalt roads) are used as an isolation cover (infiltration reduction), in combination with additional technical measures, such as a minimum distance above the ground water table.

Tools for testing

As earlier mentioned a lot of attention had to be paid to the test methods and the standardisation of these methods. With the Netherlands Standardisation Institute (NNI) a lot of work has been done to realise an adequate set of testing procedures (NEN, 2004). Conditions for these methods were:

- Giving adequate information about release or content of substances.

- Measuring on a level that could meet rather low concentrations, as necessary in relation to the maximum permitted emission levels.

- Unambiguous test results.

- A good performance repeatability and reproducibility.

It proved to be necessary to pay attention to the complete testing procedure, from sampling till reporting the final data.

For this purpose, a modular system of test methods has been developed.

The results of release tests are expressed in a load: in mg/kg when using column tests or in mg/m² when using diffusion tests. It is namely not important to use the concentration in the eluate, because that concentration just depends on the quantity of the eluate that is being used at that moment. When one knows the release load, a better relation can be made with the soil protection criteria as mentioned above.

A number of basic characterisation tests have been developed in this way. Some of them have been chosen for general judgement of products in the BMD, because when using these basic tests a judgement can be made for a wide range of products. For daily tests in production circumstances, simplified compliance test procedures for individual products may be used, if they have been worked out and checked in a certification procedure.

As far as felt necessary, users of construction products can use simple acceptance procedures or tests for a quick scan when they receive the materials on the building site. But, if available, certificates will be the first step in acceptance procedures. However, if a user or a competent authority wants to do an ultimate check, it is necessary to use the general judgement test, which may be expensive and time consuming. So it is preferable if one can rely on certification procedures.