| Front page | | Contents | | Previous | | Next |

Miljøvurdering af kemiske stoffer i byggevarer

Summary and discussion

The building sector uses numerous products (several thousands) many of which contain chemicals, some have harmful effects on human and environmental health. Due to the limited access of data the impacts of chemicals can be overlooked, e.g. in eco-profiles of building elements. The reason is lack of product-specific emissions by manufacturing chemical products, e.g. waterproofing systems and sealants. Besides, most LCA models do not include assessment of emissions in working environment, indoor climate or from disposal processes.

The aim of the project

This project aims to adapt an existing method for assessing chemicals and test it on selected construction products. The method should use easily available data, e.g. produced in environmental declarations of construction products, and include the whole life cycle of the materials. However, this project will focus on important life cycle phases, indoor climate and disposal.

The project gives an overview of simple existing methods and discusses their suitability for assessing chemicals in construction products. One method is adapted and then tested on waterproofing systems. Waterproofing systems are recommended for different types of bathrooms, and many products are available some containing dangerous substances. An assessment of chemicals together with eco-profiles of building elements can supplement technical information already available for the different types of bathrooms.

Methodologies

The amount of specific hazardous categories, (e.g. type 1, 2 and 3 or unwanted, problematic or non-problematic) can be used as indicators of potential impacts from chemicals. The methods give results for building elements or buildings that are easy to communicate, but some detailed information is lost. All substances in the same category contribute equally, and special properties of some substances are not considered.

The project uses two score methods, EURAM (European Risk Ranking Method) and EDIP screening method (Environmental Design of Industrial Products), both using a score for exposure and effect, and then multiply the scores.

EURAM was used to rank high production volume chemicals, which afterwards went through a risk assessment. The principles for calculating scores according to EURAM were adapted to construction products.

Score for exposure in the indoor climate was calculated from the amount of substance used, as emissions from construction products cannot be calculated from the properties of the substances (vapour pressure/boiling point, octanol-water partition coefficient). The effect score was based on odour detection limit. According to EURAM the score for human health was based on the classification of hazardous substances (Risk phrases).

Score for exposure from disposal of products was calculated from the amount of substance used and some properties (vapour pressure/boiling point, octanol-water partition coefficient, and biodegradation). The effect score was based on the aquatic toxicity (LC₅₀) for water organisms as in EURAM.

The EDIP method based the score for exposure on qualitative criteria (expected emission, biodegradability and accumulation potential), and score for effect was based on the classification of chemicals (Risk phrases).

Score methods give figures for the impacts from chemicals but it is important to give an overview of parameters and how the scale for these parameters are defined, see table 3.

Table 3.
Score method parameters.

Score methods were developed to assess complex problems with many parameters in a standardized way that gives easily understandable results useful for documentation of buildings when comparing alternatives. Often the comparison is made on a subjective basis with no documentation of which parameters have been included.

The disadvantages are that detailed information is lost, but it may be possible to get background information about the included parameters and the scales used.

Waterproofing systems and eco-profile of bathroom walls

There have been many problems with waterproofing of bathrooms, and consequently several types have been developed and some have recommended use of waterproofing systems. The systems consist of a primer and a membrane. Information about waterproofing systems has been collected from product information sheets and safety sheets. Some primers contain organic solvents and one contains chlorinated paraffins, but the safety sheets give information only about dangerous substances above a specific level, and it has not been possible to get complete compositions of primers and membranes. In addition, the safety sheets only provide information about chemicals in a product, but chemicals in two-component products may react and therefore pose no risk of impacts in the indoor climate and the disposal processes.

The mentioned score methods assess chemicals in two waterproofing systems, one with a two-component epoxy primer and one with an acrylate primer, both with an acrylate membrane. The two-component primer contains several dangerous substances, and the acrylate primer contains some organic solvents.

Results

Indoor climate

Modifications of EURAM show that it is difficult to use the method due to lack of data on emissions and odour detection limits. Therefore the exposure score is based on the amount of chemicals used and default values for the odour detection limits, but for two-component primers the results did not provide a good indicator for impacts from chemicals as default values are used for nearly all the components.

Disposal

The results from the adapted EURAM show that it is possible to make an assessment of the chemicals in products, but for two-component products the chemicals may have reacted to other substances.

Concluding remarks

Today eco-profiles do not include all important potential impacts from chemicals because environmental data for chemicals are incomplete. Furthermore, LCA models most often do not include life cycle phases where chemicals may impact, e.g. indoor climate and disposal. Therefore, it is necessary to develop other assessment methods for chemicals.

From the application of different methods it can be emphasized that very simple methods should be used so long as life cycle assessments do not include impacts in the indoor climate and from disposal due to lack of data and models. At present it may be possible instead to list substances or to indicate the amount of specific categories of substances. However, efforts to obtain more data on chemicals and to develop generally accepted score methods should be intensified.

Experts on human health and the working environment have criticized the methods for being too simple for assessing impacts in the working environment and indoor climate. Detailed information about the amount and type of chemicals in products is necessary for the assessment of impacts in the working environment. For the indoor climate the labelling of more products should be intensified, and the results from the labelling should be utilized the LCA.

Figure 1.
The figure shows the possibilities for selection of methods. The method calculating the amount of hazard categories is recommended, so long as there is a lack of data and models for the different phases in life cycle assessments.