Arbejdsrapport fra Miljøstyrelsen 41/2006 – Handlingsplan for 'Heavy Duty' branchen

Handlingsplan for 'Heavy Duty' branchen

Summary and conclusions

A survey of the heavy-duty sector

The scope of the present work is to identify how occupational health can be improved and environmental impacts can be reduced in the heavy-duty sector and to propose suitable development projects supporting these improvements. The heavy-duty sector produces large steel constructions like wind turbines, bridges, factory buildings and ships.

There is overall growth in the sector, mainly due to increasing construction activity and because of the booming market for wind turbines. Turnover for the sector is estimated at EUR 2 mill per year. The value of buildings and constructions protected by the heavy-duty sector is estimated at EUR 7 billion .

Anti-corrosion protection may be performed indoors in large workshops or outdoors with or without shelter. Before coating, surfaces are cleaned of rust, scale and previous paint layers. There is a risk of pollution with dirt and dust from these cleaning activities. Subsequently the steel is coated, typically with solvent-borne products, implying a risk of VOC-emissions. Moreover the coatings are frequently epoxy- or polyurethane-based, thus presenting an occupational health risk as well.

There is much manual work in the sector, and handling of dangerous coating materials often requires personal protection equipment like gloves, masks or even full protective garments with external air-supply.

The survey has shown that the most serious problems in the sector are emissions of solvents, dust and blast media (sand, grit etc.) to the environment and employees being exposed to solvents and other hazardous substances.

According to the EU VOC Directive, the sector is obliged to reduce future emissions of solvents. To achieve this, contractors must apply coating materials with reduced solvent content, use less solvent-borne coatings or find alternative coating materials.

Suitable projects

Several development projects relevant to the sector have been identified - projects that may reduce environmental impacts and occupational health risks. The different proposals have been evaluated with particular regard to their environmental and occupational health potential and their degree of originality.

Some proposals deal with comparison of different blast cleaning methods regarding their efficiency and cost. However relevant, these projects are considered too specific to fulfil the demands of the entire heavy-duty sector. Another idea is to investigate how blast media contaminate during use; but work in this area has already been initiated elsewhere.

Another idea is to investigate the efficacy and costs of alternative blast cleaning media. This no longer seems appropriate as an alternative has already been found (“Carbogrit”), and this has been studied and introduced on the Danish market.

Investigation of the efficacy of manual tools for cleaning operations has been found too specific to justify public support.

Summing up, several ideas have been presented that either are too specific or which do not seem to possess sufficient environmental or occupational health potential. Three ideas however have passed this initial screening:

- a mobile platform with an enclosure for blast cleaning and coating e.g. of steel ships

- automised paint application on towers for wind turbines

- information for consultants on environment-friendly coatings alternatives

Suggested development projects

Two projects – a) mobile platform for blast cleaning etc. and b) automised paint application on wind turbine towers - have been compared and their environmental and occupational health potential evaluated. The conclusion is in favour of the project on coating towers for wind turbines. This project seems to have the best potential to reduce emissions and consumption of resources. Accordingly, this project is suggested as a development project for the heavy-duty sector.

In addition, it is suggested that an information project be initiated to inform professional consultants about alterative coating systems with less environmental and occupational health impact than traditional systems.

For both projects more detailed project descriptions are presented. Development of automised paint application assumes active participation from an industrial manufacturer of turbine towers, from manufacturers of paint application equipment, paint manufacturers, paint contractors and an advisory body. It is intended that development be divided into a) laboratory or pilot scale experiments with application principles, and b) development of a full-scale plant.

The information project is suggested as an unofficial annex to EN/ISO 12944 - Corrosion protection of steel structures by protective paint systems. This standard presently offers a very limited choice of coating systems from an environmental and occupational health point of view.

It is intended that the annex contain a comprehensive list of examples of coating systems that take into account environmental and occupational health aspects.