The final stages are now being reached in the implementation of the European Union's new regulatory controls on emissions of volatile organic compounds (VOCs) in the manufacture and application of coatings and related products.
Yet there are still doubts among coatings producers and their raw material suppliers about what changes to make to paints in order to comply with the restrictions.
Furthermore, there are mounting concerns about the extra costs of carrying out reformulations and of developing and producing raw materials to ensure that coatings have low or VOC-free contents.
The uncertainties seem likely to continue even beyond the time the regulations come fully into force. The European Commission, the EU's Brussels-based executive, is already making preparations to conduct a review of the VOC legislation to see whether it needs to be broadened in its scope and whether the limits should be tougher.
The legislation comprises two directives, which have had to be incorporated into the national laws of the EU's 27 member states. The VOC solvents directive, which was approved eight years ago in 1999, is aimed at reducing industrial emissions of VOCs. The Decopaint directive, approved in 2004, limits the use of organic solvents in decorative paints and varnishes and in vehicle refinishing products.
In October 2007 the solvents directive becomes applicable to all industrial installations after a period in which only new installations have to comply with it.
At the beginning of this year the first stage of the Decopaint legislation came into force. But crunch time will be in 2010 when much more severe limits for many decorative paints will have to be implemented.
"The controls being brought in this year can in most cases be met with relatively small reformulations but the limits being imposed in 2010 will for many paint producers require much more radical action," said an executive at one coatings manufacturer.
Despite knowing for several years about the EU's plans for sharp reductions in emissions of VOCs from coatings, a lot of paint companies appear to be still undecided about how to become VOC compliant.
The Decopaint controls on interior paints will be especially tight. The solvent content of matt paints for interior walls and ceiling will have to be reduced approximately 13 fold from 400 grams per litre in 2007 to 30 g/l at the beginning of 2010. Even the amount of solvents in waterborne paints will have to be cut by over half to the same level.
For glossy interior paints, the limit for solventborne paints will go down from 400 g/l to 100 g/l and for waterborne from 150 g/l to 100 g/l.
With interior and exterior trim and cladding paints on wood and metal, the reductions will be less substantial. For solventborne, the required cut will be one third to 300 g/l compared to one of 13% for waterborne to 130 g/l. With exterior paints on walls of mineral substrates, the proportion will be greater for waterborne-40% to 40 g/l against only four percent for solventborne to 430 g/l.
With decorative coatings with effect pigments, which are becoming more popular, the decrease for solventborne will be 60% to 200 g/l while for waterborne it will be only 30% to the same level.
"There is now a real sense of urgency among coatings manufacturers about sorting out what they will have to do to comply with the 2010 limits," said Edward Appleton, manager for brand marketing activities at Rohm and Haas in Europe.
The two options for coatings manufacturers to keep within the limits is to switch to low solvent, high solid paints or to waterborne. In some categories of paint, such as those for exterior walls, the choice will be easier to make than with others.
"In some areas where climatic conditions, temperature and humidity can be difficult, especially during the winter, it can be very difficult to work outdoors with waterborne coatings," said Jacques Warnon, technical director at the European paints and inks trade association (Cepe).
For raw material suppliers the challenge is to provide binders, pigments and additives which can help to meet the new VOC limits without sacrificing performance.
"Professional decorative painters seem to be worried about several performance issues with waterborne in comparison to solventborne paints," said Appleton. "They are concerned about 'open time' or differences in drying periods between the two so that they may have less time to get the finish they want. Also with waterborne, they may have to do more pre-treating of surfaces. Other concerns are the loss of gloss in waterborne paints and poorer adhesion to substrates."
Rohm and Haas has recently introduced in Europe binders for VOC-compliant paints which focus on high performance. They include low-VOC acrylic gloss binders which have good block resistance and wet adhesion to alkyds and high levels of gloss retention.
BASF has developed a water-based alkyd-acrylate hybrid binder which provides a high gloss surface similar to that given by solvent-based alkyd resin coatings. Furthermore the new binder in exterior coatings is particularly resistant to weathering and dirt.
In the longer term coatings producers are anxious about how much more they will have to pay for raw materials which will be needed to obey the tougher VOC controls.
"It looks likely that some raw materials will be more expensive if only because of the extra R&D costs," said Warnon.
A study on the Decopaint directive funded by the European Commission found that initially the additional R&D costs of developing resins for low or VOC-free paints would average approximately €45,000 ($62,000) per resin. It estimated that resins would become 1.3 – 2 times more expensive, costing coatings producers an extra ?211 million. For paint manufacturers reformulation costs would amount to an average of 0.4% of sales.
However the authors of the study claimed that the extra costs would gradually decline once the new limits come into force. Larger coatings companies would benefit from economies of scale so that the additional costs for them would be relatively modest.