European regulations aimed specifically at limiting emissions of volatile organic compounds (VOCs) from coatings have been mainly confined to decorative paints and the manufacture of the coatings themselves.
The last piece of major European Union legislation targeting VOCs was the decorative paints regulation dubbed Decopaint, which in two phases from 2007 and 2010 decreased the VOC content of certain coatings by over 90 percent.
The European Commission, the EU executive which is responsible for drawing up new EU legislation for approval by the European Parliament and EU governments, appears to have abandoned tentative plans to extend VOC limits to other coatings sectors, especially industrial paints.
It has also put aside plans for regulations on interior air quality (IAQ) which would probably trigger not only tighter restrictions on VOCs in decorative paints but also in wood coatings on flooring and furniture and in plastic coatings in household appliances.
Nonetheless producers of industrial paints, especially anticorrosion and protective coatings, have been feeling under pressure to reduce the VOC emissions from their products.
They are being pushed by other legislation not specific to VOCs, new guidance from standards organizations, by customers or by their own environmentally friendly strategies.
“(We’re) not waiting until the last minute for legislation to show the way,” said Dimitris Likouressis, group marketing manager at Hempel of Denmark. “We are trying in all our developments to explore ways of combining high performance competitive products with the least impact on the environment. We need (also) to understand that our customers with their own sustainability policies have every intention to work for a safer environment.”
NORSOK, the Norwegian organization that sets international bench marking standards for the North Sea oil and gas, energy and marine sectors, has just been tightening up its VOCs and other rules. Certain water tanks now have to have solvent-free coatings under NORSOC.
Among non VOC-specific EU regulations the biggest influence on solvents usage is being exerted by REACH, the region’s legislation on the registration, evaluation and authorization of chemicals.
It requires that all chemicals manufactured or imported in quantities of 10 tons or more a year will have to be registered with data about their derived no effect levels (DNELs). These show the extent of exposure to a substance below which no adverse effects are expected to occur. The REACH definition of DNEL substances include VOCs.
Manufacturers of industrial coatings are steadily moving over to low-solvent or solvent-free products. “We’ve seen growing interest from our customers for lower VOC alternatives,” said Mary Rose Correa, industrial market manager for Dow Coatings Materials.
International Paint, the marine and protective coatings division of AkzoNobel, has reported that ABB, the global leader in power and automation technologies, had recently awarded it a coatings supply contract for transformers in which a priority was a reduction in VOC emissions.
International Paint has a wide range of VOC contents in its paints—extending from virtually zero to over 400 grams per liter. In discussions with ABB before the award of the contract International stressed that VOC emissions were not necessarily linked to VOC content.
“While VOC per liter is important it is also essential to understand the relative volume solids content of the coatings, the total dried film thickness (DFT) of the applied film coating system and the overall VOC released per area painted,” said Jamie O’Brien, worldwide power market manager at International.
Hempel has just introduced a new solvent-free epoxy coating for the interior of storage tanks and pipelines, specified for temperatures up to 93°C (200°F), which enables oil and gas companies to store and handle high temperature crude oil and water without risk of contamination.
The coating with the brand name Hempadur 35900 does not release VOCs during application so that it conforms with strict environmental regulations such as those of California in the US and the new NORSOK standards.
“It was quite a challenge conforming to the NORSOK standards because it took nine months of testing according to NORSOK requirements,” said Kunal Nadkami, Hempel’s group oil and gas segment manager. “It was particularly demanding for solvent-free coatings, which had to show that they operate at high temperatures.”
Hempel believes that the trend to low-VOC emissions or VOC-free paint in sectors like oil and gas will extend to other coatings segments.
“There is a strong momentum behind the move to low or solvent-free anti-corrosion and protective coatings in oil and gas production, both off- and on- shore,” said Nadkami. “The large players in the market are taking the lead on the issue. They are taking on the responsibility of ensuring that the coatings they use have both a high level of performance and are environmentally-friendly.”
The formulation of anticorrosion and protective paints with low VOC contents can be technologically challenging to coatings producers, particularly if their performance has to be at least equivalent to that of solventborne products.
The durability, hardness and chemical and UV resistance of protective solventborne epoxy coatings can be difficult to replicate in low-VOC paints. Dow Coating Materials has recently introduced waterborne systems with very low VOC contents, which it claims rivals solventborne properties.
One option when switching to low VOC formulations with epoxy coatings is to use liquid instead of solid systems. But while these give high levels of hardness they can also have less flexibility than the solid epoxies.
Poor gloss and foaming can present problems in low-VOC protective coatings, requiring the use of new types of deaerators or defoamers.
At a time of slow economic growth and low capital investment, the move away from solventborne anticorrosion and protective coatings may be a gradual process in Europe because of the necessity for expenditure on new equipment for applying more environmentally compatible paints.
“This is now a trend,” said Nadkami.” The technology, which is now showing itself to be suitable for the oil and gas sector will be suitable for other sectors. At the moment the oil and gas sector and to some extent the marine segment is driving this extension into other segments.”