Nanomaterials: The Next RoHS Target?

A proposal for the RoHS Recast called for several provisions to apply to nanomaterials, including notification requirements and an outright ban on nanosilver and long multi-walled carbon nanotubes. Although the proposal was accepted in the first draft of amendments considered by the European Parliament’s ENV Committee, it was rejected entirely by the final version. Nanomaterial stakeholders and the manufacturers that rely on them have nonetheless been left in a gray area. What does this reveal about how RoHS functions?

What Is RoHS?

RoHS, shorthand for the European Union’s Directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment, came about in the first few years of the new millennium. It was designed to address the risks associated with the use and disposal of electrical and electronic equipment, which tends to contain materials and substances that are hazardous to human health and damaging to the environment.

Some of these materials we know a lot about; others we know little about; and some are yet to be uncovered, as scientific understanding of dangerous substances expands and manufacturing techniques for electronic equipment evolve rapidly. For this reason, the eventual expansion of the Directive’s scope and content was built into its very language. Such an edit or expansion of the Directive became known as a “recast.”

Within the first decade of the Directive’s implementation, the European Commission proposed a variety of amendments, and nanomaterials were the focus of several potential new provisions. This article starts with the basics of RoHS itself before turning to nanomaterials and the nuances of this particular recast.

How RoHS Works

RoHS is an EU directive. In the words of the EU itself, a directive is “a legislative act that sets out a goal that all EU countries must achieve. However, it is up to the individual countries to devise their own laws on how to reach these goals.” RoHS works in tandem with another directive, the Waste Electrical and Electronic Equipment Directive, or WEEE. Together, they address the entire life cycle of electrical and electronic equipment.

You can think of WEEE as a set of goals for the disposal of such equipment, which usually comes down to collection, recycling, and recovery initiatives. RoHS, on the other hand, is a set of goals for the manufacturing of the equipment, limiting the quantities of harmful substances that go into the product itself. The products covered by RoHS and WEEE span a wide variety of items, including household appliances, toys and sports equipment, electric construction tools, computers, phones, light bulbs, and video recording devices.

When RoHS came into effect in July 2006, it restricted six substances, including lead, mercury, and cadmium. Since then, a handful more have been added to the list. Interestingly, the Directive doesn’t fully ban these materials. Instead, it sets concentration limits for each substance (how much can be put into a product before it is considered unsafe and therefore non-compliant) and lists cases in which a product is exempt from those limits, for example where substitute materials would be unreliable or more hazardous. For a sense of scale, in 2010 there were some 40 application exemptions, including for certain medical devices and military instruments.

Maximum Concentration Values and “Homogeneous Materials”

The safety threshold for a particular substance is known as its maximum concentration value (“MCV”), expressed as a percentage by weight. While a quantified maximum can sound like a hard limit, there is quite a bit of wiggle room in how it applies. This is partly because the MCV applies not to the entire product, but to each “homogeneous” material separately. The European Commission defines a homogeneous material as “a material that can not be mechanically disjointed into different materials.” Think of it this way: if a material can be physically taken apart by unscrewing, unsewing, cutting, crushing, and so on, it is not homogeneous.

If that sounds a little vague for a definition that determines applicability, that’s because it is. EU member states can (and will) interpret the definition slightly differently. This is part of the wiggle room in determining RoHS compliance, and it compounds the variation among member states as they develop their own implementing legislation. The EU has made some efforts to clarify uncertain points through guidance documents, but these have no binding power.

The Recast and the Nanomaterials Proposal

The Recast followed a European Commission proposal containing a variety of amendments to RoHS. The proposal included an expansion of scope under which all electronic devices would be covered unless indicated otherwise. That would essentially lower the overall number of exceptions and prompt more critical discussion of why a device should be exempt. Another key amendment, and the focus of the rest of this article, was the proposed ban on certain nanomaterials, specifically nanosilver and long multi-walled carbon nanotubes.

Spoiler alert: in the end, neither was banned. What’s significant is that the nanomaterials debate may be the basis for future legislative initiatives, and that it exposes the gray area created by the ENV Committee’s adherence to the precautionary principle.

The European Parliament’s Committee on the Environment, Public Health and Food Safety (the “ENV Committee”) issued its final draft report on the Recast in June 2010. The Committee had determined that provisions for nanomaterials were necessary, citing, as Cana and Bergeson summarize:

[T]he “scientific uncertainty” these materials pose to human health as well as environmental risks; the lack of internationally harmonized definitions or agreed test guidelines; and “Increasing scientific evidence” that certain types of carbon nanotubes have in certain circumstances inspired reactions similar to that of other durable fibers, including asbestos.

The report went on to propose a definition of nanomaterials (materials generally understood to have an average particle size of between 1 and 100 nanometres). It set out notification and labeling obligations, essentially making operators responsible for labeling products that expose consumers to nanomaterials. As for nanosilver and long multi-walled carbon nanotubes, the ENV Committee recommended banning them from electrical and electronic equipment entirely.

The European Parliament revised the Recast several times over several months. By the final review, those provisions (the bans on nanosilver and long multi-walled carbon nanotubes, and the labeling and notification obligations) had been dropped.

The Precautionary Principle and Its Limits

The conversation around the proposal is what matters. RoHS is driven by the precautionary principle, the formal version of “better safe than sorry,” which lets decision makers act and legislate with a focus on prevention rather than finding solutions once it’s too late. That mechanism makes a lot of sense for directives like RoHS, whose purpose is to preserve and protect, but nanomaterials show how nebulous it can become. The justification for considering an outright ban on these nanomaterials (quoted above) rested heavily on precaution: we have reason to believe these materials are hazardous.

But the ENV Committee didn’t specify the actual hazard to be prevented or rely on concrete scientific findings. It was fully within the Committee’s prerogative to base recommendations on scientific uncertainty alone, which is why its final draft did include the intention to ban specific nanomaterials, among other provisions. Yet this logic of uncertainty is part of what eventually led to those provisions being eliminated.

The final version of the Recast reflected this gray area within RoHS. Without a specific hazard identified by scientific evidence, it is difficult to justify or implement concrete bans and restrictions. But it also disadvantages manufacturers (and, here, nanomaterial stakeholders), leaving them little to work with when proposing solutions or substitutes. The result is something of a standstill: the ENV Committee’s lack of commitment doesn’t encourage manufacturers to adjust their production, let alone invest in innovative alternatives.

The Door Left Open

That said, the door has been left open for a future reassessment of nanomaterials in electrical and electronic equipment. Notes from a European Parliament plenary session in November 2010 included the following on the RoHS Recast:

As soon as scientific information is available, and taking into account the precautionary principle, the restriction of other hazardous substances, including any substances of very small size or internal or surface structure (nanomaterials) which may be hazardous due to properties relating to their size or structure, and their substitution by more environmentally friendly alternatives which ensure at least the same level of protection of consumers should be examined.

For what it’s worth, there were no other mentions of nanomaterials in the final notes. Again, not much to work with, especially for nano stakeholders.

The ENV Committee’s pivot on nanomaterials may well have been driven almost entirely by concern about the massive impact its provisions would have had on the European market and economy. Still, it’s important to remember what RoHS and its fellow environmental directives are trying to accomplish. Their goal is not to feed economic growth, protect producers’ investments, or keep manufacturers’ costs low. Their goal is to protect consumers and the environment from hazardous materials.

Is it not better to be safe than sorry? See RoHS tracking inside MatCheck, or see Rumzer's compliance engineering services for help watching how this gray area develops. Read the RoHS 10-substances explainer for the substances that did make the cut.

Sources

1. Ruxandra Cana & Lynn L. Bergeson, "RoHS Recast: How Did Nanomaterials Fare?," 7 Nanotechnology Law & Business 380 (Winter 2010).
2. European Union, "Types of legislation." https://european-union.europa.eu/institutions-law-budget/law/types-legislation_en