Product Environmental/Health Safety and Performance Metrics

How do you know if you’re doing a good job at work? Your boss or your customers will tell you. While sometimes no news is good news, I always prefer to be told directly: “Mike — you really messed up here” or “Good job, Mike.” Most ways of measuring performance are subjective, such as “good” versus “bad,” and “meets” versus “does not meet.” We need to agree upon ways to measure it in a consistent and comparable manner. So (often subjective) in-house or third-party standards are developed. And even if it is not fair, at least everyone’s performance is theoretically measured using the same yardstick, right?

For product environmental and human health safety there continue to be few metrics consistently and broadly in use beyond “yes/no”:

We like the “yes/no” approach because it is absolute and that makes knowing what is required determinable — if not easy — so we can be sure that what we implement is compliant. Unfortunately many aspects of a product’s environmental and health performance and resulting safety are not so unambiguous.

For instance, consider separability of dissimilar or incompatible materials which cannot be reused or recycled unless they are separated. Electronics examples can include

  • A battery fastened to a product with bolts and/or adhesive
  • A metal nut embedded in a plastic enclosure
  • EMI shielding gaskets that are comprised of metal and elastomeric layers, or conductive metal particles embedded in polymers
  • Copper and fiberglass-reinforced epoxy substrate layers in printed circuit board laminates

The different items and materials in these examples are all technically “separable,” but just how separable they are differs; equipment, materials and expertise to separate them can be defined but that alone won’t tell us how they compare. Why do we want to separate them? Is it for value recovery? Material recovery? Pollution prevention? Reuse?

At a very high level, we want to keep used and end-of-life products out of landfills to prevent pollution and because we are ultimately wasting highly processed and often artificial substances and materials that could potentially be reused again and again.

All substances and materials used in electronics have some degree of value, either because of what they are, like gold, or because of what they can do, like a silicon chip. Nobody is going to try to separate and purify the silicon from the glass, aluminum and other substances in an integrated circuit because the value is in its functionality, not its material content. So its separability as a complete, intact and reusable item is key.

On the other hand, the only material with any value in a used printed circuit board is the copper (and gold or silver, if so plated); the epoxy substrate is a thermoset that cannot be remelted and reused so it is often burned away so the copper can be easily accessed.

If you want to define in-house approaches and metrics for our products’ environmental/health safety and performance you fortunately don’t have to start from ground zero: standards exist that have some good starting places for metrics for separability and other aspects of environmental and human health safety and performance. For example, the IEEE 1680.x series (which I mentioned in a previous column), addresses separability at a fairly high level. Clause in IEEE-1680.1a-2020 requires that discrete plastic parts over 25 grams “Do not contain a metal insert or fastener that is (1) molded in, (2) heat or ultrasonically inserted, or (3) glued in, unless the metal component is either separable by breaking off from the plastic part, or is separable with commonly available tools”. Those over 100g may not “have an adhesive, coating, paint, or finish that is not compatible with recycling.”

It’s all about recyclability and identifying which parts (generally larger ones) recyclers and governments are most interested in making money from and keeping out of landfills, respectively. Separability of batteries, on the other hand, merely requirs that the battery is replaceable, and not necessarily by the user (in clause in 1680.1-2018). Battery recyclability is yet another huge challenge.

Having been involved in the development of some of the IEEE-1680.x standards (.2 and .3, in particular) I can tell you that a lot of multi-stakeholder discussion, argument, negotiation and compromise went into development of its criteria. This makes them a great place to start, even if your product is not directly covered by any of the standards.

So in-house design metrics and checklists that intend to drive products towards improved circularity and environmental/human health safety and performance have a place to start, but those standards are not the end. We will discuss these and other relevant standards and approaches to building your own checklists next month.

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