Since when are coal-burning power plants “consumers”? A look at NSF’s dubious recycling definitions.

Fly ash, a by-product of coal combustion, is considered “post-industrial” or “pre-consumer” recycled content by just about everyone…with the notable exception of NSF, which recently, and inexplicably, decided to label fly ash “post-consumer” for its NSF-140 carpet standard.

NSF justifies this labeling change—explored here by the Healthy Building Network’s Tom Lent—as follows:

“It is our contention that coal is consumed by the utility (the end consumer of the coal) in the process of production of electricity and that Celceram [Boral’s branded fly ash] is a product that can no longer be used for its intended purpose (i.e., the generation of heat to create steam) and would otherwise be sent to the waste stream.”

Hmm, industrial waste is now post-consumer recycled content? It is a dubious argument at best.

GreenSpec’s fly ash policy

For now, GreenSpec supports the use of fly ash in building products such as concrete because it improves concrete’s performance and replaces a significant amount of portland cement, which is energy-intensive to produce and generates carbon dioxide and other hazardous emissions during calcination.

As before this “post-consumer” flap, GreenSpec does not support the use of fly ash as a filler in products such as carpet backing where its use does not significantly reduce greenhouse gas emissions.

Toxicity concerns

The main reason for this was brought up Tom Lent: fly ash contains trace amounts of mercury and a number of other toxicants. These can be released into the watershed when landfilled, but when fly ash is used in concrete, the minerals become part of the chemical reaction and the toxicants “bound,” minimizing the risk of exposure or leaching, but that’s not the case when it’s used in carpet backing.

Even the data about leaching from concrete are not conclusive, however, and we are keeping an eye on the research. Some people think fly ash should not be used in green buildings, but it is important to remember that portland cement also contains hexavalent chromium and trace amounts of hazardous compounds, so eliminating fly ash from concrete will not entirely eliminate toxicity or potential end-of-life disposal concerns.

NSF is tarnishing its certification

Fly ash is a complicated issue, and we don’t need to add to the confusion, but NSF might be doing just that by erroneously boosting the number of LEED credits available for recycled content and watering down the NSF-140 Platinum standard.

Carpets that now meet its “gold” standard could be transmuted into “platinum,” encouraging other carpet manufacturers to include fly ash in their products. And if you want to avoid fly ash in carpet, good luck finding that information among the NSF-140 documentation, as the credit information for individual products is not readily available to the public.

Moving forward

GreenSpec is going to stay consistent with its longstanding policy and will not follow NSF’s decision to label fly ash in carpet as “post-consumer” recycled content.

And we join HBN in calling for LEED to do the same. From now on, GreenSpec will scrutinize NSF-140 Platinum carpets and will continue to reject any that contain fly ash.