Both The Pump Handle and OSHA Underground had short posts today on our withdrawal of the ANPR (Advanced Notice of Proposed Rulemaking) for diacetyl. Neither really came out and said if this was a good thing or a bad thing, but I think it's a good thing.
First, NIOSH has been unable to state with absolutely conviction that bronchiolitis obliterans (popcorn lung) is caused by diacetyl. The evidence is certainly leading us that way, but what if the evidence is misleading? What if it's a different chemical? What if we're dealing with a true synergistic effect and diacetyl acts more like a catalyst and there is no safe level for diacetyl (food flavoring are such complex chemical mixtures that I think this is a very real possibility)? Remember that OSHA does not have the statutory authority to ban the use of any chemical, which means we have to set an exposure limit, but at what level, when we're not even sure what chemical is causing the problem, much less what a safe level is?
Second, from what I've heard (I do not have confirmation of this), the flavoring manufacturers have begun to remove diacetyl from their products. How much sense does it make to promulgate a standard if no one is exposed any more?
The problem we're left with is what do we do now, after all people are still being exposed to the hazard. If the manufactures do remove diacetyl from flavorings then the problem takes care of itself. If FDA gets involved and bans diacetyl from flavoring, the problem takes care of itself.
In the interim we have the National Emphasis Program on flavorings, which is the only solution I see short term. But what happens if neither the industry nor FDA act and remove diacetyl? I guess we're back to rulemaking and hoping that the science better defines the problem. Not very satisfying I know, but what else can we do?