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Trump administration delays bans of toxic solvents

Regulation of high-risk uses of trichloroethylene, methylene chloride, NMP on hold

by Cheryl Hogue
December 20, 2017

The Trump administration is delaying the Environmental Protection Agency’s plans to ban high-risk uses of three hazardous solvents.

Those plans took shape in the waning days of the Obama administration. That’s when EPA proposed the ban on methylene chloride and N-methylpyrrolidine (NMP) in paint strippers and trichloroethylene (TCE) in aerosol spray degreasers, spot-cleaning agents in dry cleaning, and vapor degreasing. These uses put people at risk for cancer and neurodevelopmental effects, the agency determined.

If finalized, the restrictions would mark the first time EPA has prohibited uses of a commercial chemical in more than a quarter-century. In addition, they would be the first such regulations since Congress amended the Toxic Substances Control Act (TSCA) in 2016 to boost EPA’s authority to control high-risk uses of chemicals.

However, the Trump administration on Dec. 14 quietly said it will indefinitely postpone finalizing the planned ban of TCE uses and, at some unspecified time in the future, recast the proposed regulations for methylene chloride and NMP. Such changes could include withdrawing the proposals on methylene chloride and NMP, leaving the two chemicals unregulated.

“EPA is once again kowtowing to the chemical industry,” which has pushed back against the agency’s health conclusions for the three solvents and wants EPA to reassess the compounds, says Richard Denison, lead senior scientist at Environmental Defense Fund, an activist group. He calls the Trump administration’s move an attempt to undermine Congress’s bipartisan reforms to TSCA, which authorize the agency to regulate high-risk uses of chemicals.

Postponement of EPA’s plans for the three solvents is part of a document issued semiannually by the White House that lays out an administration’s agenda for creating or withdrawing regulations.

“EPA’s plan balances its statutory requirements to issue regulations and its commitment to providing regulatory certainty through improvements to existing regulations that were flawed, outdated, ineffective, or unnecessarily burdensome,” EPA Administrator Scott Pruitt says in a statement about the agenda.



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Richard Cornell (December 27, 2017 2:26 PM)
Someone in the White House needs to be exposed to methylene chloride vapors. Once would do. Maybe twice would be even better. The person would call for an EMT as his lungs fill the vapors. His head would spin and vomit gusher out of him. Then the person needs to find the MSDA sheet on all that will happen to a person expose to this chemical.
Scott Hofmann (December 27, 2017 2:59 PM)
I am a chemical products manufacturer and fought against regulation of chemicals for some time. The EPA, Montreal Protocol, and CARB has consistently "thrown the baby out with the bathwater" in vague attempts to make the world safer by those who are by no means chemists, but bureaucrats who have to validate their existence. Seriously good, nonflammable, and inexpensive solvents with low toxicity were banned like Trichloroethane and HCFC 141b,HCFC 124, and many other HFC compounds with extremely low ODP all for a zero tolerance. What we had left are the more toxic compounds like Trichloroethylene and the stupefying Methylene Chloride, which has a poorly inconclusive human toxicity. The end result is extremely expensive alternatives that work inefficiently in comparison to their safer and nonflammable predecessors. For those of you who keep wondering why the cost of your products keep going up and work less effectively, then blame the bureaucrats in charge and not the chemists who are capable of knowing better. Don't get me wrong, I am an environmentalist, too, but as a graduate chemist, I was also taught to be a critical thinker and I think we should go back and reevaluate the good chemicals that we have banned!
Michael Olah (December 28, 2017 11:27 AM)
"vague attempts to make the world safer", what a self-serving viewpoint! The chemistry discipline as a whole has been complicit with far too many horrors in the past. "We couldn't have known" is no longer a valid excuse for us. We can reasonably predict the dangers of chlorinated and fluorinated compounds now, and as scientists we should endeavor to adopt the medical profession's creed of "first do no harm". Paint strippers are not so essential that we must accept solvents with "inconclusive human toxicity" or "low" ozone-depletion potential. The burden of proof should be on us chemists to prove beyond any reasonable doubt that the risks of these chemicals are far out weighed by the risks of not using them. No one get cancer for the convenience of dry cleaning. The environment shouldn't be harmed just because it is easier or cheaper to have a degreaser in aerosol form. If we as chemists can't come up with better alternatives, then either these goals aren't worthwhile or we are not very good chemists.
Brison Shira (January 2, 2018 2:35 PM)
I would seek to find some sort of moderation between Mr. Hofmann's point of view and Mr. Olah's. Mr. Olah is absolutely correct in that chemistry as a discipline must exercise more caution with the assessments we hand down to the general public. On the other hand, Mr. Hofmann brings valuable points regarding the efficacy and other considerations regarding the use of various solvents.

I suppose my insight is really that I am uncertain as to whether or not these substances should be banned or more tightly regulated by EPA. But, I know that the general public should certainly use chemicals of uncertain/disputed toxicity with more caution, following common sense and using their best judgement to limit exposure to potentially toxic substances.

With regards to the environmental concerns, Mr. Hofmann is right that we should have substantial rationals before eliminating chemicals from use. Overall, these chemicals are relatively minor in the grand scheme of environmental issues. Surely more utility would be garnered by investing our time and effort into clean energy and other more rewarding ventures than quibbling over relatively insignificant damages to the environment.
Bill (December 28, 2017 2:15 AM)
Wow, what a d1ck. It's not like anyone at the white house mandated huffing these chemicals. Everyone is still free to use them in a responsible manner, with proper safety gear.
David Mendenhall (December 29, 2017 12:08 AM)
I am frequently exposed to methylene chloride vapors in the lab I own. I have never called the EMT because my lungs filled with vapors. It is an excellent low-boiling solvent with minimal toxicity. If you sniff it like teenagers in my generation sniffed glue you will probably have health problems like you describe. This comment is typical Type 1 safety stupidity: when the "safety" person invents or grossly exaggerates the dangers.
Karel Vlok (December 27, 2017 2:59 PM)
I don't know, I spent many years with these three solvents, mainly manufacturing blends for an electrical cleaning application. Forty years later I still think that they takes some beating.

Of course one needs to be aware that volatile solvents with high Kauri- butanol values will do harm if not properly used. One cannot expect a methylene chloride based paint stripper to only strip part of the paint.
Mark W Maxwell (December 27, 2017 4:33 PM)
In 1971 I was working in a construction testing laboratory that used TCE to extract asphaltic cement from core samples of roads and parking lots. Samples were placed into a cetrifugal extractor to separate the aggregate from the asphalt and the aggregate was then dried for sieve analysis in a pie pan over an open flame burner of a household stove or in the stove's oven. The place reeked of TCE and combustion products for hours. One of the people did numeroius samples from early in the morning to after 6:00PM. After finishing for the day, he went to a nearby pub for food and a few beers. He never made it home that night, but had a couple weeks stay in hospital. He later said that when they took blood samples, his blood looked like hot chocolate coming out of his arm!!! A few days later I happened across a medical review article that sounded exactly like what happened to him. A mason was putting ceramic tile in a very large room with no ventilation and then degreased sections with TCE while waiting for the newer grout to set. He also went out to eat and have a few beers. All of the symptoms, including the chocolate blood, renal shut-down, and a near comatose state, were the same as my co-worker. The next day I showed the article to the laboratory owner and he immediately stopped all TCE use until he could have heavy-duty blowers and hoods built over the extracor and above the stove. This was all before MSDSs and PPEs. All I can say is know you chemical, read the MSDS, use your PPEs, and thankfully I was in a group doing soil compaction tests.
Art S (December 28, 2017 10:03 PM)
Observing what it does to those closest to the exposure fails to examine the cumulative effect on mankind and the environment. We are still not sure what is causing the sperm count to drop in the US male population. Or the effect of PCBs in whale blubber. But what is clear is that 6 billion people can really make a mess of the planet Everyone needs to examine hazards and risks in much broader manner otherwise more harm, like asbestos, but in a perhaps a more subtle way, will be the result.
Peter J. Daudey (December 29, 2017 10:55 AM)
To my opinion, all C1 chemicals and C1 moieties are unsafe for humans. Methanol (solvent for glues, present in sigarette smoke) is oxidized by Alcohol Dehydrogenases in the human body to formaldehyde. The direct action of formaldehyde is to react with proteins and crosslink them. This is a major cause of lung cirrhosis (COPD) and liver cirrhosis. Formaldehyde is a well known genotoxic since it is able to randomly methylate DNA. In addition, methylation triggers the human immune system, leading to auto-immune responses. An acute response of methanol poisoning is damage to the eye's nerves and retina causing the well-known methanol blindness. This damage is caused by methylation followed by cleanup of the methylated myelin by the immune system.

Methylenechloride is first hydrolysed to methanol, hence links in to the same mechanism. Methylene di-chloride directly hydrolyzes to formaldehyde.

In toxicology literature there is a lot of noise on the toxicity of methanol, where the reference to formaldehyde seems to be avoided, possibly to defend the widespread use of methanol. Instead, in many cases formic acid is named as the poisonous substance formed from methanol. Yes, in the end all formyl moieties and intermediates will end up as formiates/formic acid, but the damage is done by the reactive formaldehyde intermediate. My conclusion is that all lone carbons in any manmade covalent compound should be considered suspect, since they all may end up in methanol, formaldehyde. Most potent drugs contain these moieties, e.g. N-methyl groups or formyl groups. Apparently, in Pharmaceutical development, the potency of formaldehyde is well known. Many of these drugs are known carcinogens, most probably for this reason.

To a lesser extent, chlorinated C2 compounds will end up in toxic chemicals, like ethyleneglycol that is well known to cause renal damage, as indicated in the comment of Mark Maxwell. Ethyleneglycol is oxidised enzymatically to oxalic acid that precipitates with calcium ions.

Since producers of chemicals have no short-term commercial reason to investigate toxicology, a clear role of an independent "judge" like the EPA is needed.
Russ W (January 1, 2018 12:58 PM)
Some of the commenters appear to be unfamiliar with one of the most basic findings of toxicology. If you expose 1,000 individuals of the same species to the same dose of a substance, some individuals will exhibit observable effects and others won't. Why? Because of differences in age, sex, health status, prior exposures, co-exposures, and genetics. Thus, the apparent lack of effect on one person is not any kind of proof that the exposure was safe. Human nature hates this result - - if we experience an exposure and ask "is this exposure going to hurt me?" we want "yes" or "no" for an answer. But the only answer that can be given is "maybe". So where does that leave us? We need to balance the benefit of the substance against the risks against the uncertainty. (That last factor tends to be overlooked.) Do we have the ability to do that as individuals? Very few of us do. (See Peter Dauday's comment - that's the kind of insight I'm talking about.) That's where science and government come into play. We need a hell of a lot more research and then we have to recognize that somebody is going to make "the call" about the acceptability of a substance's use. (And, according to the post-1970 acts of Congress, that would be EPA, FDA, etc.) Industry shirks research expenditures for obvious reasons. Government agencies never get the funding they need. Leaves us in a tough spot...
Cheryl Hogue (February 7, 2018 10:09 AM)
Thanks for all the comments and an interesting discussion. Note that the proposal would not outright ban these substances, just particular uses of them.

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