Trump administration delays bans of toxic solvents

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.

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.

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.

Thanks for all the comments and an interesting discussion. Note that the proposal would not outright ban these substances, just particular uses of them.