Methylene Chloride Proposed Ban: Misguided Policy
Am I the only person who thinks the EPA’s proposed ban on methylene chloride
in paint strippers is a big and unnecessary overstep by government? Ever
since the EPA announced on May 10, 2018, that it plans to go ahead with plans
to finalize a ruling doing this, I’ve seen a lot of reporting, but nowhere
have I seen any objection to this ban.
I wrote about this issue in the June 2017 issue of Popular Woodworking
(#232), and I recommend this article to you if you would like to read more
of my objection. In this article, I told how the EPA has been trying to ban
methylene chloride for over three decades. Until recently, the main argument
has been that it causes cancer. The problem with this argument is that all
the evidence indicates otherwise. So it appears that now the argument has
been expanded to include how many deaths the solvent has caused due to acute
Acute exposure is a problem because methylene chloride metabolizes to carbon
monoxide in the bloodstream, replacing oxygen. This can lead to a heart
attack, especially in people with a pre-existing heart condition.
The number of deaths reported is between 40 and 50 since 1975 or 1980
depending on the source. That’s less than 2 a year. Say that again, less
than two a year!
The primary way this seems to happen is with people who strip wood and other
materials in a bathtub in a closed room with no air circulation. The closed
room is a problem, of course, but in addition, the person is probably leaning
into the tub to scrub off the paint or finish. Because methylene chloride is
heavier than air the buildup of fumes inside the tub would exacerbate the
lethality. Also, because the methylene-chloride molecule is so small, most
vapor masks are ineffective at blocking it.
I don’t want to be accused of minimizing anyone’s death, but are two a year
enough to justify removing this extremely effective solvent from the
marketplace? Strippers based on methylene chloride are by far the fastest
acting and strongest we have available, and their substitutes all have
problems. The question about banning any product always comes down to
weighing the benefits against the harmful effects. I don’t think these
harmful effects justify the ban in this case.
And I don’t see any reason why manufacturers couldn’t be required to put
much better warnings on the cans. The stripper could even be kept in locked
cabinets, which require a store clerk to open along with explaining to
customers that air movement into and out of the stripping area is vital.
While researching on the Internet, I came across this CBS morning show
report from last December, which I found not only misleading but also over
the top in hyperbole. The people discussing the issue tried repeatedly to
outdo each other in their horror that methylene chloride was still available
to the public.
Notice about two minutes into the accompanying video that there’s a bathtub
example showing the fumes rising out of the tub, demonstrating a complete
lack of understanding of the solvent. It’s heavier than air, so it sinks and
accumulates, especially in the confines of a bathtub.