ethidium bromide disposal

Paul N Hengen pnh at
Wed Jun 22 18:25:37 EST 1994

 In article <009803A7.31F85600.4 at>
 vaidyaa at HAL.HAHNEMANN.EDU writes:

> Paul:
> What is the feeling of the community regarding the actual risk involved in
> disposing EtBr?  Are we being too paranoid?  Why doesn't Merck Index include
> more warnings?  Isn't dilution through "dumping" in the sink with a lot of
> flushing a better way to dispose of EtBr?  Perhaps you could write an addendum
> to your TIBS summary.

There seem to be two groups of thought within the "scientific community" on the
matter, i.) those that feel it is okay to dump it down the drain because there
is no "proof" of risk, and ii.) those that feel it's not worth the risk of
finding out it is bad for us or the environment since it "may" be harmful to
humans.  (which is what I wrote in my article).

As for the "layman community", I can't really draw any conclusions, and I think
that kind of question really shouldn't be asked of people not familiar with the
whole issue. I think they look at us scientists for the answers, not the other
way around. Anything that invokes fear in people will cause the scales to asking if we should dump potentially toxic substances.  Of course
people will say no.

Personally, I used to try to decontaminate my EtBr with bleach because I was
told it was okay. Then, after all the talk on the net about it not being any
better, I started tipping the EtBr down the drain. I still had reservations
though, and looked into using activated charcoal...mostly because I don't like
passing anything of strange color through the pipes.  I know it's an odd thing,
but putting stuff like coomassie blue and ethidium bromide into the waste water
gives me the creeps. I think it was an earlier experience that caused this...
While I was an undergraduate at the University of Maryland, I saw one of those
clear pipes in the Skinner Building leaking some dark blue substance down the
wall. This totally grossed me out! Ahhhh...the good ol' days ;-) The
Microbiology Department has since moved out of there and left that blue stain
behind for someone else to look at - one way to get rid of it :-o  Whether or
not it's necessary, I'm now using the charcoal method for peace of mind.
Besides, it's cheap. Better safe than sorry.

> (BTW, your summary of this BBS is a great service.  Thanks!)
> Akhil Vaidya, Ph.D.
> Professor
> Microbiology and Immunology

You're welcome. I love getting all those cards and letters from my fans.
Keep 'em coming :-)


* Paul N. Hengen, Ph.D.                           /--------------------------/*
* National Cancer Institute                       |Internet: pnh at |*
* Laboratory of Mathematical Biology              |   Phone: (301) 846-5581  |*
* Frederick Cancer Research and Development Center|     FAX: (301) 846-5598  |*
* Frederick, Maryland 21702-1201 USA              /--------------------------/*

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