Ethidium bromide

[Dima Klenchin]

Wolfgang Schechinger wrote:
:Deanne, 
:
:> One of my "general rules" is this: if a substance reacts with
:> nucleic acids or proteins - give it some respect.  When in doubt
:> or ignorant of something, be cautious - not careless.
:
:this is very good rule of thumb 
:
:> 
:> If a safety person makes a recommendation, give it some heed. 
:
:<snip>
:
:The problem with safety rules however is,  that their basis is 
:not safety issues in the first instance but that nobody wants to 
:take responsibility. I wouldn't be astouned when suddenly 
:even deionized water gets some orange label.

:Recently, I have disovered a dead head sign (poison) on a 
:bottle with acetic acid (irritant and flammable is what I would 
:expect to be there). The consequence is, that a newbie 
:without a lot of practical experience will loose any sense for 
:the real danger of chemicals. Where's the difference to the 
:really toxic stuff now?

I agree. This overkill is a classic case of boy crying wolf. 
My favorite notes on the subject are sucrose ("explosive")
and ATP ("toxic"). 

:Of couse I would have a sip of conc HOAc or have a bath in it, 
:but I wouldn't doubt that my body easily will detoxify an 
:accidental breath of it (what I would doubt in the case of EtBr).
:
:It seems to me there is a lot of hystery on lab hazards: 
:micrograms of EtBr are detoxified (??) with grams of 
:permanganate first using lots of HCl for acidification and the 
:lots of NaOH for neutralization, potentiating the waste by 
:magnitudes. But you have fulfilled the lab rule / satisfied the 
:safety officer / peace of mind (!?)
:
:One could continue almost endlessly.

In the same vein. The worst part is when the rules become 
too ridiculous and burdensome, many people stop following
them and - again - in the process lose track of what's reasonable
and what's not. 

        - Dima