Ask A Scientist Chemistry Archive

Question:
I asked this in the Chemistry section, but let's give an Environmentalist
a shot. There's an open can of moth ball flakes in the washroom where I
work, being used as a deodorizer. It's main ingredient is a benzene
compound. How dangerous is it to use the washroom and breathe in the air?
There's a sink and toilet in there, a very small space. Should I dump the
stuff?
 gary a latman

Answer 1:
Gary,
 
I gave a short answer in the chem section.
In the past moth crystals were composed of napthalene.
Today I beleive the compound is paradichlorobenzene.
I dont have a toxicity book handy, our technical library is
unavailable. Perhaps someone else has a book handy?
 
Gary, you want to be sure that the material actually is moth
flakes.  There are other air freshening compounds which might
exist in a form similar to moth flakes.  You can ask the janitor
of your building if he has the container from which the material
originated.  There is often handling instructions on containers
of such substances.  In the meantime, I will try to pin down
information for both napthalene and paradichlorobenzene.
 
Ric
Thanks for using NEWTON!

Answer 2:
Benzene is nasty stuff to breathe.  I'm not sure dumping it in the
toilet is the best thing to do with it.  Dropping it in the trash
is probably more appropriate.  Benzene is a known carcinogen and
should be avoided.  Your state office of Occupational Health and
Safety could probably give you standards of workplace exposure.
 mortis

Answer 3:
Para-dichlorobenzene is the stuff you smell in the washroom.
According to The Merck Index:  non-corrosive, non-staining.
Used as an insecticidal fumigant.  Vapors may cause irritation
to skin, throat and eyes.  Prolonged exposure to high concentrations
may show weakness, dizziness, loss of weight; liver injury may develop.
It has an ORAL LD50 of 500mg/kg in rats, which means it took 500mg of
the stuff per kilogram of rat weight taken orally to kill 50% of the
test rats. (For comparison, strychnine has an LD50 of 0.96mg/kg!).
And the anti-cancer drug cis-platin has an LD50 of 9.7mg/kg.  So I
wouldn't be too worried about the bug repellant in the bathroom, just
as long as you don't mistake it for a giant Sweet-Tart! :)
The body's tolerance for chemicals is pretty high, and p-dichlorobenzene
vapors won't do much, especially in the time you spend in the bathroom.
More than you probably wanted to know.
-jschultz