Subject: Re: Chlorine, carcinogens and dead fish
From: wtmorgan@pilot.msu.edu (Bill Morgan)
Organization: Michigan State University
Date: Thu, 08 Jan 1998 10:49:56 -0500
Message-ID: <MOD$980108.17428@rec.gardens.ecosystems>
References: <MOD$980108.8990@rec.gardens.ecosystems>


In article <MOD$980108.8990@rec.gardens.ecosystems>, hillersb@aol.com
(Hiller SB) wrote:

> I picked up a bottle of fish emulsion the other day and found the following:
>
> Nitrogen 5 percent
> Phosphorus 1 percent
> Potash 1 percent
>
> Chlorine 4 percent
>
> Chlorine is well known to convert organic material into carcinogens.
>
> Since I do not consume anything I fertilize with dead fish (house plants
only),
> I don't worry about it, but the directions do include a dilution (3 T. per
> gallon) for vegetables.
>
> Should anyone be frightened by this?
>
It depends a lot on what form the Chlorine is in. It could be Chlorine per
se (dissolved as a gas in the water) but could also be in some ionic form
(e.g., chloride or hypochlorate)

The form matters a lot. We take in chlorine all the time as the chloride
ion in salt without any harm, but elemental chloride is pretty tough on us.

Not knowing what the form is makes it tough to discuss toxicity,
carcinogenic potential or anything else. Assuming that it is the dissolved
gas, yes, that is highly reactive and can chlorinate some hydrocarbons.

But, if you are using city water, it is probably chlorinated and you are
likely adding more chlorine to your garden by watering than you'd ever get
from the fish emulsion.

If you want to get rid of the chlorine in the emulsion (again, assuming it
was added as chlorine gas), warm the stuff up: gasses lose solubility in
water as it heats up. Or just let it "air out" the same as people do with
chlorinated water before using it in aquariums. You'll never get rid of it
all of course, but you can get rid of most of it.

Regards,
Bill

--
Bill Morgan
wtmorgan@pilot.msu.edu
Center for Room Temperature Confusion