Just saying, that person needs to do their research more before posting reviews like that. One look at the name alone tells you it's chemical make-up. However, in case I was wrong, I thought I'd look. There are a few things wrong with that post anyways:
1.) Any person who is going to throw out information would never say "Wikipedia said this". IMO it should end there, but let's keep going.
2.)Here's a five second chemistry lesson. Ethoxyquin is made up of nothing but variations of carbon and hydrogen bonds with ONE nitrogen latched on (given it is an cyclo-alkene, but that just makes it a little bit more difficult to break down...but not bad). Point is, it is easily broken down by water. And the nitrogen that is left over? That is all part of the natural cycle anyways within the biome in your water.
Here is a link given in more detail on the chemical itself.
I googled the wikipedia study, just to see the original reference. This is what I was led to:
I followed links on the site which led me to another site. This one:
The mortality thing worried me. So, I clicked on the link there which led me here:
Which shows that they have only
tested this on two
types of trout
If I could make an educated guess, I would assumed that these trout tests were done in an attempt to test water contamination reactions. To further support this, they had another test, in which they may have wondered what would happen in smaller doses, where they found that fish do not actually die. (Slightly toxicated). Thus, showing that in smaller and smaller doses, this can be used as a pesticide in fish food. This is simply speculation on reasoning behind the tests in the first place, though.
I am wary of these tests, simply because there have been so few conducted.
What I mean by posting all of this is that this company isn't going: "hey, I know this is lethal for fish, but let's do it anyways." This is a preservative that has, according to Wikipedia, been tested. However, I do not always trust Wikipedia, because some of the information on there is iffy (for lack of better words). I think that Omega One Betta Pellets are fine. I think that the person is simply over reacting and putting a huge scare into people that isn't needed. Honestly, it's things like that, that drive me crazy. I hope that the info provided can help put your mind at ease.
Omega One Betta Pellets and New Life Spectrum are pellet types that are often suggested on this forum.
Please keep in mind that pesticides are often the center of debate, especially for the "they put something in our water!" enthusiasts.