[Drew68]

I see no evidence of there ever being a PETA lawsuit against the EPA.

I was mistaken. It doesn't appear there was a formal lawsuit, just a publicity campaign. In Hynde's own words,

"In light of Rush Limbaugh's vocal support of PETA's campaign against the Environmental Protection Agency's foolish plan to test some 3,000 chemicals on animals, I have decided to allow him to keep my song, 'My City Was Gone,' as his signature tune and to donate all proceeds from the deal to further PETA's efforts in that regard" ...

Really Randoms: Chrissie Hynde, Ricky Martin, Jimmy Page Rolling Stone (Aug 28, 1999)

For whatever it's worth.

[nickcarraway]

That’s weird, because I’ve also read several times that she allowed him to use it because her parents listened, and just on general principal.

[rikkir]

That’s cool.
In this instance I would agree with PETA’s position as well.

Testing medication on animals, I got no problem with.
Testing hairspray, by spraying it in some animal’s eyes serves no purpose except cruelty.

I have a solution for both.
Let’s test chemicals on Government Bureaucrats.
They’re much more useless than most animals. :)