>>27012779The only steel types which would be bothered by toxic more than its secondary fire typing are Heatran, Empoleon and the Steel/Rocks since they don't have an issue with switching into a potential fire attack since Flash Fire in Heatrans case and neutral damage on the latters.
Something like Skarmory should be more worried about a Flamethrower just hitting it for super effective and doing a high amount of damage on its weaker defensive side than getting slapped by a toxic, though the toxic threat does add to it staying out of 1v1ing it and assuming it gets a good amount of special attack anyway.