So, i been wondering how to get the suit or item? I looked on the general web and didn't get any answers. There (Used) To be quest and missions where you could get them. But i don't see they exist in the game anymore.
If you're looking for the item to protect you from radioactive planets, you're gonna need this :http://starbounder.org/Radiation_EPP_Upgrade
And if you meant the Hazmat Suit vanity set, it can be found in alien biomes, toxic biomes, jungle biomes, and swamp biomes.