Most of Heatbath/Park Metallurgical's rubber cure products are nitrate/nitrite salts. We also offer a nitrite-free alternative for those who are concerned with the possible formation of nitrosamines. With Heatbath/Park Metallurgical rubber cure salts, no reaction with surfaces of extruded or molded rubber parts will occur below 500 degrees F in the normal cure times. All rubber cure salts are completely water soluble and are easily washed. All products are available in free flowing form, a crystalline form with anti-cake agent or in a briquette form under the trade name PARKETTES.