Some chemicals are very caustic.
Your supplier or the manufacturer can assist you with that information. A Water 52 degrees centigrade 750 ml Metol 10 grams Sodium Sulfite, anhydrous 50 grams Cold water to make 1 liter. Solution B Water 52 degrees centigrade 750 ml Sodium Carbonate, monohydrated 50 grams Cold water to make 1 liter. Dilute further for contrast reduction. This is similar to Agfa's Rodinal developer.