1/4 cup baking soda 
1/2 cup vinegar 
Directions
1Pour baking soda into drain. 
2Follow with vinegar. 
----------
Sodium Hypochlorite = bleach NaClO,
Sodium Hydroxide = lye NaOH , 
Hydrogen Peroxide = H2O2 (weak acid), 
Biodegradable Surfactant, 
Hydrotrope, 
Sodium Silicate (corrosion inhibitor). 
Contains no Phosphorus