Some buffers are toxic and should be handled with the same care as fixatives.
Di-Sodium Hydrogen Orthophosphate is used in conjunction with trisodium phosphate in foods and water softening treatment. In foods, it is used to adjust pH. Its presence prevents coagulation in the preparation of condensed milk. Similarly, it is used as an anti-caking additive in powdered products.
Some buffers are toxic and should be handled with the same care as fixatives.
Please see the relevant MSDS here