adulterated milk as face pack?

Friends........most of use face packs at home. And some of these packs need milk or curd as one of the ingredients.
I also do use like that. But mow adays am worried about the purity of milk, since most of sellers of milk make it adulterated.
Because our digestive system can bear with the adulterated milk but its harmful for our skin when applied to it.
Where do we get pure milk....is there any solution to it?

 

assam..............why?

 

ok................no doubt thats true........but i think since that goes through various processes, to make the milk pure........will it be suitable to be used on face?