ALERT: "Lactic-Acid" OK-P should not be used. Serious chometz issue.
OU among others etc. does not allow it in their products.
OK Poiskim agree that it's a chometz issue. They were over by the OK senior staff.
Any Pesach product with a Heimish Hashgocha, if it has OU you are safe.
Don't use if it has an OK.
Any pesach product without an OU, check with the certifier if they are using the OK Lactic-Acid.