H&C® Etching Solution removes efflorescence (alkali salts) and can also reduce the pH level of new concrete and new mortar joints. As a phosphoric acid-based solution, it is user-friendly and won't harm plants or vegetation should it come in contact with it. Simply spray any surrounding vegetation with water so the Etching Solution can roll off. This product can also be used indoors (basement floors, interior concrete floors), should the project warrant it.