The vinegar used in household cleaning is table vinegar and has acetic acid in 5-8% concentartion making it considerably safe. Here are some useful "cleaning with vinegar" tips - *Pour vinegar into the toilet bowl and let it sit for about 30 mins.Later, sprinke some baking soda and scour and brush any stains. You will have a sparking toilet. *A vinegar rinse can leave your crystal dishes, mirrors, windows with a shine. *Vinegar works wonders if there is cigarette smell in your car or home. *Mix about 1 tbsp of vinegar in a bowl of water and let it boil in your microwave. This removes food odour and also loosens the grease stains and food particles. After this boil, just wipe clean your microwave with a soft wet cloth. *Once a year, dump 2-3 litres of vinegar in your hot tub and let it run for a few minutes. This will keep the jets from clogging with soap residue. *For stubborn stains on carpets and rugs, rub with a solution of vinegar and water in 2:1 proportion. *Spraying vinegar around your litter box or pet's crate will remove any odour. This is better than using an air freshner. However, do bear in mind a few things while handling vinegar - *Keep out of reach of children. *Do not inhale the fumes of vinegar. *Never mix vinegar and bleach. I hope you find these tips useful as almost all of us have vinegar in our kitchen shelf always.