As a food jar, it will often contain mayonnaise, premixed salad dressings, honey and spreads like peanut butter. You will also find PET plastic in microwavable food trays, biscuit trays, salad domes and some shampoo and conditioner bottles. Many people reuse PET containers, especially water bottles and there is quite a deal of debate about chemical leaching when PET 1 plastic is reused, especially when subjected to heat and light. It is best to not reheat any kind of plastic if you intend to consume it's contents. Heat tends to promote chemical leaching from the plastic into your water. And remember that heat comes from many sources. Don’t leave your plastic water bottle in sunny places like in your car.
There is also considerable information around in relation to PET water bottles dropping microplastics into consumables inside. Most microplastics in bottled water come from the container lid or the water itself. PET plastic is generally recyclable and it goes into your council recycle bin. Please ensure that the container is empty and rinsed before you dispose of it in your recycle bin.