There are seven categories of plastic bottles, PETE(1), HDPE(2), PVC(3),LDPE(4), PP(5), PS(6), This classification is based on its usage and impact.
PETE (1): This is known as Polyethylene Terephtalate . This type of plastic bottle looks thin and clear and has #1 at the bottom. Studies have found that PETE (1) plastic is safe for one time usage, best suitable for disposable water bottles. As a safety measure, these bottles should not be heated, it contains porous surface which allows flavour of the drink and bacteria to get accumulated, so it is best advised not to reuse these types of bottles.
HDPE (2): HDPE is known as High Density Polyethylene. This type of plastic looks thick and opaque. The bottles made up of using this plastic will have #2 at the bottom. These types of bottles are safe when they are reused one time, juice bottles, shampoo and milk jugs use these types of plastic bottles.
PVC (3): PVC is known as Polyvinyl Chloride. This type of plastic looks rigid or flexible, PVC bottles has #3 at the bottom. Food wraps, cooking oil uses these types of plastic bottles. This type of plastics is not safe to use as it contains phthalates which is used as a softening agent. This type of plastic should not be recycled; continuous usage may affect the hormone development in human.
LDPE(4): LDPE is known as Low Density Polyethylene. It looks soft and flexible, mainly used in making bread bags, grocery bags, and food wraps. This type of plastic is considered to be safe for usage.
PP(5): PP is known as Polypropylene. It looks hard but flexible. Yogurt containers, drinking straw, syrup bottles are made using this type of plastics. These plastics are very safe and can be recycled when needed.
PS(6): PS is known as Polystyrene Styrofoam. It looks rigid and solid. Disposable cups and plates are made using this type of plastics. It’s been found that this type of plastic gives potentially toxic chemicals when it is heated, so it is advisable not to use this type of plastics.
Others(7): This means rest of all plastics which includes Polycarbonate, a harmful Synthetic Estrogen made from BPA. Plastic items such as computer case, five gallon water bottles are made using this type of plastics. The usage of this type of plastics is at our own risk since no one knows the side effect yet. Things made of BPA plastic need to be disposed since it is very harmful.
The Plastics #2, #4 and #5 are considered to be safe. But we need to be careful while using them particularly when heating it and using in microwaves. It is better to avoid using plastics and use glass bottles or any silver container especially for kids. It is the responsibility of the Parents to choose right containers to ensure the safety of their children.