Using and re-using plastic bottles for storage, especially water, is quite normal in Indian households. A 2-litre Pepsi or Coke bottle is used for months at a stretch as a water bottle, till it finally starts to weather away and we decide to go for a new one. But are you aware of how long you can actually use these? Not just soft drink bottles but even mineral water bottles? How many times do you actually crush bottles after use, as instructed? And the bottles you get in the market, what is the safe duration to use those for storage? Ever given this a second thought? If not, now is the time to wake up because you may be harming yourself.

There is a simple way of knowing how long you can use or re-use a plastic bottle for. How you ask? Well through these numbers in triangles at the bottom.

Mostly, these numbers that are printed inside a triangle, which is the universal symbol of recycling and is called a Resin Identification Code (RIC).

Originally introduced by the Society of the Plastics Industry, the third largest manufacturing sector in the United States, the RIC is now being administered officially by ASTM International, an international standards organization.

The numbers on the code range from 1 to 7 for different kinds of plastic.

Understanding the limitations and usage of each kind of plastic can help you stray away from the unhealthy and harmful ones that could cause serious damage in the long run.

Number 1 represents PET or polyethylene terephthalate.

Which is the most common kind of plastic that you would encounter with the average beverage bottles. Juices, soft drinks, bottled water and such. PET is porous and has a tendency to collect bacteria and residual substances, which means that prolonged reuse of this plastic could be harmful. It is generally considered safe otherwise and can be recycled.

Number 2 represents HDPE or high density polyethylene.

Usually the thicker and opaque kind of containers, the number 2 plastic is most commonly used in milk jugs, to store detergents, butter containers and certain other beverages. This kind is considered very safe and can be reused for storage since it has a low risk of leaching. It is also commonly picked for recycling.

Number 3 represents PVC or polyvinyl chloride.

Most of us are fairly familiar with PVC pipes and tubes used for plumbing and other such purposes. While PVC is tough and rugged, it is considered highly dangerous to cook food items around or store them in. Phthalates used to produce this plastic could stunt hormonal development and cause other more serious problems. Never cook food in these wraps or microwave in them, even if it has been deemed safe to

Number 4 represents LDPE or low density polyethylene.

This kind of plastic is most commonly used for producing grocery bags, some food wraps and bread bags. While this kind of plastic is considered widely safe for the regular storage use, it is not usually accepted for recycling

Number 5 represents PP or polypropylene.

Usually used to produce containers that generally have a cloudy finish and wide mouth, like yoghurt cups, certain water bottles, ketchup bottles and medicine containers. Polypropylene is very safe for storage uses and is also widely accepted for recycling.

Number 6 represents PS or polystyrene, or Styrofoam.

Most common with disposable plastic cups, plates and utensils, the number 6 kind of plastic has recently been speculated to be highly dangerous as it leaches potentially toxic chemicals – especially when heated. Stay away from using these at all if possible. This plastic is also very difficult to recycle.

Number 7 basically represents plastic that are of all other kinds that have not been listed above.

This group mostly includes a wide variety of plastics that were invented after 1987. It could contain anything from Polycarbonates to Bisphenol A (considered very dangerous). Use of this category of plastics is completely at your own risk. So, to be on the safe side, we suggest not using this plastic for any kind of food storage or consumption.

Now, you know your plastics better than anyone. Stay safe.