If you find triangle with number 1, the bottle is known as PET or PETE. It can be used only once and shouldn’t be reused because it can emit antimony, a heavy metal which can interfere with hormones in the body and can be even be carcinogenic.
If there is a triangle with the number 2, this type of bottle is known to be HDPE or HDP. This type of bottle is made up of great plastic and doesn’t have as much chemicals that are in other bottles.
V or PVC has the number three inside the triangle. There are two known toxic chemicals that are found in these bottles that influence the hormones in the body. PVC is very common plastic for many things other than bottles.
The bottle is known as LDPE. This is also good plastic and most often used in water bottles and plastic bags. They don’t emit chemicals when used in water bottles.
On the bottom of a container there is a mark with the number 5 that is transparent to the container stating that it’s safe you will usually find these on yogurts or even syrup. This type of plastic is called PP.
When you see the number 6 on plastic, which you can find on fast food packaging and coffee cup is has been proven to be carcinogenic because it contains STIREN.
When you see the number 7 it is known as PC plastic. You should avoid using these bottles because the plastic emits BPA, a very harmful chemical. Unfortunately, PC plastics are commonly used in containers for food, sports drink bottles and infant bottles.