Plastic has become a part of our day to day life. Just by taking a look around our home we can tell that it is practically impossible to totally cut off plastic from our life. It is used as food storage containers, shower curtains, toys, water bottles, pipes, medical bottles, cosmetic pallets, cutlery and many more. Plastic surrounds us from everywhere.
All these plastics are chemicals also with increased use they have found a way to enter our body and environment causing serious biological consequences. Due to this reason, the Society of the Plastics Industry (SPI) devised a classification in 1988. It classifies plastics in different grades called Resin Identification Code, which is a number printed at the bottom of the plastic containers and bottles indicating the plastic resin used in manufacturing that product. This number is printed within the recycle logo, which is a triangle formed by arrows.
GRADE 1 - Polyethylene Terephthalate (PET)
This grade of plastic absorbs odours and flavours from foods and beverages stored in them. Brominated compounds have been found to leach in PET bottles and bromine is associated with disorders of the brain causing psychotic symptoms. This leaching depends upon various factors like sunlight, temperature and pH. Typically this plastic is used to make water bottles, food containers, bottles for squashes, mouthwash, ketchup, jams, rope, clothing and carpets.
GRADE 2 - High Density Polyethylene (HDPE)
It is comparatively a low-hazard plastic and used to make bottles for storing water, milk, shampoos and juices. These are commonly recycled. If originally an HDPE bottle is not used to keep any eatables, then it is never recommended to reuse any HDPE bottle to store any edible food product.
GRADE 3 - Polyvinyl Chloride (PVC)
Plastic made of this grade is sometimes recycled and usually used to manufacture pipes, tiles, bags for bedding, credit cards and blister packs used to store medicines. PVC floorings are linked to the cause of some diseases like allergy, asthma and autism. This type of plastic should not come in contact with any kind of edible product.
GRADE 4 - Low Density Polyethylene (LDPE)
This plastic is again low-hazard, flexible and durable. Commonly used to make sandwich wraps cling film, squeezable bottles and grocery bags. Though it doesn’t contain BPA (Bisphenol A) which is a chemical used to make plastic and resins that are potentially harmful for us, but the risk of leaching cannot be ruled out completely in LDPE plastic.
GRADE 5 - Polypropylene (PP)
Plastics made of this grade are highly heat tolerant and used to make containers for yoghurt, medications, ready-to-eat meals, syrup bottles, Tupperware, caps and straws.
GRADE 6 - Polystyrene (PS)
It is also called as Styrofoam and used to make disposable plates, cups, bottles, bowls, trays and packaging foam. It has been shown to leach styrene in food items and causes cancer and damage to the nervous system. Temperature is the most effective factor which determines the rate of leaching. PS plastic is also recyclable.
GRADE 7 - Other
Plastic falling under this grade is made up of Polycarbonate and Polylactide. These plastics are difficult to recycle and generally used to make baby bottles, CDs, storage containers and number plates. This plastic is not recyclable.
As discussed above that BPA is a type of chemical used in manufacturing plastic items. But always remember that it is not necessary that a BPA - free plastic will be safe to use as there are other chemicals as well which are capable of leaching. Some of the ways through which they can leach in our foods are microwaving food in plastic containers, storing acidic food like ketchup, keeping hot foods in plastic containers, etc. Hence, it is always safe to use glass, bamboo and eco-friendly containers as they are microwave safe, dishwasher safe, also doesn’t cause any leaching and staining.