🔬 Plastic Literacy
Plastic is not found in nature — it is engineered. Almost every plastic item begins as crude oil or natural gas, is cracked into small molecules called monomers, and is then joined into long chains called polymers.
Common Polymers
Each polymer family behaves differently, so the recycling symbol on a product matters more than the word “plastic”.
| Polymer | Monomer | How it is made | Typical uses | Recyclability |
|---|---|---|---|---|
| Polyethylene (PE / HDPE / LDPE) | Ethylene | Steam cracking -> ethylene -> addition polymerisation | Bottles, carrier bags, milk pouches, detergent bottles | High - widely recycled (HDPE) |
| Polypropylene (PP) | Propylene | Steam cracking -> propylene -> addition polymerisation | Caps, food containers, straws, bottle caps, ropes | Moderate - but often confused with PE |
| Polyvinyl Chloride (PVC) | Vinyl chloride | Ethylene + chlorine -> VCM -> addition polymerisation | Pipes, cable insulation, toys, medical tubing | Low - difficult and often downcycled |
| Polystyrene (PS) | Styrene | Steam cracking -> styrene -> addition polymerisation | Foam cups, food trays, packaging, school kits | Low - EPS foam is almost never recycled |
| PET (Polyethylene Terephthalate) | Terephthalic acid + ethylene glycol | Polyesterification + polycondensation | Water/soda bottles, food trays, polyester fibre | High - mechanical + chemical recycling viable |
How Long Does Plastic Last?
Polyethylene (PE / HDPE / LDPE)
~10-20 yrs in landfill, 400+ yrs to fragment
Polypropylene (PP)
~20-30 yrs in landfill
Polyvinyl Chloride (PVC)
~40-50 yrs in landfill
Polystyrene (PS)
~30-50 yrs in landfill
PET (Polyethylene Terephthalate)
~450 yrs to fragment
Six Reasons This Became a Crisis
Persistence
Conventional plastics take roughly 400-1000 years to degrade in nature. They rarely disappear - they only fragment into smaller and smaller pieces.
Microplastics
Sunlight (photodegradation) and friction fragment plastic into particles 5 mm or smaller that wash into soil and water systems.
Soil Contamination
Soil microplastic levels are reported 4-23x higher than in oceans, disrupting microbial communities and nutrient cycling.
Ocean Gyres
The Great Pacific Garbage Patch spans about 1.6 million km2 and holds an estimated 1.8 trillion pieces of plastic.
Open Burning
In many Indian cities plastic is still burned openly, releasing dioxins, furans, and particulate matter directly into the air people breathe.
Single-Use Culture
Around 40% of plastic produced is used once and thrown away within minutes, which is the root cause of the waste stream.