Waste Material Identification and Segregation
This domain tests whether you can look at a piece of waste and decide three things: what material it is, whether it is safe to use, and which crate or bin it belongs to.
Material groups you must name
- Paper and board: newspaper, cartons, tissue rolls, egg trays.
- Plastics by resin code: PET (1) bottles, HDPE (2) cans, PVC (3) pipe, LDPE (4) bags, PP (5) caps and rope, PS (6) cups. PVC and PS release harmful fumes when heated or burnt - never heat-form them.
- Textiles: cotton, jute, denim, synthetics.
- Metal: ferrous (tin cans, iron wire) and non-ferrous (aluminium cans, copper wire, brass).
- Glass, rubber, natural fibres (coconut shell, bamboo, palm, seeds), e-waste.
Selection rules
Reject anything oily, chemically contaminated, sharp, rusted through the wall, medical or pesticide packaging, aerosol cans, or any battery. Accept material that is cleanable, strong enough for the intended load, workable with the tools you have, and non-toxic once finished.
Segregation at source
Indian rules separate wet (green), dry (blue) and hazardous (red) waste. Inside the workshop go further: label crates by material, rinse and dry everything before storing, flatten bottles and cartons to save space, and keep caps and rings in a small-parts box.
Worked example
A PET bottle is held up. The body is PET (1) - wash, de-label, dry, use as a lampshade. The cap is PP (5) - keep for mosaic work. The tamper ring is a different grade - discard. Reasoning: mixing grades weakens any glued joint, and leftover label adhesive ruins paint adhesion.
Traps
Assuming every plastic glues easily - PE and PP have low surface energy and need keying or hot glue. Storing wet waste beside paper, which causes mould. Keeping a pretty container that once held thinner or pesticide.