Lesson 3. Blue and green: what ruins a batch

At a paper mill, wastepaper is loaded into a pulper: it's mixed with water, and the fibers break apart into a slurry. Then staples, plastic, and ink are removed, and a new sheet of paper is made. GREASE BREAKS THIS PROCESS PHYSICALLY. It's water-repellent (hydrophobic): it doesn't mix with water, floats up as a film, and, above all, doesn't separate from the fiber it has soaked into. The whole batch can be ruined. So: — a greasy pizza box goes in brown (and where there's no organics container, in resto); — used napkins and paper towels go in brown; — the clean lid of the same pizza box can be torn off and put in blue. THE SECOND ENEMY IS CHEMICAL COATING. — Receipts are printed on thermal paper: it has a reactive coating and is incompatible with paper recycling, so resto. Better still, ask for a digital receipt. — Paper coffee cups are lined with polyethylene inside — resto. — Meat and fish wrapping from the counter, laminated paper — resto.

A glass furnace runs at 1,500–1,600 °C. Ceramics, porcelain, and Pyrex don't melt at that heat: they stay in the molten glass as solid inclusions (infundibles). Each inclusion is a stress point in a new bottle's wall: it comes out defective and breaks on the line. One plate can ruin a batch. Crystal harms differently: its lead oxide alters the batch mix. NOT IN THE IGLOO — AND WHERE INSTEAD: — Drinking glasses and wine glasses — resto — Ceramics, porcelain, plates, cups — resto — A small mirror, glass shards — resto — Window glass, large mirrors, Pyrex — punto limpio — Incandescent bulbs — resto — Energy-saving and LED bulbs — punto limpio (electronics) — Medicine bottles — the pharmacy, Punto SIGRE A broken drinking glass needn't go to the punto limpio: small shards and dishes go in resto. WHAT DOES GO IN: only botellas, tarros, frascos — bottles, jars, perfume and cosmetic bottles, empty. Leave the label; the metal lid goes in yellow. MADRID CITY HALL'S OFFICIAL MNEMONIC: Si lleva tapa, tapita o tapón, es vidrio. If it has a lid, a little lid, or a cap, it's packaging, and it goes in the green one. A bottle, a jar, a perfume bottle have one; a drinking glass, a plate, a mirror don't. That covers almost every household case. It works: about 2% contamination in green versus 33.4% in yellow, and glass recycles endlessly without losing quality.