It's easy to assume that broken glass and old ceramics belong in your kerbside recycling, but most of them don't — and getting it wrong can injure collection workers or contaminate an entire load. Glass that shatters into small shards can't be sorted by machinery, and ceramics behave very differently from glass bottles when melted down. Knowing the difference, and handling these materials safely, protects both the people who process your waste and the quality of what actually gets recycled.

Let's start with what the yellow bin will and won't take. Across most New Zealand councils, the standardised kerbside glass collection (often a separate crate or bin) accepts clean glass bottles and jars only. Broken drinking glasses, window panes, mirrors, Pyrex, ovenware and ceramics are not the same type of glass — they have different melting points and chemical compositions, so even a single broken wine glass or dinner plate can ruin a batch of recyclable bottle glass. As a rule, if it's not a bottle or jar, keep it out of the recycling.

So where does it go? Broken glass and ceramics generally belong in your red general-waste bin, but they must be wrapped first to prevent injury. Wrap shards in several layers of newspaper, or seal them inside a cardboard box or an old container, then tape it shut. Label it clearly — a quick "broken glass" written on the outside warns anyone who handles the bag. Never put loose glass straight into a rubbish bag where it can slice through the plastic and cut hands.

For larger or trickier items, your local transfer station is the best bet. Big sheets of window glass, mirrors, broken basins or large quantities of ceramic tiles can usually be dropped off there, sometimes for a small fee. Some transfer stations and community recycling centres also sort hardfill or rubble, and clean ceramic and tile offcuts may be accepted as hardfill rather than landfill — it's worth ringing ahead to ask, as this varies by area.

Before you bin anything, consider whether it can be reused or rehomed. Intact but unwanted crockery, vases and glassware are gladly received by op shops, and chipped terracotta pots can be broken down for drainage crocks in the garden. Broken ceramics also make excellent crushed drainage material at the bottom of planters, and tile fragments are popular for mosaic and craft projects shared through community groups and online buy-nothing pages.

The practical takeaway: keep broken glass and ceramics out of your yellow recycling, wrap and label sharp pieces before they go in the red bin, and take bulky loads to a transfer station. Rules around hardfill and glass crates differ between councils, so a quick check of your local council website will confirm exactly what your area accepts — and a few minutes of careful wrapping keeps everyone safe.