Glass is very easy to recycle; waste bottles and jars can be melted down and used again and again.
You simply toss old glass into the furnace with the ingredients you're using to make brand-new glass.
Most of the metal we throw away at home comes from food and drink cans and aerosols.
Typically food cans are made from steel, which can be melted down and turned into new food cans.
Drinks cans are generally thinner and lighter and made from aluminum, which can also be recycled very easily.
Mining aluminum is a very energy-intensive and environmentally harmful process.
That's why waste aluminum cans have a relatively high value and why recycling them is such a good thing to do.
People have been reusing this traditional, sustainable material for as long as human history. Waste wood is often turned into new wooden products—such as recycled wooden flooring or garden decking.
Old wooden railroad sleepers (now widely replaced by concrete) are sometimes used as building timbers in homes and gardens.
Waste wood can also be shredded and stuck together with adhesives to make composite woods such as laminates.
It can also be composted or burned as a fuel.
In the early 1970s, photocopier manufacturers got scared that we would stop using paper and turn into a "paperless society." Not much chance of that! Forty years later, the bad news is that we're producing more paper than ever before. But the good news is that we're recycling more as well. Unlike some materials, paper can be recycled only so many times. That's because it's made from plant fibers that become shorter during paper-making. When they're too short, they no longer make decent paper. In practice, this means some new paper always has to be added during the papermaking process.
Photo: Shredded paper, bagged up and awaiting recycling. Photo by Ron Fontaine courtesy of US Navy.
One problem with recycling paper is that not all paper is the same. White office printer paper is made of much higher quality raw material than the paper towels you'll find in a factory washroom. The higher the quality of paper waste, the better the quality of recycled products it can be used to make. So high-grade white paper collected from offices can be used to make more high-grade white recycled paper. But a mixture of old newspapers, office paper, junk mail, and cardboard can generally be used only to make lower-grade paper products such as "newsprint" (the low-grade paper on which newspapers are printed). Corrugated cardboard (which is held together with glue) is harder to recycle than the thin cardboard used to package groceries.
Waste documents are usually covered in ink, which has to be removed before paper can be recycled. Using bleach to de-ink papers can be an environmentally harmful process and it produces toxic ink wastes that have to be disposed of somehow. So, although recycling paper has many benefits, it comes with environmental costs as well.