Rubbish and recycling

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Batteries

Batteries have become an indispensable part of our daily lives. But we are also being told that batteries are hazardous and cannot simply be thrown into the rubbish. So what do you need to know about batteries?

There are two different types of battery - wet and dry ones.

Wet cell batteries are the ones you have in your car, boat and truck. They are generally referred to as lead-acid batteries and, as the name suggests, they contain lead and acid. Lead-acid batteries also come in a sealed version for more specialist applications, but the content is essentially the same. Such batteries can be recycled easily, and it is being done here in New Zealand. Many garages will accept old batteries, as will a number of retail outlets and of course, the HazMobile.

Dry-cell batteries are those that we put into everything from torches, remote controls, power tools, toys, toothbrushes and all the other wonderful inventions without which modern life would be very different. These come in two versions - one-way, or non-rechargeable, and rechargeable. There are also other types such as the small button batteries found in some digital cameras and hearing aids.

The concern about throwing batteries into the rubbish is that some batteries are a concentrated source of heavy metals such as lead (the lead-acid batteries mentioned above), cadmium or mercury. When these batteries find their way into the landfill, the heavy metals can leach out and contaminate the environment. Because heavy metals do not break down, they will be around for a long time and pose a danger for human beings and the environment. For example, cadmium is a human carcinogen and can also cause liver and lung disease, while mercury can damage the human brain, spinal system, kidneys and liver.

In general, all batteries can be recycled, but New Zealand does not have the facilities to do so safely. With the relatively small amounts of dry-cell batteries that are recovered it is unlikely to be economically viable to set up such places. This means we have to focus on those batteries that will do the most harm if they are not recycled and their heavy metals are extracted.

The rule of thumb is that rechargeable batteries should never be thrown into the rubbish as they're the ones most likely to contain heavy metals such as cadmium. The same goes for button batteries, because of their mercury contents. All rechargeable batteries can be taken to a HazMobile collection. The batteries received by the HazMobile are sorted into their different types, and the rechargeable ones are shipped to Europe for recycling - an expensive but safe way to dispose of them.

Ordinary non-rechargeable batteries such as alkaline, zinc chloride or zinc carbon batteries do not contain heavy metals any longer. Since the mid-1990s, mercury stopped being added to these batteries and the small amounts that an average household needs to get rid of can be put out with the general rubbish. However, if you are unsure about the type of battery you have, the HazMobile will take them all and sort them for you.

Visit the following websites for more information:

HazMobile - for collection dates, locations and times
Ministry for the Environment - for a downloadable battery fact sheet.

Published April 2008