Most of us don’t even think about how we dispose of our old phones. With one in seven Australians upgrading despite owning fully-functioning devices, we really should think about our e-waste.

According to research by comparison site, finder.com.au, one third of phones will actually spend the rest of their days waiting in a drawer to be used for emergencies. With 15.3 million active smartphones, that’s over 5 million working handsets simply collecting dust, and possibly a little rust as well.

Although this is not ideal, it’s better than the 6% of smartphones which are thrown in the bin because they are no longer serviceable.

Mobile phones are filled with harmful and toxic substances such as arsenic, mercury, lead and copper. While phones only contain trace amounts of these compounds, these poisonous chemicals and metals can end up an environmental disaster when they end up in large quantities in landfill.

I know for some it’s hard to resist the temptation of upgrading to a new smartphone. So how do you know when it’s definitely time to purchase a new device?

The battery is weak (and a replacement doesn’t fix it)

If you find your battery only last a few hours, it’s probably time for a new phone. It’s worth looking into battery replacements, although with many phones having heavily sealed batteries this can be a costly exercise, and it’s not a rock solid guarantee to fix some battery problems. Sometimes it’s cheaper to just bite the bullet and purchase a new phone.

It’s unbearably slow

Perhaps your touch screen has started to lag, or every time you try to send a message your phone screen freezes. As time goes on your phone will become slow and sluggish. There’s no point in walking around with a temperamental phone that can’t even do the most basic of tasks.

It randomly shuts down

This is a no-brainer really. If your phone frequently shuts down mid-task, you need to purchase a new one. The random closing of apps, services and the whole system is definitely a serious pain point, especially if it leads to you missing important calls, emails or texts.

You’re on the 2G network

If you’re not already aware, late last year Telstra stopped servicing customers on the 2G network. This meant that roughly 100,000 people were cut off from making phone calls or sending messages from their existing handsets. If you’re with Optus or Vodafone and rock an old school (1990s early 2000s) handset, you’ll be faced with a similar problem. It’s a good idea to start thinking about upgrading your plans and handsets now.

If you’re in the market for a new phone, make sure you also consider how you’ll dispose of your old handset. Rather than keep it locked away and unused you could donate it to a family member or friend. Or if you’re up for making a little bit of cash instead, you could sell it to a mobile recycling service.

Just remember, there are a number of ways to dispose of your phone correctly, and chucking it in the bin with the rest of your day-to-day waste is not one of them.