Recycling and buying secondhand are all the rage, but some things are just dangerous to buy used. You are either buying a problem or taking a foolish risk.
While many people would assume used underwear and socks were the real worry, microbiologist Dr Heather Hendrickson says textiles that can be put through a good soapy hot wash are safe.
She's based at Massey University in Auckland and we are talking about secondhand textiles like sheets, pillow cases, or even more personal clothing like swimming togs, hats.
"Either the bacteria's membranes will be disrupted by the soap and or they are just washed away. Those things I wouldn't be that concerned about."
Even if they weren't properly cleaned, she says most bacteria aren't pathogens.
"We are full of bacteria. We are all covered in bacteria and covered in microbes, so what is the point where you suddenly think 'oh now I am really concerned'. These bacteria aren't going to harm you."
A more likely source of harmful pathogens will come from the person with a cold at the next desk at work, or from poorly cooked meat.
However, she says feeling "icky" about using other people's intimate clothing and bedding makes sense.
"That ick factor we have, even if it is not always scientifically based, is still completely valid because it is something that we have evolved as a species that kind of warns us off dangerous situations. The danger might be there or not but it doesn't hurt to be cautious. So having that ick factor is a beautiful part of evolution."
Used buys to avoid
Stuff NZ motoring writer Rob Maetzig says don't buy any secondhand car that the owner can't guarantee has had its airbag checked. Maetzig says there are still tens of thousands of cars that remain subject to the Takata airbag recall. Maetzig says that should be checked out as part of the buying process, particularly when the transaction is private-to-private. A list of cars covered by the recall can be found at Product Safety Australia.
Never buy a used cycle helmet. Firstly helmets need to meet one of five different standards to be legal on the road in Australia and need a sticker inside saying which one. Helmets need to be tried on to fit properly in order to work properly. The most significant risk lies in buying a helmet that has been damaged or worn out, because this can seriously reduce its safety. Even minor damage on the surface of a helmet can signal bigger problems in the structure underneath.
Stuffed toys fall into the category of "hard to clean properly". A few years ago cleaning company Dettol said its research revealed cuddly toys had the highest levels of bacteria in the family laundry basket and three out of four teddy bears weren't washed after a child was ill. Teddies were swab tested and the results were what you'd expect from toys that are dragged around and gummed by toddlers. Norway launched a shock campaign with teddy bears looking like Adolf Hitler and Kim Il Jong to urge families to wash teddies four times a year for health reasons.
Sleeping on a well-worn mattress with the groove and stains of a previous owner rates high in the ick factor, but unseen dust mites and bed bugs are a much better reason to avoid used mattresses. Dust mites feed on dead skin and can cause allergies. Bed bugs can also be in old mattresses. Shailendra Narayan, of Pest Control Services in Wellington New Zealand, says bed bugs have been known to survive up to a year without a meal in cool conditions and love cosy cracks and crevices. New research shows bed bug excrement is loaded with histamines that can trigger itchiness, watery eyes, sneezing, headaches, and asthma attacks.
Well-worn shoes are a bad secondhand buy, says podiatrist Bruce Baxter. This especially goes for running shoes. When a shoe is well worn, it has changed to fit the foot of the owner. It almost certainly won't fit the foot of a new owner, and that could cause damage. "There's also the likelihood if the previous owner has a fungal disease problem, you are also getting those spores."
The jury is out on whether non-stick cookware is perfectly safe or not. But most agree that not overheating pans above 260 degrees Celsius is the key to making sure the chemicals used to create the non-stick surface don't break down and get eaten with your food. The US Environmental Protection Agency says routine use is safe, but it is also working towards eliminating the synthetic chemical perfluorooctanoic acid which is used to make non-stick coatings. All that means is: do you know that old used non-stick pan is made of the latest, safest coatings and hasn't been overheated in its past life?