Buying used safely

It can be, NHTSA says, if you can tick every point on its checklist: never in a moderate or severe crash, labels showing its date and model, no recalls, all its parts, and its instruction book.

You need the date of manufacture and the model number to check for recalls and to tell whether the seat is too old. A seat without them fails NHTSA's used-seat checklist.

Contact its manufacturer with the model number and date: NHTSA notes that some recall problems can be fixed.

Contact the manufacturer first. NHTSA says some missing parts can be ordered, and the instruction manual can be ordered too.

NHTSA's checklist rules out any seat that has been in a moderate to severe crash, so ask about a secondhand seat's history before you buy it.

It can. The EPA advises checking secondhand furniture, beds and couches for any signs of bed bugs before bringing them home.

Look along seams, between cushions, under tags and in drawer joints for rusty or reddish stains, dark spots that smear like marker, tiny pale yellow shed skins, or live bugs.

Check its seams, piping and tags for bed bugs first. The EPA also suggests a cover that fully encases the mattress and box spring, which removes many hiding spots.

Yes. The CPSC's Anchor It campaign urges fixing furniture, TVs and appliances to the wall with an anti-tip device — a small hole in the wall that can prevent a tragedy.

The CPSC estimates about 11,300 children a year were treated in emergency rooms for tip-over injuries from 2017 to 2019, and 75% of child deaths involved a TV, alone or with furniture.

It is a law label listing what a mattress, pillow or upholstered item is filled with. It may be removed by the consumer — though mattress makers may ask for it with a warranty claim.

At home: 91% of reported tip-over deaths happened inside a home, and half of children's deaths were in bedrooms, the CPSC reports. Most involved a child climbing or pulling on furniture.

Not unless they are sold as unlocked. The FCC says a phone not specifically sold as unlocked is probably locked to one carrier, so check before you buy.

The carrier lock — software that stops a phone being activated on another company's network — has been switched off, so you can take the phone to a different provider.

Not always. Carriers use different frequencies and technologies, and the FCC warns that unlocking does not make a phone compatible with every network. Check the model with your carrier.

Ask the carrier it is locked to. Carriers that follow the CTIA code unlock eligible phones or reply within two business days, and may charge a reasonable fee if you were never their customer.

Yes. The FCC notes that tablets and other mobile devices can be locked to a network too; the carrier's unlocking policy explains how to free one.

Ask your mobile provider before you go. Networks differ from country to country, and even when calls work, data or texting might not, the FCC says.

A number, usually unique, that identifies the phone itself rather than its SIM card. If a phone is stolen, its owner's network can use the IMEI to blocklist it.

Dial *#06# on the keypad and most phones show it on screen. It is also printed on the handset, often on the SIM tray or under the battery.

Often not. A network can blocklist a stolen phone by its IMEI, and the block can reach other networks even when the SIM is swapped.

Not if the door is affected. The FDA says not to use a microwave whose door does not close firmly or is bent, warped or otherwise damaged, because a damaged oven may leak microwave energy.

Check its manual first: the FDA notes that some microwave ovens should not be operated when empty.

Donate or recycle them — many makers and retailers run schemes — but first delete all your personal information, and take out batteries, which may need recycling separately.

No. The EPA says lithium-ion batteries should stay out of household trash and recycling bins; take them to a battery recycling drop-off.

One sold outside the maker's authorised sales channel, often imported from another country. It usually works the same, but the manufacturer may refuse warranty service on it.

Failure rates follow a bathtub curve: higher at first while faulty units and shipping damage show up, low and steady through a product's useful life, then rising as it wears out. Test a new purchase straight away.

At room temperature and part-charged — keeping a lithium-ion battery around 60–80% reduces its capacity loss. Stored fully charged or run completely flat, it is harmed.

Makers put lithium-ion self-discharge at about 1.5–2% a month, faster in warm places. A device stored for many months can run flat, so top it up now and then.

Yes. Swelling comes from gas building up inside the cell — a sign of breakdown that can lead to more heat, fire or even explosion. Stop using the device and do not charge it.

Packaging that shows clearly when it has been opened — foil inner seals, wrap around a lid, or break-away parts that cannot be put back. Check these before using anything you eat, drink or put on your body.

Often for a while: most food stays edible past its sell-by date, though its quality is no longer guaranteed, and how it was stored matters.