Your baby's crib should have the firmest mattress available. Smothering has been implicated in cases of crib death, and a mattress that isn't extremely firm is a mattress into which a baby's face can sink. Not only is there a risk of your baby getting his nostrils pressed against the mattress once he is old enough to roll over (remember to always put baby to sleep on his back), but there is also the danger that, with his nose into a soft mattress, he could keep breathing but breathe his own exhaled carbon dioxide over and over and not get much oxygen. In this situation, he could become dopey and not have the strength to cry or struggle for air. This is a mortal hazard.

If your crib is a hand-me-down, either from your own previous child or from a friend's child, invest the money to buy a new mattress for it. It's well worth the cost.

Besides being sure that the crib's mattress is firm enough, you also need to be sure that it fits tight to the side of the crib. You should not be able to fit more than two fingers between the mattress and the side of the crib. The slats of the crib should be no more than 2⅜ inches apart, as a precaution against your baby putting his head between the slats and getting wedged or strangled. Be sure there are no loose, missing, or broken slats or hardware. There should be no corner posts over 1/16 inch high and no cutout designs in the headboard or footboard.

Painted Cribs

Be sure that there is no paint flaking from the crib. This is primarily a hazard with old cribs, but if you're using a family heirloom or a thrift store purchase, you need to be alert for this hazard. If this is a family heirloom or other older crib and it's painted, make very sure it's not painted with lead-based paint. If you're not able to verify that the crib was manufactured in the post lead-based paint era and it does have paint on it, be safe and strip the paint off and then repaint it.

Generally, lead-based paint should be suspected in any crib dating back to the 1970s or earlier, but there is no hard-and-fast rule. A crib dating from the 1980s could have been repainted with lead-based paint by someone who had a can of it lying around and was unaware of the danger. If you must use an old crib, have a sample of the paint tested first.

Though family heirlooms have great sentimental value, you're safest with a new crib in great condition. If you're looking to buy a crib at a thrift store to save some money, by the time you buy a new mattress and new bumpers and you strip off any suspect paint and repaint the crib, you won't have saved that much money. So consider just investing in the safety and security of a new crib.

Another hazard to watch out for is decorative knobs or other decorative fixtures that stick out from the crib itself. Once your baby learns to stand, he is at risk from any decorative fixture on the crib that might poke his eye, come loose and be swallowed, or present any other hazard, such as rough edges on which he can cut or scrape himself.

There's a lot to be aware of in buying a crib (or in accepting a hand-me-down crib). Most recently manufactured cribs conform to the necessary safety measures, but it pays to be a wary consumer even if you're buying a new crib. With an old crib, especially a family heirloom (your family's or someone else's) that's been around for a while, there's a greater chance that not all safety precautions were observed.

If your crib is mesh-sided, the Consumer Products Safety Council recommends the following precautions, which also apply to mesh-sided playpens: