Rock-A-Bye Baby Gone Bad: The Dangers of Crib Mattresses

Anyone with experience raising a baby knows that they sleep a lot. Sure, they DON’T sleep a lot as well, leaving mom and dad often very sleep-deprived the next day.

In the first three years of life, babies are known to sleep around 12-13 hours per day, compared with 8 hours (or less, for many of us with busy schedules) for adults.

Significantly, the mattress they sleep on can be a lot more dangerous than a dirty diaper.

One recent research study showed that the mattresses used in babies cribs are a big source of potentially hazardous airborne chemicals called volatile organic compounds (VOCs), exposing the sleeping infant to harmful chemical compounds that have been linked to a wide range of health problems1.

The average run-of-the-mill crib is made up of a layer of polyurethane or polyester foam padding within a waterproof plastic cover for protection.  Since much of the chemicals used to create these crib mattresses are plastic-based, studies have found that these cribs are likely sources of VOCs, and are linked to sensory issues, breathing problems, and reduced airflow in mice2.

Intake of VOCs in infants may be greater than it would be for an adult experiencing the same level of exposure.  Per day, babies inhale an order of magnitude more air than adults do, suggesting that infants will inhale significantly more VOCs than an adult in the same room.

Other studies have found that infant exposure to VOCs is linked to negative impacts on the developing immune system of the child, increased risk of asthma, and increased risk of allergies in exposed children3.

Using controlled environmental chambers to avoid any contamination from the outside environment, this most recent study examined both brand new and used mattresses at two different temperatures (23oC and 36oC) and if VOCs are emitted at levels that are potentially harmful for the sleeping baby.  Additionally, since getting a real baby for this kind of test is highly unethical, the researchers used a “baby dummy” instead that was set at the approximate temperature of a living breathing infant to get as realistic as possible of a scenario.

Photo By lmcreglow (Flickr: Cat in bed) [CC-BY-2.0 (], via Wikimedia Commons

Photo By lmcreglow (Flickr: Cat in bed) [CC-BY-2.0 (], via Wikimedia Commons

The study confirmed what previous studies have found, in that as the temperature of the room increased from 23oC to 36oC, VOCs emitted from the mattresses increased significantly.  In fact, VOC levels were about double at 36oC than what they were at 23oC, suggesting that VOC exposure may be greater during the summer than during the winter (provided the room does not have air conditioning).

The study also found that new crib mattresses emitted about 4 times higher levels of VOCs than older used mattresses.

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Additionally, many of the mattress covers were able to reduce the VOC levels in the air around the crib, however warned that a couple of the mattress covers actually INCREASED VOC levels in the air.

Lastly, depending upon the material, some mattress covers can act like a “VOC sink”, absorbing a lot of the compounds that would have otherwise escaped into the air.

Based on the VOC levels emitted by the crib mattresses during the experiment and how much the typical infant breathes while sleeping in the mattress, the sleeping baby could inhale 1μg/kg of VOCs (depending upon the temperature of the room).  If an adult were in the same room breathing the same air, they would inhale significantly less VOCs than the infant.

What can you do?

Many crib mattresses are made of plastic-based materials, and studies have linked these materials to increased VOC levels in the air around the crib.  This same source of VOCs has been linked to health problems in young children, including increased risk of asthma and allergies.  What can you do to help avoid or at least reduce the amount of VOCs your baby inhales while it sleeps?

  1. Maintain good air flow throughout the room.  If you live in a climate that allows it, keep the windows cracked a little and run a ceiling fan to help move any VOCs emitted from the mattress away from the sleeping baby.
  2. Use an older mattress.  This comes with some caveats, as some older mattresses actually contain some harmful flame retardants that also have been shown to emit dangerous VOCs in the air4.  If using an older mattress, use one that doesn’t have these flame retardants added (specifically polybrominated diphenyl ether or PBDE).
  3. Let the mattress “air out”.  Studies have shown VOC levels are significantly higher in brand new mattresses and gradually decrease over time.  Think about purchasing the mattress for your crib earlier on in the pregnancy and leave it out (and out of any packaging) in a well-ventilated room with bedding until it’s baby time.
  4. Find mattresses that are GreenGuard certified. Products that receive a GreenGuard certification5 must be made to reduce the harmful chemicals that contribute to indoor air pollution, like the VOCs emitted by plastic-based mattresses.  I can’t say for certain if these products are completely VOC-free, however, they should be significantly reduced.

Further reading:

  1. Boor, B.E., Järnström, H., Novoselac, A., and Xu, Y. 2014. Infant Exposure to Emissions of Volatile Organic Compounds from Crib Mattresses. Environmental Science and Technology 48: 3541-3549.
  2. Anderson, R.C., and Anderson, J.H. 2000. Respiratory toxicity of mattress emissions in mice. Archives of Environmental Health 55(1): 38-43.
  3. Franklin, P.J. 2007. Indoor air quality and respiratory health of children. Paediatric Respiratory Reviews 8: 281-286.
  4. Stapleton, H.M., Klosterhaus, S., Keller, A., Ferguson, P.L., van Bergen, S., Cooper, E., Webster, T.F., and Blum, A. 2011. Identification of flame retardants in polyurethane foam collected from baby products. Environmental Science and Technology 45(12): 5323-5331.
  5. GreenGuard Certification website information.
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