Crib Mattresses Emit High Rates of Potentially Harmful Chemicals, Cockrell School Engineers Find

April 2, 2014

Editor's note from UT Austin media relations office on funding: As noted in the release, this study was funded by the U.S. National Science Foundation (NSF) and the Nordic Research Opportunity program, a joint program between NSF and the Finnish Funding Agency for Technology & Innovation (Tekes).

AUSTIN, Texas — In a first-of-its-kind study, a team of environmental engineers from the Cockrell School of Engineering at The University of Texas at Austin found that infants are exposed to high levels of chemical emissions from crib mattresses while they sleep.

Analyzing the foam padding in crib mattresses, the team found that the mattresses release significant amounts of volatile organic compounds (VOCs), potentially harmful chemicals also found in household items such as cleaners and scented sprays.

The researchers studied samples of polyurethane foam and polyester foam padding from 20 new and old crib mattresses. Graduate student Brandon Boor, in the Cockrell School’s Department of Civil, Architectural and Environmental Engineering, conducted the study under the supervision of assistant professor Ying Xu and associate professor Atila Novoselac. Boor also worked with senior researcher Helena Järnström from the VTT Technical Research Centre of Finland. They reported their findings in the February issue of Environmental Science & Technology.

The researchers found:

  • New crib mattresses release about four times as many VOCs as old crib mattresses.
  • Body heat increases emissions.
  • Chemical emissions are strongest in the sleeping infant’s immediate breathing zone.

The researchers concluded that, on average, mattresses emitted VOCs at a rate of 87.1 micrograms per square meter per hour, while older mattresses emitted VOCs at a rate of 22.1 micrograms per square meter per hour. Overall, Boor said crib mattresses release VOCs at rates comparable to other consumer products and indoor materials, including laminate flooring (20 to 35 micrograms per square meter per hour) and wall covering (51 micrograms per square meter per hour).

Boor became motivated to conduct the study after finding out that infants spend 50 to 60 percent of their day sleeping. Infants are considered highly susceptible to the adverse health effects of exposure to indoor air pollutants.

“I wanted to know more about the chemicals they may inhale as they sleep during their early stages of development,” he said. “This research also helps to raise awareness about the various chemicals that may be found in crib mattresses, which are not typically listed by manufacturers.”

The 20 mattress samples are from 10 manufacturers. The researchers chose not to disclose the names of the manufacturers studied so that their results could draw general attention to the product segment without focusing on specific brands.

At present, not much is known about the health effects that occur from the levels of VOCs found in homes, according to the U.S. Environmental Protection Agency.

Among the many chemicals considered VOCs are formaldehyde, benzene, toluene, perchlorethylene and acetone. The crib mattresses analyzed in this study did not contain those organic compounds.

The researchers identified more than 30 VOCs in the mattresses, including phenol, neodecanoic acid and linalool. The most abundant chemicals identified in the crib mattress foam, such as limonene (a chemical that gives products a lemon scent), are routinely found in many cleaning and consumer products.

Chemist and indoor air quality expert Charles J. Weschler, adjunct professor in environmental and occupational medicine at Rutgers University, said he does not think the levels of chemical concentration found in the mattresses are alarming, but he considers the research valuable.

“It’s good to be alerted to the fact that crib mattresses are a significant source of chemicals in an infant’s environment,” said Weschler, who noted crib mattresses might one day be analyzed for noxious chemicals as a result of such research.

The researchers found that VOC levels were significantly higher in a sleeping infant’s breathing zone when compared with bulk room air, exposing infants to about twice the VOC levels as people standing in the same room. Additionally, because infants inhale significantly higher air volume per body weight than adults and sleep a longer time, they experience about 10 times as much inhalation exposure as adults when exposed to the same level of VOCs, the researchers said.

“Our findings suggest the reuse of an older crib or an extended airing-out period may help reduce infant VOC exposures,” said assistant professor Ying Xu.

Although used mattresses may appear to be a good alternative, the researchers noted that older mattresses might contain other harmful chemicals such as flame retardants now banned in mattress foams.

Understanding the sleeping environment is important to the health of infants and adults, added Richard Corsi, chair of the Department of Civil, Architectural and Environmental Engineering.

“We need to better understand the complex sleep microenvironment to improve it and reduce the harmful effects of related pollutants on infants,” Corsi said.

The National Science Foundation and the Nordic Research Opportunity program funded the project. Boor conducted the research in Finland, where he currently lives.

The University of Texas at Austin is committed to transparency and disclosure of all potential conflicts of interest. All UT investigators involved with this research have filed their required financial disclosure forms with the university. None of the researchers have reported receiving any research funding that would create a conflict of interest or the appearance of such a conflict.

Notes for Parents

  • Findings suggest reuse of an older crib or an extended airing-out period may help reduce infant VOC exposures.
  • Reuse of crib mattress must be considered carefully because older mattresses might contain toxic substances, such as flame retardants, that have been banned.

For more information, contact: Sandra Zaragoza, Cockrell School of Engineering College of Engineering, (512) 471-2129.

13 Comments to "Crib Mattresses Emit High Rates of Potentially Harmful Chemicals, Cockrell School Engineers Find"

1.  joan said on April 2, 2014

So what do we use for mattresses for infants in their cribs?? Is there an alternative?

2.  Carol said on April 2, 2014

I have been concerned about VOCs and mattresses for 30 years. We need to get back to cotton mattresses, without chemicals. All the sleep problems now - I think many are due to VOCs and also polyester mattresses.

3.  Andrea Jones said on April 2, 2014

would it help to put a padded fitted cover over mattress

4.  Philip Fairye said on April 2, 2014

Were any of the mattresses Green Guard Certified?

5.  Jan sandford said on April 3, 2014

I want to purchase a new mattress for my first grandchild. Would wrapping the mattress in plastic help. How long do you suggest the mattress be aired out before use. Thanking you in advance

6.  Philip Fairey said on April 4, 2014

When is the study going to be released? There is significant lack of scientific approach by shielding the names of the mattresses tested. You are causing a stir in the children's product industry that could be avoided with appropriate disclosure. As it stands you have released information that would indicate "ALL CRIB MATTRESSES" are bad. There are millions of parents that need appropriate guidance and help with product selection and you have created a blanket negative on the product category. This is irresponsible at best.

7.  DL said on April 10, 2014

Interesting article

8.  University Communications said on April 14, 2014

Joan: Thanks for your comment. We have a few practical recommendations for you and other parents: a) If you buy a conventional crib mattress, air it out for several months before using it. This way you will avoid the peak or maximum VOC (volatile organic compound) emissions from the product. Alternatively, you could re-use a crib mattress, as the VOC emissions will be lower. There are, however, some other issues to consider when re-using a mattress: The mattress may contain various banned chemicals, including plasticizers and flame retardants, if manufactured before a certain date. It is also important to serialize the mattress cover and inspect the foam for any mold growth. b) Purchase a crib mattress manufactured with natural materials, e.g. wool, cotton, latex. Wool has some natural fire retardant abilities, so chemical flame retardants may not be required. There are, however, allergy concerns when using products containing wool, cotton, and latex. c) Improve ventilation in the child's bedroom or nursery and use a portable or personal air cleaner with an activated carbon filter. This will lower the VOC concentrations in the air and reduce exposures. Also, it may be possible to put an activated carbon or highly absorbent material, such as wool, on top of the crib mattress to absorb chemicals released from the mattress over time, but we have not done any research in this area.

Brandon Boor
Graduate Student
Department of Civil, Architectural and Environmental Engineering

9.  University Communications said on April 14, 2014

Andrea, thanks for your comment. Depending on the material, it may not be good to put a padded cover over your crib mattress. If the padding is polyurethane or polyester foam, it will likely emit VOCs in the same manner as the crib mattress. Typically, there will be a tag on the cover listing the material composition of the product. If the padding is manufactured out of an absorbent material, such as wool or cotton, it will help trap some the VOCs released from the mattress (act as a sorptive sink or passive air cleaner to some extent). However, we have not tested any fitted padded covers for chemical emissions, and have not explored the impact of using absorbent materials to reduce VOC concentrations in the infant sleep microenvironment.

Brandon Boor
Graduate Student
Department of Civil, Architectural and Environmental Engineering

10.  University Communications said on April 14, 2014

Philip: To the authors' knowledge, none of the new or used crib mattresses examined in this study were labeled as "GreenGuard Certified" or certified by a similar labeling company. The study has been published in Environmental Science & Technology, a high impact peer-reviewed scientific journal: http://pubs.acs.org/doi/abs/10.1021/es405625q. The new crib mattresses purchased for this study are representative of those found in any retail store in the U.S. We feel it is not appropriate to disclose the manufacturers of the particular mattresses we tested as we are doing fundamental research on the infant sleep microenvironment. The rate at which VOCs are released from a mattress, and the presence of plasticizers or flame retardants in the mattress, will vary from one manufacturer to another. That being said, it is reasonable to expect similar levels (order of magnitude) of VOC emissions among most crib mattresses that are manufactured with polyurethane or polyester foam and a plastic cover.

Brandon Boor
Graduate Student
Department of Civil, Architectural and Environmental Engineering

11.  David said on April 14, 2014

1. Who paid for the study?

2. How come no context was provided? At what levels do parents have to worry? Are some VOCs harmless? Which VOCs are the most dangerous? What brands have what VOCs?

3. After six months of letting it "air out" is sufficient, then if a family has had a particular mattress for longer than that time, then the danger has passed?

4. Would a HEPA filter cycling the air in the room 6x per hour be an effective mitigator? If so, then how come that tidy bit of information was not included?

Without context, the study and the "news" that delivers the study results, are nothing more than a paid advertisement by the organic mattress industry.

Could they be right about the danger? Absolutely. But there is no context from which to judge. Until more neutral research and unbiasd peer reviewed work is completed, this smells like and probably is complete bs.

12.  Trina Masepohl said on April 22, 2014

Wonderful research. I look forward to reading the full study. Using a GreenGuard certified crib mattress is an excellent start to creating a healthier sleep environment of your baby. You can find out more at greenguard.org. No, I am not affiliated with them, but am a former engineer myself, now interior designer, and I encourage parents to use products in their children's rooms that have some level of third-party green certification. GreenGuard is just one such certification system.

Regarding the comments about "unbiased peer reviewed work", that is the whole point of journal publications. Before research like this can ever be published, it undergoes a series of critical reviews and feedback. Environmental Science and Technology is a peer-reviewed journal and a highly-regarded one at that. Anyone familiar with the Precautionary Principle will understand the importance of this research. Physicians like Dr. Philip Landrigan at Mt. Sinai's Icahn School of Medicine and scientists like Dr. Heather Stapleton at Duke University have done similar research to identify potential chemical hazards to our children. No conspiracy theories here. This is pretty basic stuff: If you want to create a healthier environment for your kiddos, limit the chemicals you bring into your home.

How much more research do we need before we create simply healthier spaces for our kids? It took the U.S. decades to outlaw lead in gas and our children suffered greatly as a result. Sometimes taking a Precautionary approach is simply the right answer. If you're interested, more at http://www.mixxmodern.com.

13.  Cheryl said on April 30, 2014

We purchased what is essentially a giant plastic pillow case for our crib mattress from Australia via the internet. They have had a campaign there to wrap all mattresses and claim no SIDS deaths have occurred in wrapped mattresses. Makes sense to me!