The results of a recent Israeli study suggest that mattresses made of polyurethane foam, and therefore also memory foam, are a significant source of volatile and semi-volatile organic compounds.
Most of the VOCs identified are related to the polyurethane manufacturing process and appear in all mattresses tested. A clear exception was the release of flame retardant additive (TCPP) only from the baby mattress, which raises the question of the benefit of adding flame retardants to these mattresses.
The study was funded by the Israel Environmental Health Foundation.
VOC pollution in our room
Today, exposure to volatile organic compounds VOCs and semi-volatile organic compounds is unavoidable due to the abundance of emission sources. Links to cancer, asthma, and developmental problems in children are just a few of the potential risks from exposure to VOCs.
High levels of VOCs are present in our atmosphere due to industrial chemicals. However, the home environment and the bedroom are also considered to be an important source of exposure.
In the bedroom you can be exposed to pollutants organic (bacteria, fungi, etc.), physical (particles) e chemists (VOC, flame retardants, plasticizers, etc.).
The particular interest in the bedroom regarding exposure to VOCs stems from certain factors such as:
- The time we spend in this environment averages more than 30% of 24 hours for young people and adults and more than 50% for infants.
- The presence of many sources of VOC emissions from mattresses, sheets and other furniture.
- Reduced bedroom ventilation at night.
Previous studies indicate that mattresses in general and polyurethane foam in particular are a significant source of VOC emissions. Environmental conditions during sleep can affect VOC emissions in this microenvironment.
High temperature due to human metabolism, high humidity and CO2 concentrations, resulting from human perspiration and respiration, create an environment capable of varying VOC emission rates.
Also, reduced ventilation in the bedroom and around the sleeping person, such as sleeping fully wrapped in a blanket, leads to higher concentrations of VOCs.
Due to the particular concern about children’s exposure to VOCs, previous studies have focused only on emissions from crib mattresses and ancillary products. The results indicated emissions of a long list of VOCs, including phthalates and flame retardants.
The new Israeli study focused on VOC and SVOC emissions from different children’s polyurethane foam mattresses, including quantification of emission fluxes, estimation of their sensitivity to environmental conditions (i.e. i.e. temperature, relative humidity and elevated CO2 levels, and presence of mattress covers) and assessment of resulting exposure levels.
To this end, the mattresses were tested in two parallel chambers, comparing two sets of environmental conditions in each experiment. The VOCs emitted by the chambers were continuously collected using absorbent tubes which were then analyzed by chromatography.
The results of the Israeli study
The results presented focus on 18 different VOCs that were identified with very high certainty with the NIST mass spectra library, then verified and quantified using external analytical standards.
The highest emission fluxes in all the mattresses tested were obtained for the2-Ethylhexanoic acid, reaching in some cases more than 190 μg/(m2 h). 2-EHA is a common catalyst in polyurethane production and its presence is therefore not surprising.
Two additional bunkers, formaldehyde And acetaldehyde, were frequently detected with flow rates of the order of a few μg/(m2·h). These aldehydes can come from the production process of PUF29 and/or from the degradation of other organic precursors.
Unlike the aforementioned carbonyls which were found in emissions from almost all mattresses, high emissions of hexanal were observed only from the bed mattress (LDI). It is possible that hexanal was used as an additive to phosphate flame retardants, which were also detected in this mattress.
Tris(1-chloro-2-propyl) phosphate (TCPP) is a flame retardant added to highly flammable polyurethane mattresses. In the current study, TCPP was only detected in emissions from the baby mattress, which by Israeli law must contain flame retardants.
Under bedroom conditions, the flux of TCPP produced by this mattress was on the order of 10,000 ng/(m2·h). This value is much higher than the flow rate measured previously at 23°C (12 ng/(m2h)), but very similar to the flow rate observed by polyurethane foam for padding (7700 ng/(m2h)).
TCPP has reproductive and developmental effects on human health and possibly even carcinogenicity. Given the amount of time babies spend sleeping and these potential negative health effects of TCPP, its detection in the airflow above the mattress, with an area-specific emission flow of order of μg/(m2 h), raises a question about the benefit of adding such a flame retardant to mattresses.
Emissions of were also observed in all mattresses tested aromatic compoundsincluding compounds such as benzene, toluene, xylenes and ethylbenzene known to have toxic effects on health.
Four other aromatic compounds potentially hazardous to health were detected in this study. L’butylated hydroxytoluene is a synthetic, high volatility phenolic antioxidant used for the stabilization of polyurethane foam. As additives in polymer matrices, these antioxidants can escape through abrasion and volatilization.
In recent years there has been growing concern about the widespread use of butylated hydroxytoluene (including in food and cosmetics) due to some studies suggesting its potential carcinogenicity.
The 2,6-ditert-butyl-1,4-benzoquinone, a transformation product of butylated hydroxytoluene, represented emission fluxes of the order of 300-3000 ng/(m2h). 2,6-ditert-butyl-1,4-benzoquinone has been shown to have negative toxic effects even at rather low concentrations, causing internucleosomal DNA fragmentation by H2O2 and generation of oxygen radicals.
The results of the Israeli study suggest that polyurethane mattresses are a significant source of VOCs. Since the analysis only looked at a few specific substances, the exposure to the actual concentration of VOCs in the bedroom is expected to be even higher.
Most of the VOCs identified are related to the polyurethane manufacturing process and appear in all mattresses tested. A clear exception was the release of flame retardant additive (TCPP) only from the baby mattress, which raises the question of the benefit of adding flame retardants to mattresses.
The Israeli study
Emissions of volatile organic compounds from polyurethane mattresses under varying environmental conditions
by Kira Oz, Bareket Merav, Sabach Sara and Dubowski Yael
Civil and Environmental Engineering, Technion, Israel Institute of Technology, Haifa 3200003, Israel
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