Recently, scientists at the University of Cincinnati in the United States studied the exposure of bisphenol A (BPA) in polycarbonate plastic bottles. They found that the release of BPA was not related to the old and new plastic containers, but was mainly affected by the temperature of the liquid in the containers. The researchers pointed out that when the two old and new polycarbonate beverage bottles were exposed to boiling water, the release rate of environmental estrogen BPA was 55 times that of previous exposure to room temperature water.
Researchers at the University of Cincinnati found that new and used polycarbonate beverage bottles release BPA in both cold and warm water at the same rate and at the same rate, except that BPA release levels are dramatically reduced when the bottle is placed in boiling water. The change.
For the same beverage bottle, BPA was released from the bottle at a rate of 0.2-0.8 ng/h before exposure to boiling water, and after being placed in boiling water, the release rate was increased to 8-32 ng/h, and the speed was increased by 15- 55 times. Dr. Belcher also emphasized that it is unclear what level of BPA is currently causing harm to humans, but he advises consumers to consider how cumulative environmental exposures harm their health.
The discovery of the University of Cincinnati caused widespread public concern about the safety of BPA. The bisphenol A industry believes that this finding lacks a comprehensive scientific basis. Recently, scientific groups and the government conducted a series of studies and comprehensive reviews on the safety of BPA, confirming that polycarbonate bottles can continue to be used safely.
The industry believes that, first of all, polycarbonate bottles can degrade, then the use of 9-year-old beverage bottles is certainly different from new beverage bottles; secondly, the increase in the release rate of BPA bottles containing boiling water is no longer news, because migration Accelerating the speed with increasing temperature is an obvious common phenomenon. This phenomenon has been confirmed in many previous tests concerning the release of BPA from polycarbonate bottles. Third, the University of Cincinnati pointed out that the use of boiling water bottles may have long-term effects. However, they only conducted a test on the speed of migration in boiling water. In order to test the safety of repeated use of polycarbonate bottles throughout their life cycle, researchers at the University of Athens conducted repeated tests on the release rate of BPA in polycarbonate bottles, demonstrating that the rate of BPA release in boiling water is indeed higher than that of low temperature water. However, after repeated use for 4 to 8 cycles, the BPA migration rate rapidly drops, even if boiling water is used in each cycle. This shows that the increase of the release rate of BPA in boiling water is only a transient phenomenon, and the speed will decrease rapidly when it is used continuously.