Triclosan, an antibacterial agent stays in some over-the-counter toothpastes, accumulates in toothbrush bristles and easily enters the mouth if the user switches toothpaste varieties.
Baoshan Xing, an environmental chemist at the University of Massachusetts Amherst, explains, triclosan not found as an active ingredient in all toothpastes, but only in those marketed as antibacterial.
Researchers said, brushing with these products allow triclosan to accumulate in nylon bristles and other soft toothbrush parts.
In 2016, the U.S. Food and Drug Administration (FDA) banned triclosan products, but it allows in toothpastes. The FDA says, triclosan found in one brand was “effective in preventing gingivitis,” or gum disease.
Previous research demonstrated that triclosan has the potential to disrupt hormones in animals and humans, contribute to antibiotic resistance and cause severe toxicity to aquatic organisms.
Automated Brushing Simulator
For study, the researchers designed an automated brushing simulator to combine with intermittent manual brushing, simulated the recommended two-minute, twice a day brushing over three months of use.
Using standard artificial saliva, they tested 22 best toothbrushes, and a range of toothpastes, along with triclosan-formulated and triclosan-free ones.
The results showed more than one-third of the toothbrushes tested accumulated amounts of triclosan. It is equivalent to 7 to 12 doses of the amount used per brushing.
Toothbrushes with soft polymer “polishing cups” and “cheek tongue cleaners” absorbs high amounts of triclosan. Also points out the use of the brush led to larger accumulations.
The researchers also tested six different triclosan-formulated toothpastes. They found a similar pattern of accumulation when brushing with a typical triclosan-accumulating toothbrush.
The findings suggest that triclosan could find its way into the environment if contaminated toothbrushes are discarded.
Researchers also found several other chemicals, along with butylated hydroxytoluene (BHT), a controversial antioxidant used in some whitening toothpastes, accumulated in toothbrushes. They said, this issue not restricted to toothbrushes or dental hygiene products.
More information: [Environmental Science&Technology]