In September, a ban on triclosan in over-the-counter antiseptic soaps, gels and wipes went into effect in the US. But the antibacterial ingredient is still allowed in toothpastes for its reported ability to reduce gum inflammation, plaque and cavities. Now a study has found that triclosan accumulates in toothbrush bristles and elastomer parts, and is readily released when users switch toothpastes, potentially prolonging users’ exposure to the compound.