The tail is made of safe synthetic fiber, and the entire device is RoHS certified. However, for safety reasons, please avoid letting your cat play with it alone and be sure to supervise and accompany your cat throughout playtime. If you notice that the tail has become frayed or tangled, we recommend that you carefully cut off the frayed or tangled end with a clean pair of scissors and then re-tie the end to restore your Wicked Mouse Neo to a usable condition.