We have lots of rules to live by—some optional, some not. There’s the five-second rule (for picking up food that fell on the floor); the one-day rule (for texting that heart-eyes-emoji guy from the night before); and of course, the eight-hour rule (for changing your tampon).
But if you forget to switch, or you’re stuck somewhere you don’t have a spare tampon, what’s the worst that can happen? We’ve all heard about the apparent price you pay for laziness—the terrifyingly named toxic shock syndrome—but we’ve also heard it’s super rare. So is it a real risk, or are we unnecessarily freaking out in the final hours?
Grasping at Threads 
The long and short of it: Toxic shock syndrome (TSS) is extremely rare. It affects around one in 100,000 women, says Wendy Chang, M.D., an OB/GYN and scientific director of Southern California Reproductive Center. As any tampon box will tell you, TSS is the result of an infection by two major kinds of bacteria, staphylococcus aureus (staph) and group A streptococcal (strep). Leaving a tampon in after the recommended eight-hour limit ups the risk, as does choosing the super-mega absorbency option (the more material, the higher the risk).
Turns out, everyone actually has some trace of staph bacteria on …