Are there any health/fire/safety risks associated with adding bleach to the rinse cycle (when already used in the wash cycle) to whiten dingy cleaning rags?
Thanks for sending in your question — it’s a very interesting one! There’s no fire risk with Clorox® Regular Bleach2. From the product’s Material Safety Data Sheet, Fire and Explosion Data is as follows:
Health risks associated with adding bleach to the final rinse cycle would be limited to potential skin sensitivity of people who use the rags in the future, and that would vary between individuals. The biggest issue (and the best reason to not add bleach to the final rinse cycle) is residual bleach left behind in the washer that could carry over to the next wash load, meaning you could get bleach spots on items not safe for bleach!
Adding an extra rinse cycle would eliminate the “bleach residue” problem, but I would recommend using a combined bleach pre-soak and bleach + detergent wash instead. Start by rinsing the rags, and then soaking them for 5 minutes in a bleach solution of ¼ cup Clorox® Regular Bleach2 per gallon of warm water. Drain the soaking solution and then wash the rags in hot water using a good powdered detergent + ¾ cup Clorox® Regular Bleach2.