I'm not a chemist but my two cents because I studied a course of Industrial Inorganic Chemistry in my college. My professor of that course used to say Hydrogen Peroxide is a very strong carcinogen. So I hate every Tom Dick n Harry that yaps about the goodness of Hydrogen Peroxide on YouTube or elsewhere without mentioning that it will give you cancer even in small amounts. And yes UV disintegrates the fibres so the more you keep your clothes in the sun or in UV then they will look old. Source: I live in India with too much UV andif I keep anything under the sun for a couple of days then it looks old or atleast no more new to be worn fashionably.

Your professor was teaching Industrial chemistry. At industrial (undiluted) strengths, there aren’t many chemicals that can’t damage tissue or potentially cause cancer. Constantly breathing the undiluted fumes or other exposures will certainly carry some risk in an Industrial application.

Washing clothes in a dilute peroxide solution is not going to cause cancer, therefore simply walking outside to hang your clothes carries substantially more cancer risk than the use of Hydrogen Peroxide.

Saying it causes cancer in “small amounts” is a bit like shouting at someone that stepping on a twig is destroying the entire forest…while standing next to an inferno.

Doesn't seem to be on the IARC's lists of known and probable carcinogens: https://www.cancer.org/cancer/risk-prevention/understanding-...

I'm also not a chemist... but I do have a PhD in mtls science from a top 10 program. My dissertation was on computational chemistry on organic compounds.

You're 100% right.

As long as the photon is energetic enough, it can cause a radical and therefore break a chemical bond.

Brighter the sunlight, more peroxides (or radicals) made, more damage to your skin or your cloth's fibers.

This is also why anti-oxidants are so effective at protecting the body, why inflammation is so damaging (body produces peroxides to eliminate what it believes is a threat), over consumption of food, too much/little exercise, etc. they all affect peroxide concentration or their halflife.