I understand that they fall within the UV-A range, but I find it hard to believe that they would be commercially available to consumers as common party lights if they were a health hazard. I’m not talking tanning booths levels here…
A lot of things sold in shops aren't safe but people are exposed to them daily. Nitrites and Nitrates are carcinogenic if ingested but are often found in tap water.
A herbicide called Glyphosate (Roundup, Weed Killer, etc) is extremely dangerous but can be bought from any supermarket, hardware store or garden centre, by children. This stuff is used all over parks, gardens, footpaths and people's yards but it is a serious safety hazard, and it does cause cancer.
Exhaust fumes from fossil fuel powered vehicles are toxic but billions of vehicles spew the stuff out every day and most people don't give it a second thought.
People still smoke even though it has been known to cause lung cancer for nearly 100 years. Alcohol is the same, causes all sorts of cancers as well as damages families and wastes heaps of police resources.
Half the chemicals in fish medications cause cancer but people still add them to their aquarium.
Vermiculite is used in horticulture to grow seedlings but it is often found in association with asbestos.
White asbestos has been found in talcum powder and the companies that make the stuff have known about it for over 50 years.