It will basically be fine. If something happens, will it still pass the quality inspection? Besides, Casio is not a no-name brand and will not be so irresponsible to consumers. Reputation is the primary productive force of an enterprise. Don't worry.
Attached information:
Substances that can emit fluorescence of various colors in the dark are called luminous materials. Humans have a long history of using luminous materials. For example, they are used on the dial of a watch to make a luminous watch.
Luminous materials are divided into two types: self-luminous and light-storing. The basic component of self-luminous luminous materials is radioactive materials, which do not need to absorb energy from the outside and can continuously emit light, not only at night but also during the day. Precisely because it contains radioactive substances, its use is subject to greater restrictions, and disposal after disposal is also a major problem. Photostorage luminous materials rarely contain radioactive substances and have no restrictions on use. However, they must absorb external light energy to emit light, and they must store enough light energy to ensure that they always emit light. Another drawback of phosphorescent luminous materials is insufficient brightness. For example, zinc sulfide has been used as an afterglow phosphor in the past, but the luminescence time was too short and the brightness was not enough. So later, a radioactive isotope, Ju-147, was mixed. The luminous effect was ideal, but the radioactive isotope intervened. Does not meet the requirements of environmental protection.
Although there are pollution-free luminous materials now, the patent rights belong to Japan and the cost is very high, so the cheap luminous accessories on the market should all belong to the former.