Is tritium dangerous: a review of the radioactive keychain

Greetings, Muscovites!
If you have no prejudice about radiation - welcome.
I will talk about a keychain with an amazing wow effect.
So that there are no further questions on word formation of all kinds of forms of the word “keychain”

A package with a keychain arrived in record time - in 8 days:

The keychain was packed in a plastic bag. A package in a small cardboard box:

The seller indicates the size of the keychain:

My measurements do not slightly coincide with those indicated, the length of the keychain was 1.8 cm, instead of the declared 2 cm:

This keychain does not need batteries or sunlight, according to the seller, it will glow independently for 12 years. Other sellers write that 25 years.
Inside the keychain case is an ampoule with tritium. Tritium is a superheavy radioactive isotope of hydrogen. The ampoule with it is covered with a phosphor. As a result of the beta decay of tritium, the beta particles, falling on the phosphor, cause it to emit light. That is, it is the phosphor that shines, and not tritium.
Let's figure out how much reallythis keychain will glow. The half-life of tritium is 12.3 years. During this time, and its brightness should fall by about half. By the way, here's what Wikipedia thinks about this:
Tritium illumination, on the other hand, loses about half the brightness within 12 years from the date of manufacture (the half-life of tritium is ~ 12.5 years) and about 75% of the brightness after 25 years.
And there is the likelihood that the phosphor will burn out much earlier than all tritium decays.
I have a green glow keychain. There are key chains and other colors (the color of the glow depends on the phosphor). Unfortunately, the intensity of the glow of the trinkets of other colors is less. This is due to the fact that our vision is most susceptible to green shades.
The keychain emits a very soft light in the dark. But! Something cannot be highlighted for them. So if someone thinks that a keychain can be found, for example, a keyhole, then I will disappoint you. But finding something that this keychain is attached to is easy.
Let's move on to pictures with different lighting. Softbox Light:


Total darkness:

Total. If you are not paranoid, who, at the word radiation, immediately grabs his cap made of lead foil, and if you try not to think about the price, then the keychain cannot but be liked. Absolutely everyone will cause at least interest.
If you wish, you can watch the video version of the review:

It must be here