I can't really say how safe it would be. Usual tests would apply. It was in a box of things I used many, many years ago. If I recall I used the gel with the dark amber filter in place as well, that's how I found it. You might try that or several layers of the gel. If you want PM me your address and I'll drop it in the mail. BTW it's just under 4 1/2 inches in diameter so might want to double check the size first.