Coincidentally, the world learned this year that India has nuclear weapons. The good properties of beryllium are noted above. One bad property is that the metal is brittle. Small particles, which can be inhaled, can chip off fairly easily. This makes beryllium a greater exposure hazard than other toxic metals.
Beryllium is very toxic.
OSHA's PEL for beryllium is the same limit the Atomic Energy Commission established for the metal back in 1949. Incidence rates among employees who machine beryllium rise as high as 10 to 14 percent. The latency period for CBD is generally 10 to 15 years, but it may take as long as 30 years from time of exposure to development of disease. Some people also experience sensitivities to very small amounts of beryllium. Don't be surprised if a debate heats up over whether any exposure to the material is safe.