There are several different types of mercury-containing light bulbs available to consumers. Since the type of mercury (elemental mercury) in mercury-containing light bulbs is toxic, consumers should handle certain light bulbs with care.

Many light bulbs on the market contain elemental mercury. All HID (high-intensity discharge) light bulbs including metal halide and high-pressure sodium light bulbs contain certain levels of mercury. 250-watt metal halide and high-pressure sodium light bulbs contain 38 mg and 15 mg of mercury respectively. Even fluorescent light bulbs contain around 5 mg of elemental mercury regardless of wattage.

Exposure to elemental mercury in even small amounts can negatively affect a person's health. According to the Environmental Protection Agency (EPA), some symptoms of mild exposure to mercury include, but are not limited to insomnia, headache, mood changes, muscle atrophy and irritability.

Overexposure to the elemental mercury in certain types of light bulbs can be fatal. Extended exposure to mercury can result in respiratory or kidney failure. Death can also be a side effect of overexposure to elemental mercury. People that have been exposed to any level of mercury should seek medical help immediately.

Severity of symptoms associated with mercury exposure depend on several factors. Some factors that determine the severity of side effects from mercury exposure include a person's overall health, duration of exposure, route of exposure like ingestion or inhalation and the age of the person that has been exposed. Fetuses have the greatest chance of experiencing negative side effects when exposed to elemental mercury.

A broken mercury-containing light bulb poses obvious health risks to people in close proximity. If a mercury-containing light bulbs breaks, everyone should exit the room for about 20 minutes and give the elemental mercury a chance to dispel throughout the room. Fresh air, if possible, should be introduced by opening a window.