Duracell takes environmental concerns seriously and has made significant efforts to minimize harmful substances in its batteries. In fact, the company has phased out the use of mercury in most of its alkaline batteries, adhering to strict safety and environmental regulations. The most commonly used Duracell alkaline batteries, such as AA and AAA, do not contain mercury. However, it is important to note that some older battery technologies, like certain types of button cell batteries, may still contain small amounts of mercury. Duracell encourages proper disposal of batteries to ensure safety and ecological responsibility. For more detailed information, including specifics regarding various battery types, it may be helpful to refer to the current section of Duracell's website that addresses safety and environmental guidelines.