There are basically five parts to a Bic Pen. The cap, barrel, and ink tube are made of plastic, while the ballpoint and tip are made of metals.
The barrel of the pen is made of polystyrene, a cheap, mass produced plastic. The production of polystyrene releases chlorofluorocarbons (Schwarz, Leisewitz 1999) into the environment- gases that have roughly 1200 times the greenhouse effects of carbon dioxide. In addition to being cheap, polystyrene also has the benefit of being clear so a user can see how much ink remains in the pen.
The ink tube and cap are made of polypropylene, a slightly more environmentally friendly plastic that can be recycled. It is chosen for its durability and impact resistance. While Polystyrene is prone to brittle cracking, the PP cap can prevent it from breaking when dropped or impacted. LyondellBassell Industries in the Netherlands is the worlds biggest producer of Polypropylene (Plastics News 2009).
The tip is made of brass, an alloy of copper and zinc. Copper is one of the worlds most mined minerals and its extraction is known for causing great ecological stress. Open pit mining techniques are popular and can affect water tables and leach acidic mining chemicals into aquifers.