Brake Fluid:

WARNING: This page is about a different car, the 2007 BMW 550i, 2006 BMW 550i, 2005 BMW 545i, and 2004 BMW 545i. However, it is still accessible from the selected car via links, so may be relevant.

Replace brake fluid at least every two years.
Never re-use drained brake fluid.
Always use BMW-approved brake fluid.
Always dispose of brake fluid in approved receptacles.
Do not allow brake fluid to drain into drain pipes, into the outside environment or into unsuitable facilities. This would create the risk of groundwater contamination since brake fluid is classed as a fluid that is hazardous to water.
Do not allow brake fluid to come into contact with paintwork as this will destroy the paint.
Brake fluid must not be allowed to remain on bare skin too long in order to avoid skin problems. Wash skin coated with brake fluid with water and soap.
If brake fluid makes contact with eyes, immediately flush with large quantity of clean water and visit eye doctor.