In general, tissue culture waste, should be considered potentially infectious waste.

Autoclaving
Waste such as flasks, plates, gloves, and containers, should be placed in a standard autoclave bag, properly labeled, and autoclaved using liquid setting.

Waste such as Pasture pipettes, sharps or other material which could present a hazard to those who will subsequently handle it, must be placed in a suitable waste container and clearly labeled.

Chemical treatment
Aspirator bottles or suction flasks used for collecting media waste should be filled with 1/10th volume of household bleach before use. Never let the waste collection bottle overflow.

If waste contains dangerous materials that can't be autoclaved, it should be treated with a 1:10 dilution of household bleach for at least 12 hours.

For more information, visit http://www.niehs.nih.gov/odhsb/.