Coffee and E. coli

Out of all the equipment used in chemistry and biochemistry, one piece of machinery can be counted upon to be present in every lab, nearly without fail. This machinery is of course a standard coffee maker, which is used for a daily minimum of two dozen cups of coffee in this laboratory setting. This usage creates waste, including empty coffee containers, usually of the plastic variety. Here, we show the use of different coffee containers as a waste bucket for pipette tips, centrifuge tubes, or other lab materials.

Standard 3-lb and 1.5-lb Folgers coffee containers were found to be very effective, (Figure 1) with the 3-lb containers being of sufficient height to hold long serological pipettes. The 1.5-lb containers, while very useful, have the same base and lower height, making the disposal of top-heavy objects problematic.

Figure 1 - 3-lb coffee container used for waste

These Folgers containers also are made of a recyclable plastic, ensuring the easy disposal of the disposal apparatus when the disposal of other disposable objects is complete. This composition also allows for quick and effective cleaning with organic solvents and bleach.

Classic Roast coffee containers of a medium-roast variety were investigated, but results give no indication that dark roast or medium-dark roast containers would have variance in performance. In the context of a research laboratory, mild-roast containers were found to be completely and totally irrelevant.

Metal coffee containers of the Sam's Club variety were investigated in this report, but found to be ineffective due to their propensity to corrode. This is due to a number of liquids being present in the waste container, either because of direct user input, or leakage of other waste materials. When cleaned with bleach (as is protocol in a biochemistry laboratory) the corrosion and remaining biological material react, creating hazardous fumes as well as an unpleasant foam. To avoid this, a plastic bag may be placed inside the container. Their positive qualities, however, include a heavier weight which allows for the disposal of larger serological pipettes without the canister tipping over, as well as a satisfying *ping* sound when disposing of smaller pipette tips.

In conclusion, we can safely recommend the usage of plastic coffee containers as disposal units for pipette tips and other waste materials.