My life, like many of yours, is jam-packed to the nth degree, so I like to take shortcuts wherever possible. Yet, despite the fact that most bagged lettuce and veggies proudly sport "pre-washed" status on their packaging, a little voice in the back of my mind always nagged me to give 'em an extra rinse. It turns out that my lazy instinct is potentially the smarter one, at least in the professional opinions of many food safety specialists.
The rationale is actually pretty sound. For example, if you take a pre-washed, perfectly clean bag of roughage and expose it to a bacteria-laced sink, cutting board or colander, you're totally wrecking the goods and setting yourself up for a king-sized stomachache. Also, even if the bagged lettuce or broccoli florets are contaminated with something as vicious as salmonella, your quick rinse isn't going to fix matters. In fact, nothing short of cooking will eradicate those heavy-duty germs [source: Charles].
If you're still not willing to trust Big Produce with washing duty, it's easy to take care of lettuce handling safely. Simply take steps to avoid cross-contamination (like cleaning the sink first if you just used it to rinse meat), then rinse the lettuce and store in a refrigerator at less than 40 F (4 C) to inhibit or prevent bacteria growth [source: CBS New York].