You&#x27;ve missed the point: Growing bacterial colonies in a culture is inherently riskier than day-to-day contact with sick people.<p>I&#x27;ve worked in high-energy or high-risk systems nearly all of my career.  There is such a thing as managed risk.  The school didn&#x27;t tell the family that they couldn&#x27;t do the experiment.  Instead, they owned up to the fact that the school didn&#x27;t know how to manage this particular situation&#x27;s risks correctly, and instead deferred to someone who did.  That&#x27;s a totally rational and reasonable response.