a biohazard centrifuge having an improved air cooling arrangement , wherein a cooling air stream is directed onto and around the rotor chamber of the centrifuge without introducing cooling air thereinto . this results in cooling air being separated from the spinning rotor and reduces the possibility of contamination of the cooling air stream from a leaking sample container . additionally , further protection to laboratory personnel is afforded by a sealed rotor assembly chamber , and by providing rotor assembly specimen containers or carriers having lids which are easily attached and removed , requiring a simple partial twist to lock the lids into place .