Incubators (Contaminated vs Non contaminated)

Hello,



I have a question regarding incubators. Where I work, we segregate our so called contaminated work (intentionaly contaminated media/agar plates) and non contaminated work (product analysis wich are usualy exempt of bacteria).



Is there any pertinance in doing so? If not...are there any controls (periodic air sampling) that are needed to be done in order to eliminate the possible contamination factor (or to prove that it is not the incubator who contaminated my plate and gave me a false result) IF we put all our work (contaminated and non contaminated) in a single incubator?



Thank you in advance!