Barry,

I can't offer much other than letting you know how we handle it in our Chemistry department.

From the Student/Instructor/TA ratio my guidelines is:

1-12 students = 1 Instructor

>12 students = 1 Instructor + 1 TA/lab assistant

Cap at 24 (or lab capacity if smaller than 24) BUT there has to be a TA/lab assistant for sections over 12 registered students.

We have these caps/guidelines in place because of safety as well as the learning environment. A single instructor to 24 students, especially in a lower level course with inexperienced students, is almost (in my opinion) asking for disaster to strike.

We also keep check sheets for safety, lab accidents and close calls. These get tallied up at the end of the semester and shows nicely how larger classes tend toward more safety incidents. Each section records the number of enrolled students, course level and goes on to separate safety issues such as PPE use, spills, breaks, fire, physical exposures and medical as well. Any accident that requires medical intervention also gets documented and an incident report and follow up.

Micro labs use more than just Bunsen burners of course. There are the various stains, solvents for decolorizing which tend to be flammable, various media which have additives and indicators. If you're working with broths there is always the increased chance of spills as you increase the number of bodies trying to get to the incubators and/or coolers, and don't forget the disinfectants. Though you are working with BSL/RG1 organisms, there are other hazards…I see a whole host of reasons not to increase the number of students.

I have not found any "regulations" or legal documents that state specifics, they may be out there but I doubt it.

Just my humble opinion,

Mel

Mel Charlton-Smith

Chemical Hygiene Officer, Lab Coordinator, Lecturer

BS-CHO program

Department of Chemistry

WV Wesleyan College

Buckhannon, WV 26201

charltonsmith**At_Symbol_Here**wvwc.edu

304-473-8355

From: DCHAS-L Discussion List [mailto:dchas-l**At_Symbol_Here**MED.CORNELL..EDU] On Behalf Of Ferm, Barret
Sent: Wednesday, September 26, 2012 5:37 PM
To: DCHAS-L**At_Symbol_Here**MED.CORNELL.EDU
Subject: [DCHAS-L] Microbiology lab safety: faculty:student ratio

Dear Lab Safety Professionals,

I have been asked if there are well established guidelines (read: defensible) for limits of student: instructor ratios, or other specific data, reasoning, etc., regarding introductory microbiology laboratory (where only BSL/RG 1 organisms are used).
Currently, the micro labs are capped at 12 students. There is one instructor (no TA), and every student works with his/her own Bunsen burner.. The lab has seats for 24 students (the lab is multi-purpose). An administrator wants to double class size to 24, but the biology faculty feel doing so will compromise the learning environment, quite possible from a safety perspective.
Are there any persuasive arguments against a 24:1 student:instructor ratio in microbiology in particular? They are dealing with an administrator, so the only picture said administrator can see thus far is 12 micro students occupying a space that can hold 24 general biology students. The adage that fewer is better is non-specific. Please advise if you know of guidelines pertaining to micro or similar settings. Thanks!

Barry Ferm

"Kindness in words creates confidence. Kindness in thinking creates profoundness. Kindness in giving creates love." - Lao Tzu