DCHAS-L Archives · Post dated August 26, 2025
From: Bruce A. Hart <000018c2c7fcba23-dmarc-request**At_Symbol_Here**LISTS.PRINCETON.EDU>
Subject: Re: [DCHAS-L] Optimal Number of Students per TA/Instructor in General Chemistry Labs
Date: Aug 26, 2025 14:56 UTC
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**Princeton.EDU>
In-Reply-To: Re: [DCHAS-L] Optimal Number of Students per TA/Instructor in General Chemistry Labs
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--- For more information about the DCHAS-L e-mail list, contact the Divisional membership chair at membership**At_Symbol_Here**dchas.orgHello all,
We have had an explosion in the number of freshmen who are taking general chemistry this term, but funding has limited the number of TAs and instructors we have per lab room. The way the department has had to deal with this is to increase the number of students from 30 to 38 per section (limited by the Fire Marshall’s maximum occupancy of the rooms). They work in groups of 3 (not ideal at all). We have adjoining labs, so our shortage of instructors has been solved by having an instructor supervise two sections being held concurrently in a set of those labs. There is one TA per section.
In the past we have had 30 students (10 groups) supervised by a dedicated instructor (not working concurrent sections) and a TA, so about 15 students per person supervising. Now we can have as many as 38 students (13 groups) being supervised by one person at times, as the instructor moves between sections. I feel this is not safe.
What do people think is a safe ratio of supervising people to students (or student groups)?
Thanks,
Patricia Leach
Lab Manager
Department of Chemistry & Biochemistry
SLC 3.513
Office: 972-883-6583
Cell: 469-891-6426
