At some point in the late 90s, I suggested to my principal that a chemical inventory should be completed and many chemicals should be disposed of. I had inherited a large amount of chemicals when I took the chemistry teacher position (the only one in the district). Many of them were known carcinogens that I did not feel comfortable using with my students. Some were in extraordinarily large quantities that I knew I could never use up. There were bottles that had clearly passed their shelf-life because the crystals would not separate or they were no longer in a solid state, but a gooey mess instead. And, yes, the chemicals were stored alphabetically rather than by families. I estimated the time required and my principal agreed to compensate my work over the summer. Too much time has passed for me to be certain, but I believe I documented about 60 hours. (I know that I had done some upfront work during the regular school year that I did not bill for since it was before I realized how much time it would require.) I used the Flinn catalog to help me determine the storage pattern. I also used their guide to determine how to dispose of unwanted chemicals. As I worked, I entered every chemical that was reshelfed in an excel file. I included the name, formula, the mass or volume, Molarity when appropriate and also the location where it would be stored. I printed the document and kept it in a folder in the prep lab along with the MSDS files. I recorded the amount of each chemical used or replaced on the printout and once or twice per year, I made adjustments in the excel file. I also documented the details related to the chemicals that I could not dispose of safely myself in the lab and boxed them for the district's maintenance department to deliver them to a disposal site.
With the relatively new Globally Harmonized System of Classification and Labeling of Chemicals (GHS) in place, I had been updating my storage methods and labelling the last few years. I soon realized that I needed time outside of my regular teaching schedule to complete another inventory and disposal. I felt that because my teaching strategies had changed drastically since the last inventory and disposal, there were many chemicals that I no longer had a use for. So some chemicals were disposed of just because I had excess quantities, but there were also some that had passed their shelf-life. This time around, I convinced my principal to purchase software from Flinn, ChemInventory, along with labels that I could use to ensure all of the data required by GHS was on every container.
The Flinn website sums up their software with these sentences, "Flinn’s Online Chemventory™ Inventory Management System is a cloud-based lab management system that allows multiple users on multiple devices from multiple locations! Available as a 1-Year, 3-Year or 5-Year license." My district purchased the 5 year license for $349. The one year price is $99. I found the tool to be easy to use. I uploaded chemicals, entered an estimated quantity we were starting with and added a minimum quantity so that I could easily generate a report of all chemicals that needed to be reordered at the end of the school year. I helped some of the other science instructors to upload their chemicals. The program asked for the specific storage location. Several of our staff liked that they could easily search the system to see if a chemical was available in someone elses storage area. Many of our containers had been handwritten, especialy if the contents were a solution. It was simple to tag the item in the Chemventory system and then print off labels with appropriate safety symbols and details expected by the GHS. I still keep a print copy of the inventory in the prep lab. We write notes if we use or add a quantify. When we have time, we update the online platform.
It is very simple to invite other science teachers in your district by email to log themselves into the program. They can upload their own chemicals and print their own labels with the right credentials. You can also invite administrators or others to log into the system without allowing them to modify anything. I appreciated the ease of using the platform, the ability to easily print labels including the safety symbols, allowing many teachers to access and be able to search what is available in different classrooms. I am confident that the program will be worth the price if our science department follows through with continually updating the amounts used and added.
As I did with the first inventory, I disposed of many chemicals with the help of the Flinn catalog. When the inventory in our district was complete, I provided a hard copy to the main office in case the fire marshal stops in to ask for it. When all was done, I had spent about 90 hours. This time around, I had to create a lot of labels to meet the newer standards and I also visited the science classrooms in the all the district facilities (except for the elementary schools).
This resource has been valuable to me, but it is not really the method you use that is important. The most important pieces of this are that you have the Safety Data Sheets (SDS) available and you are storing your chemicals and disposing of unwanted chemicals safely and to the standards of GHS. It is also important to have an inventory available for the local fire department.