10. Purchasing Controls: Stopping Problems Before They Start

Most chemical inventory problems are easier to prevent at the purchasing stage than to fix later in storage. A few structural controls go a long way:

• Route all chemical purchases through a single approver (department chair or Chemical Hygiene Officer) rather than allowing ad-hoc ordering by any staff member.

• Check existing inventory before ordering. A shocking share of duplicate purchasing exists simply because no one checked what was already on the shelf.

• Buy only what a specific unit or year’s curriculum will use, particularly for peroxide-forming and other time-sensitive chemicals.

• Decline unsolicited donations without vetting them first. Retiring teachers’ personal collections and donations from local businesses or colleges are a leading source of unknowns, banned substances, and duplicate stock.

• Log every incoming chemical into the inventory the day it arrives, not at the next scheduled review.

Checklist: Receiving New Chemicals

• Purchase was pre-approved through the designated approver

• Inventory checked beforehand to confirm the chemical wasn’t already on hand

• Container inspected for damage or leaks upon arrival

• SDS obtained and filed before the chemical is placed into use

• Chemical logged into the digital inventory with CAS number, quantity, and hazard class

• Peroxide-forming or other time-sensitive chemicals dated immediately

• Chemical stored in its correct compatibility group before end of day

⚠️ Common Mistake: A new chemical arrives during a busy week, gets set on a counter “to deal with later,” and is never formally logged. Months later, it’s an unlabeled mystery to whoever finds it next.

Internal link opportunity: Building a Chemical Purchasing Approval Process for Science Departments.