Peroxide-Forming Chemicals

Disclaimer: The requirements outlined in this category serve as general institutional guidance. Because chemical properties and reactivity vary, Principal Investigators and lab personnel must review the manufacturer’s Safety Data Sheet (SDS) for chemical-specific handling, containment, and protective equipment protocols that may supersede these general rules. 

Testing Requirements 

Peroxide forming chemicals, depending on the class of the chemical, must be tested on a regular basis. Below are the Testing Requirements based on the class of Peroxide Forming Chemical:

Testing allows labs to safely extend the shelf life of Class A and B chemicals, but only if the results are actively logged on the bottle.

• Class A Frequencies: Must be tested every 3 months after opening. Additionally, best practice dictates testing Class A liquids immediately before every single use.
• Class B Frequencies: Must be tested every 6 months after opening, and always immediately prior to any distillation, rotary evaporation, or concentration process.
• Class C Exception: Do not test Class C chemicals. Most campus EHS policies explicitly forbid routine testing of Class C liquids because the mechanical motion of testing can trigger the very polymerization explosion you are trying to prevent. They should be managed strictly by the clock and disposed of when expired.

Action Thresholds Based on Test Results

When labs test using semi-quantitative peroxide test strips, your policy needs explicit ppm (parts per million) action thresholds:

• Less than 25 ppm: Considered safe for use. Material can be retained, and the expiration date can be extended (usually by another 3 or 6 months depending on class).
• 25 to 99 ppm: Safe for general use, but strictly forbidden from being concentrated or distilled. Disposal should be scheduled soon.
• 100 ppm or greater: Immediate Hazard. The chemical must not be used. It must be locked down and flagged for hazardous waste disposal.

The "Never Touch" Protocol (Crucial for Campus Safety)

Before any chemical test is conducted, a visual inspection is mandatory. Your campus rules should explicitly state that if a bottle shows any of the following signs, lab personnel must not touch, move, or open the container:

• Visible crystal formations (often looking like salt, ice, or white powder around the cap threads or rim).
• Cloudiness, liquid discoloration, or a distinct viscous/waxy layer at the bottom.
• Wisp-like structures suspended floating in the liquid.

In these cases, unscrewing the cap provides the friction necessary to detonate the bottle. The lab must immediately isolate the area and contact EHS for specialized, stable disposal.

Storage Requirements

Varies between chemicals, please consult the specific SDS for peroxide-forming chemicals.

Incompatible Chemicals

Strong oxidizing agents, strong acids, air/oxygen (over time), and halogens. Examples include Nitric acid, Sulfuric acid, Hydrogen peroxide, Oxygen, and Chlorine gas.

PPE Required

• Chemical splash goggles
• Lab coat
• Some Peroxide Forming chemicals may also require a face shield and/or a fume hood for operation