Lessons Learned

Reports on incidents that involve injury, exposure (real or potential), or significant damage property. Lessons Learned detail what happened and how similar incidents can be avoided in the future.

Biological Safety

Providing support, in the form of risk assessment, review, consultation and training, for research at UC Berkeley that involves the use of recombinant DNA, biohazardous materials and biological toxins.

illustration of a biohazard symbolHow Do I: collapse all...

Lesson Learned: Overpressurization of Incompatible Waste

September 25, 2026
What Happened

An incident occurred when incompatible chemical wastes were combined in a plastic waste container, leading to overpressurization and a subsequent chemical spray.

The lab’s standard practice was to consolidate various waste streams into a single container labeled "halogenated waste," rather than segregating them by chemical compatibility (e.g., separating aqueous and organic waste). In this instance, the researcher also kept sodium bicarbonate in the waste container to neutralize acid waste.

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Fall from Fixed Ladder with Grab Bars Results in Injury and Fine (October 2018)

Lessons Learned

In addition to the lessons described in the What Should Have Been Done Differently section, major takeaways are to guard against complacency and to always consider the Integrated Safety Management (ISM) process, even for routine tasks.

For additional assistance, contact EH&S at ehs@berkeley.edu or (510) 642-3073, Lessons Learned date: 7.2018

Nitric Acid Waste Over-pressurization Event

July 3, 2018
Office of Environment, Health, and Safety
What happened?

A graduate student researcher was consolidating aqueous nitric acid solutions into a 4-L bottle marked as hazardous waste. The bottle was stored inside a fume hood along with other waste bottles, organic reagent bottles, a hotplate and an oil bath. The fume hood sash was left open when all researchers left at the end of the day.

Several hours later, a custodian entered the lab and saw broken glass and brown liquid on the floor. It appears that the nitric acid waste was stored in a bottle that contained residual organic compounds, the combination of which generated...

Peroxide Explosion Injures Campus Researcher

November 30, 2006
Office of Environment, Health, and Safety
What Happened?

An undergraduate student researcher was working at the laboratory bench when the apparatus she was using exploded, sending glass fragments into her face and upper torso. The researcher was using a rotary evaporator (rotovap) to remove organic solvents from an azobenzene precipitate. She adjusted the bottom flask which then exploded sending glass towards her face, hitting her safety goggles and forehead. Lab personnel helped her to the safety shower and called 911. She was taken by ambulance to the hospital where she received stitches above her eyes and other treatment...

Overpressurization of Concentrated Hydrofluoric Acid Waste Solution

June 30, 2008
Office of Environment, Health, and Safety
What Happened?

A graduate student in a UC Berkeley laboratory discovered the aftermath of a chemical waste overpressurization upon arrival at the laboratory he shares with other graduate students. The extensive contamination was caused by the explosive rupture of a plastic bottle of liquid waste kept inside the hood. According to the container label, one of the components inside the ruptured bottle was hydrofluoric acid. The investigation revealed that an incompatible material may have been poured into the same container causing the reaction and resulting overpressurization. The hood...

Workplace Safety

California state regulations require every employer to establish, implement and maintain an effective Injury & Illness Prevention Program (IIPP). In August 2017, the University adopted a campuswide Workplace Safety Program that serves as the University’s central IIPP for creating a safe and healthful work environment. Having one program for the whole University helps to improve access, consistency, and usability across all departments. EH&S is the responsible department for overseeing the campuswide Workplace Safety Program. The campus Workplace Safety Program is based on the Injury...

Lessons Learned: β-Mercaptoethanol (BME) Spill

June 30, 2026
What Happened

β-mercaptoethanol (BME) is a hazardous substance characterized by its acute toxicity, corrosivity, and reproductive risks. Additionally, its thiol group gives the compound a distinct, pungent odor.

A researcher was handling a bottle of BME when it fell and spilled approximately half its contents. This resulted in the researcher’s pants being saturated with the chemical, as they were not wearing a lab coat. The spill also impacted the surrounding floor and laboratory surfaces, resulting in the strong odor, similar to...

Employee Receives Electrical Shock

March 31, 2004
Office of Environment, Health, and Safety
What Happened?

A university employee was changing ballasts above a drop ceiling in a department reception area. The employee received an electrical shock from a 277volt circuit and was knocked off a step stool that she had placed on top of the reception desk. She fell from a height of 46.5 inches, but received only minor injuries and returned to work the following day.

What was the cause? The power source was not locked and tagged out. Instead, the light switch was turned off. The ladder to be used was too large to work from behind the reception desk, so a...

Injury Caused by High Voltage Capacitor Discharge

May 31, 2005
Office of Environment, Health, and Safety
What Happened?

A campus employee working in an electronics shop was repairing a power supply unit. The cooling fan had not been working properly, causing the unit to overheat. The employee replaced the defective cooling fan and then reached into the open top of the power supply unit to check the airflow from the replacement fan. The employee either made contact with a charged capacitor or was close enough (within 1/4") to allow electricity to arc to his hand causing an electric shock that entered his left hand and exited through his right hand.

Immediately after the...