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.

Lesson Learned: Aerosol Exposure in BSL2 Lab Caused by Centrifuge Failure

February 26, 2026
Last November, a researcher in a BSL2 lab was centrifuging stocks of a Risk Group 2 biological agent when the centrifuge experienced a catastrophic failure. The researcher heard a loud pop in the middle of the cycle and went to open the lid. The researcher determined the aerosol tight rotor bucket had cracked and carried it to the tissue culture room across the lab, not realizing the conical tubes inside were also broken. Since the biological agent spilled has an aerosol transmissible route of exposure, personnel present in the lab during the incident were advised to seek assistance from Occupational Health.

Flooding Event and Improper Disposal of Glassware

March 6, 2025
Office of Environment, Health, and Safety
What happened?

Last month, severe flooding occurred in a campus building, leading to unexpected challenges in laboratory waste management.

A serious concern emerged when floodwater seeped into cardboard boxes, used for clean glass disposal, that did not have plastic liners. Without this essential barrier, the integrity of the boxes were compromised, rendering them unsafe for handling and disposal.

As a result, safety responders had to take extra precautions to safely transfer the broken glass and sharps to new disposal...

Corrosive Waste Spill

August 31, 2015
Office of Environment, Health, and Safety
What Happened?

A UC Berkeley researcher was working in a lab with a highly corrosive sulfuric acid and hydrogen peroxide (piranha) solution to clean the surface of a glass sample in a fume hood.

After completing the work, the researcher found the existing waste container to be greater than 75 percent full. Rather than add the recently used piranha solution to the already overfilled waste container, the researcher found an additional empty waste container and attempted to pour off some of the overfilled waste into the empty bottle.

During this attempt, some of the corrosive...

Skin Burns from Heating Glass Vessel

September 25, 2023
Office of Environment, Health, and Safety
What happened?

A researcher was heating a small volume (<30mL) of hexanes/ethyl acetate containing approximately one gram of an organic azide. The solution was placed in a capped, 40mL pyrex media storage bottle. Holding the bottle of the azide solution in their left hand, the researcher was heating it with a heat gun with their right hand behind a horizontal fume hood sash protecting their face and torso.

Fume Hood Sash Cracks due to Reaction Vessel Overpressurization

September 25, 2023
Office of Environment, Health, and Safety
What happened?

Using dry Dimethyl Sulfoxide (DMSO) as solvent, a reaction between an organic macrocycle and bromoethane was placed in a round bottom pressure vessel. The reaction was heated using armor aluminum beads in a stainless steel bowl sitting atop a hotplate. The setup was briefly left unattended inside a fume hood with the sash closed.

Without a means for temperature control, the hotplate generated excess heat, which in turn produced excess pressure. Overpressurization caused the round bottom vessel to shatter. Glass shards along with the aluminum heating beads...

Fall from Fixed Ladder with Grab Bars Results in Injury and Fine

October 24, 2018
Office of Environment, Health, and Safety
What happened?

A campus employee was holding onto the grab bars at the top of a fixed vertical ladder and was beginning to descend when one of the grab bars broke off, causing the employee to fall about 13 feet. The employee sustained significant injuries to several toes. The incident occurred on a roof mounted cooling tower.

What went right? Two employees were working together and a third was nearby and able to help, Emergency medical providers and UCPD were called and responded immediately. What should have been done differently? The ladder system should have been built to withstand...

Lessons Learned: Soldering Exposure

November 13, 2025
A researcher was soldering on an open bench for extended periods of time over two days. The work was quite small and included soldering many wires to connectors. The researcher was exposed to soldering fumes resulting in irritation to the respiratory system. Symptoms experienced included watery eyes, coughing, chest tightness and dry nose & throat.

Eye Exposure to Specular and Diffuse Reflections

October 17, 2016
Office of Environment, Health, and Safety
What happened?

A student conducting a physics experiment was briefly exposed to specular and diffuse reflections from a continuous wave 975 nm invisible laser beam while not wearing laser eye protection. The student was applying oil to an objective lens with a glass stick when it was noted that the laser was still on. The student was immediately referred to the optometry clinic and was promptly examined. No eye damage was found.

What went right?

The student immediately stopped work and alerted their professor as soon as...

Eye Exposure to Specular Reflection

July 31, 2015
Office of Environment, Health, and Safety
What happened?

A researcher was diagnosing a power loss from a Spectra Physics 3900 Ti-Sapphire (oscillator) that is pumped by a Spectra Physics Millennia eV DPSS laser. During this procedure, they noticed some leakage in the form of a slight green diffuse light being emitted from the end of the metal tube connecting the DPSS pump laser to the Ti-Sapphire laser. The researcher attempted to re-adjust the beam tube to eliminate the leakage to improve the beam tube alignment. As he touched the beam tube, it became dislodged from its mounting, striking the 532 nm laser beam as it fell, causing...

Laser Eye Exposure from a Specular Reflection

June 17, 2024
Office of Environment, Health, and Safety
What happened?

A researcher walking towards an optical table was exposed to a laser beam that reflected off a hex ball driver tool. Another researcher at a nearby bench was installing an optical component on a breadboard when the hex ball driver he was using inadvertently moved into an active beam path. The hex ball tool had a reflective surface.