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.

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...

Dry Scraping Causes Chemical Explosion

November 13, 2015
Office of Environment, Health, and Safety
What Happened?

A postdoctoral researcher was synthesizing potentially explosive material in a fume hood, following a well-established procedure published in a peer-reviewed journal. The researcher was transferring a residual amount of the synthesized material using a plastic spatula when the material exploded in his hands. The shattered glassware caused some minor cuts to the researcher’s hands.

Other group members helped the injured researcher wash the injuries and called campus police. He was taken to the hospital where he got treatment for the injuries, and he was released from...

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...

Chemical Explosion Causes Eye Injury

May 31, 2015

ANSI-approved safety glasses—and other personal protective equipment specified in the Standard Operating Procedures (SOPs)—are essential whenever working with hazardous materials. SOPs also indicate other precautions that must be followed to ensure safety, such as performing work with energetic or explosive materials behind a fume hood sash or blast shield.

What happened?

A graduate student researcher was working at a laboratory bench synthesizing approximately one gram of diazonium perchlorate crystals. The student was transferring synthesized perchlorate using a metal spatula...

Accidental Mixing of Bleach and Acid

October 31, 2009
Office of Environment, Health, and Safety
What Happened?

A researcher working in a laboratory glassware washing area thought she should refresh the bleach solution for soaking lab glassware. In an "inattentive moment" she added fresh bleach to what she thought was the bleach soaking tub; unfortunately the tub did not contain bleach but contained 5% hydrochloric acid. The acid solution (with bleach) immediately turned from clear to yellow. She quickly realized that bleach and acid should never be mixed because toxic chlorine gas can be created. She immediately had everyone leave the room; she considered calling 911, but since...

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...