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.

Eye Exposure to Specular Reflection

July 31, 2015
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...

Corrosive Waste Spill

August 31, 2015
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...

Exploding Cylinder in Garbage

July 31, 2007
What Happened?

On April 11, 2007, an employee of Campus Recycling and Refuse Services was alarmed when a suspected compressed gas cylinder ruptured in the rear hopper of a garbage truck. The employee was standing at the rear of the truck and had activated the blade that sweeps the garbage from the hopper into the body of the truck for further compaction. The pressurized gas cylinder was believed to be concealed inside a plastic trash bag. The sweeping action of the blade ruptured the cylinder and the residual contents sprayed into the employee’s face.

A cylinder in a garbage truck...

Discovery of an Old Container of Potentially Explosive Chemical

June 30, 2008
What Happened?

While working in a UC Berkeley laboratory, a graduate student discovered the presence of an old experimental set-up, which was labeled as containing a small amount of hydrazoic acid, in a shared cold room with no responsible contact person. This material is a potentially explosive chemical under certain circumstances, so the student referred the set-up to the Department Safety Coordinator (DSC). The DSC requested the assistance of EH&S who recommended that the set-up be disposed of by an explosives material contractor because very little was known about the source...

Improperly Vented Experiment Causes Explosion and Burns

June 30, 2008
What Happened?

A graduate student working in a UC Berkeley laboratory was performing a series of evaporation procedures outside of a fume hood using a general-purpose electric pump and a roto-evaporator that had no exhaust equipment. In an effort to make the solvent recovery more efficient, the student applied a vacuum to the condenser tower but quickly turned the pump off because the vacuum was too strong. By that time, the pump exhaust had already formed an explosive mixture of the acetone and ether vapors which ignited when the power shut-off switch was activated, resulting in...

Explosion of Concentrated Hydrofluoric Acid Waste Solution

June 30, 2008
What Happened?

A graduate student in a UC Berkeley laboratory discovered the aftermath of a chemical explosion 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 explosion. The hood, floor and walls near...

Exposure to Bromine During a Laboratory Refrigerator Clean-up

June 30, 2008
What Happened?

While performing a chemical inventory inside a laboratory refrigerator, a UC Berkeley graduate student observed the presence of condensate on the inside walls of the refrigerator. This student and two other graduate students proceeded to clean the refrigerator walls, assuming that the condensate was water. When one of the students noticed a bottle of 99% bromine had a small leak, clean-up was immediately stopped, a sign was posted on the door to keep away, and the Department Safety Coordinator (DSC) was notified of the accident. The DSC summoned EH&S clean-up...

Exposure to Poisonous Chemicals Due to Improper Storage and Unsafe Work Practices

June 30, 2008
What happened?

A graduate student working in a UC Berkeley laboratory needed a chemical from an overhead shelf. To reach the chemical, the student stood on tiptoe and leaned on the edge of a shelf. This pressure caused the shelf to shift and chemicals to fall. Among the bottles that fell were two that were covered with aluminum foil instead of the original screw-on caps. Those containers held strychnine powder and azure blue dye. The contents fell on the researcher, bench, and floor. The exposed researcher spent 15 minutes under a safety shower and then went to the Tang Center for...

Superconducting Magnet Explosion

July 31, 2008
What Happened?

A 9.4 Tesla superconducting magnet, used for mass spectroscopy in a campus laboratory recently suffered a catastrophic failure. The incident was apparently caused by over-pressurization and failure of the liquid helium (LHe) chamber. Although there were no injuries because the incident occurred during off-hours, the potential for significant injury due to the venting of LHe into the facility was present. There was also significant damage to equipment associated with the magnet.

A magnet achieves superconductivity (zero resistance to electrical current) when it is...

Vacuum Chamber Over-pressurization

Lessons Learned

Pressurized systems hold a great deal of energy. Over-pressurizing a chamber can cause adverse effects such as the view window rupturing. Care should be taken when returning these to atmosphere.

To prevent similar incidents, follow the recommended guidelines below:

Pressure relief valves and additional personal protective equipment (PPE) can be important safety measures in the event of a system failure. A SOP should be written for hazardous processes based on a hazard analysis.

For additional assistance, contact EH&S at...