Environmental Health & Safety

Lessons Learned

A sampling of recent incidents and "Lessons Learned".

Description: Laboratory Fire

A researcher placed a pan of paraffin wax on a hot plate to melt and left it unattended for a short period of time, during which the wax had bubbled over onto the hot plate and caught fire.

Resolution: The researcher used a fire extinguisher to put out the fire, but the hot plate, other equipment on the bench, and all the materials on the shelf above were damaged. The fire department responded and verified that the fire was completely out before turning the lab back over to Yale. Facilities had an electrician inspect all wiring and outlets in the affected area, and ServiceMaster was contracted to clean the extensive extinguisher debris the following day.

Lesson Learned: Never leave items on hot plates unattended, even for short periods of time.

Description: UV light exposure

A graduate student operating a transilluminator multiple times over a one hour period, suffered skin reddening and temporary eye injury from UV exposure to her face and eyes. This student was wearing the appropriate face shield but the shield on the box itself was not in use.

Resolution: The UV transilluminator and face shields were initially taken out of service until they could be further evaluated by EHS. A physical inspection of the face shields available in the lab confirmed that none were cracked or broken, but several were physically filmed over and difficult to see through. The transilluminator shield was re-attached to the box and new polycarbonate face shields were ordered. UV measurements were taken with the transilluminator at maximum power to confirm that the transilluminator shield and face shields provided a high degree of protection against UV exposure (>99% reductions).

Lesson Learned: Since even at several feet away, unshielded exposure from a UV transilluminator can be many times greater than the summer midday sun, it is critical that users keep the light box shield in place except when actively handling a gel, and that a face shield, safety glasses, gloves, and fully buttoned lab coast be worn whenever working with this device. Safety posters are being revised and reposted at all transilluminators.

Description: Broken mercury thermometer

An undergraduate student broke a mercury thermometer in her dorm room, spilling the mercury. This thermometer had been brought to her dorm room from home.

Resolution: EHS cleaned up mercury and broken glass and took air readings to confirm that mercury levels in the room were below all applicable limits. The broken glass and all residual spill material was double bagged and collected as hazardous waste.

Lesson Learned: Mercury thermometers should never be brought onto campus from home and are not allowed in any non-laboratory area, including dorm rooms. Most mercury thermometers used in laboratories on campus have been replaced with thermometers that do not contain mercury.

Description: Chemical permeation through glove

A researcher was wearing thin nitrile gloves and working with dimethylforma-mide. She realized that some DMF had spilled onto her gloves, but continued working and did not remove her gloves until she finished more than an hour later. After removing her gloves she noticed wrinkling and numbness of her fingers, washed her hands with soap and water, and went to Yale Health for evaluation.

Resolution: Yale Health contacted EHS, who sent over an MSDS and information on DMF. Researcher was treated and released. EHS determined that DMF will readily penetrate nitrile gloves, and provided a sample pair of butyl gloves to the lab to use with this chemical.

Lesson Learned: Thin exam style gloves offer limited protection from chemical exposure, and should always be removed after direct contact with chemicals. There is no one glove material that is good for all chemicals, so researchers should select the best glove using a glove selection chart. A glove selection chart was provided to the laboratory for their use.

Description: Needlestick

A researcher was injecting a chemotherapy agent into a mouse and accidentally stuck himself when removing the needle from the syringe.

Resolution: The researcher immediately removed his gloves, squeezed the small wound and washed his hands with soap and water for several minutes. He contacted EHS and went to Yale Health Acute Care for follow-up.

Lesson Learned: This incident demonstrates the hazards of recapping or manually manipulating sharps. Always use mechanical devices when directly handling sharps.

Description: Possible exposure to hydrofluoric acid

A researcher working with concentrated acids, including hydrofluoric acid (HF), noticed a small red mark on her wrist after removing her gloves. Because she had been working with HF, she applied calcium gluconate gel and went to the Employee Health Office (EHO) at Yale Health for evaluation.

Resolution: Employee Health sent her to Acute Care, who had her transported to YNHH. Doctors in the Emergency Room evaluated her wrist and determined that the mark was not caused by HF. EHS was contacted by EHO, and immediately visited the laboratory and verified that no chemical spill occurred.

Lesson Learned: If chemical burn is suspected, immediately rinse area and contact Acute Care 432-0123 and Yale EHS 785-3555. Never work alone with concentrated acids. Ensure that all required personal protective equipment is properly sized and available before beginning work with hazardous chemicals.

Description: Broken bottle of corrosive liquid

A researcher was placing a 4L bottle of hydrochloric acid into the corrosive cabinet beneath the fume hood when it bumped another bottle and broke. EHS was contacted for assistance in cleaning up this large spill, which luckily was contained inside the tray in the cabinet.

Resolution: EHS arrived and neutralized the spill, absorbed the liquid, and cleaned the corrosive cabinet base.

Lesson Learned: Corrosive liquids should be purchased in safety coated glass containers or plastic bottles. These are all available through Sciquest. Safety coated containers are designed to prevent liquid from spilling because they will shatter, but not break, if dropped or bumped.