An academic department turned over two green laser presenters labeled “Class 2″ to the Homewood Laser Safety Advocate for evaluation because one seemed “too bright.” Normally, a Class 2 laser presentation pointer should put out no more than 1 milliwatt of energy.
Both presenters were found to be putting out more than 10 times the allowable amount of energy, including energy in the invisible infrared range, which is more dangerous. (Green laser pointers are actually infrared lasers that use special optics to generate green light from the IR.) The Laser Safety Advocate tested several additional pointers from that department, finding them all in conformance with their markings. The overpowered pointers were disposed.
The overpowered pointers were actually hazardous Class 3B lasers which should not be used in an uncontrolled lecture or presentation setting. Homewood limits the power of laser pointers to Class 2; testing has shown that brighter pointers are not necessary in any lecture hall on campus. The class of a laser device is stamped on a small yellow or white sticker on the product.
These were name-brand laser pointers purchased from nonstandard sources (e.g., online auction sites); we are as yet unsure whether they were genuine branded products that are off-specification or if they were counterfeit. Please buy all laser pointers from standard JHU-approved sources such as Office Depot; unusual distribution channels are more likely to sell counterfeit or otherwise out-of-specification products. A sample of the sample laser presenter purchased from a JHU-preferred vendor measured within normal safe tolerances.
In 2013, the National Institute of Standards and Technology (NIST) found that 90% of green laser pointers and 44% of red laser pointers were out of compliance with federal safety regulations and their markings.
If you have a laser pointer that seems too bright, especially if it is green, contact the Homewood Laser Safety Advocate, Niel Leon, email@example.com. He can test your laser pointer and return it to you if it is safe to use (or help you find a source for a safe one if it’s not).
Recently, a researcher in MD Hall purchased two inexpensive “pointing lasers” over the Internet to use in an experiment. Fortunately, before starting work with the lasers, the researcher consulted with the Laser Safety Advocate—who determined that the lasers were actually dangerous 1-watt infrared Class 4 lasers, and a serious threat to anyone in the room if they were used without controls. With a little 3-D printer magic, the LSA re-engineered the experimental apparatus so that the system was a safer Class 1, not even needing protective laser goggles. Read about the case in Class 4 pointing lasers.
In the lab, we often collaborate with others in the lab or with outside researchers. It is essential that lab protocols be communicated consistently and in language everyone understands. Learn about a close call that occurred when a JHU researcher misunderstood an outside collaborator’s protocol in CCall miscommunication MD.
A researcher finished flame-sealing an ampoule in a chemical fume hood, turning off the torch used and setting it down. While the researcher was storing the ampoule, the hot torch tip ignited a number of lab wipes and rubber stoppers that had been left in the hood, and the cotton insulation on a nearby solvent still containing 1-2L of highly flammable tetrahydrofuran (THF) also ignited.
Learn more about this incident, including lessons learned at Incident Fire NCB Jun2015
During a lab move, a chemical container was moved to the wrong lab, where it remained for years. While the container read “Ethyl Alcohol” on the side, it actually contained chemical waste. Several years later, a student filled spray bottles with the contents of the container, and the lab used them for about a week to sanitize biological safety cabinets, equipment, hands, etc. Several researchers were exposed to the contents. Fortunately, analysis showed that the contents were water and a common solvent, and exposures were minimal.
Find out Lessons Learned and other information about this incident at Incident chemical exposure Croft Oct2014.
While performing experiments in a large water tank, a researcher placed an incandescent spotlight in front of a 2-inch thick Plexiglas observation window. During the experiments, the lamp slipped and came to rest against the window surface. The window melted one-third of the way through, compromising its mechanical integrity.
Learn more about this incident in Incident tank damage Krieger May2014.
A pair of undergraduates in a chemistry class loaded a pressure vessel (a “Parr bomb”) with reactants and placed the vessel in a furnace, leaving the reaction to run for the night.
Several hours later, during an evening class in the same lab, an unanticipated reaction occurred in the vessel. This raised the pressure beyond the established safe operating limit for the experiment and burst the vessel’s safety rupture disc. The class heard a loud bang followed by a strong odor described as “microwaved broccoli.”
The instructor evacuated the lab. Because procedures were not clear, a delay followed before anyone contacted Security and Health, Safety & Environment. Once the authorities were notified, the laboratory was inspected for damage, and ventilation was increased to remove the odor (which had spread throughout the floor).
Learn more about this incident in Incident pressure relief UTL Apr2014.
A researcher was attempting to change the acetylene pressure on an atomic absorption spectrometer by adjusting the pressure regulator. He inadvertently set the pressure well above 15psig, despite the signs (and the red markings on the regulator) warning not to do so. When acetylene pressure exceeds 15psi, the gas can liquefy; in this state, acetylene can suddenly and explosively polymerize. Fortunately, this did not occur, although the regulator was ruined from overpressurization.
Learn more about this incident and its implications in Incident Ames Feb2014.
A researcher was flame-sealing a glass tube using an oxy-gas torch. The tube had been dipped in liquid nitrogen to condense its contents before the sealing operation, so the researcher was using a lab wipe to handle the cold glass. The wipe ignited and fell into the laboratory waste box, which also ignited. The researcher extinguished the resulting fire using a dry-chemical extinguisher mounted in the hallway outside the lab. Neither the fire department nor Security was called, nor was the building fire alarm sounded.
See lessons learned and discussion questions in this Safety Note.