Tag: radiation-nonionizing-laser

Related specifically to laser radiation

Found: “Class 2” laser pointers not as advertised

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, nleon1@jhu.edu. 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).

Protect your eyes from high-intensity light

Protect your vision when working with UV germicidal lamps; lasers; welding and arc lamps; or other highenergy light sources. Special goggles limit the amount of light that can reach your eyes and skinThe type and amount of protection depends on the frequency, nature, and intensity of light. Learn more in Light eye protection.

What eye protection do I use?

There are many different types of protective eyewear available, and each one is designed to protect against a different hazard. Having the wrong type of safety eyewear can be worse than not wearing eye protection at all. Learn about the basic types in Choosing eye protection.

This Hopkins Safety Note is the start of a series on eye protection, so look for future notes covering the different types in detail.

Don’t buy cheap lasers!

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.

Rockwell laser accident database

Since 1964, Rockwell International has maintained this database of laser incidents. Although reporting is voluntary, the sheer number of incidents in the database gives one pause.

One of the fastest-growing areas of laser incident is the “aircraft illuminated with laser” event. Shining lasers at aircraft is illegal in Maryland, punishable by up to 3 years in prison and a $2,500 fine. In the City of Ocean City on Maryland’s Eastern Shore, laser pointers are banned entirely.