Tag: physical hazards

General physical hazards information

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.

Incident report: Tank damage, Krieger Hall, May 2014

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.

Incident report: Regulator overpressure, Ames Hall, Feb 2014

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.

Using extension cords, power strips, and surge suppressors

Every office and lab uses electrical equipment, but the wall socket is not always in the right place. An extension cord, power strip, or surge suppressor offers a quick way to fix this situation. Sometimes, though, this is not a good thing.

Learn about fire and other hazards from extension cords and their ilk in Extension cords v2.

When do you need safety eyewear? Always!

Even if you are not doing anything that “needs” safety eyewear, you still need safety eyewear in the lab!

You do not have control over all hazards in the lab—one of your fellows may walk in with a chemical bottle and suddenly drop it on the bench in front of you, or a pressurized system (like a gas cylinder regulator) may throw off a part. You are exposed to more hazards than you personally are handling—choose eyewear according to your exposure, not your specific work. There have been incidents at Homewood where uninvolved labmates were suddenly involved in someone else’s accident.

Wearing appropriate eyewear in lab or shop is also a mark of a professional scientist or engineer. If you have to be told to put on your safety glasses or goggles when visiting an industrial or governmental facility, you will be considered unprofessional, and you may not get the job for which you are interviewing. Acquire the habit of wearing safety eyewear.

Algorithm for deciding whether you need safety eyewear:

  1. Is the work you’re about to do hazardous?
    If YES, wear appropriate eyewear. Obviously, you personally need it.
  2. Is anyone else in the lab doing hazardous work?
    If YES, wear appropriate eyewear. You are exposed to their hazards.
  3. Are chemicals or compressed gases stored or used in the lab at any time?
    If YES, wear appropriate eyewear. You do not have control over falling chemical bottles, poorly secured pressurized parts, etc.
  4. Is it possible anyone else will bring hazardous work into the lab while you are there?
    If YES, wear appropriate eyewear. Somebody can walk in and drop a chemical bottle at any time, so you need to be ready.
  5. Is it possible that you will “forget” to put on your eyewear if you decide to do hazardous work—or simply not do it because “you’re just doing one little thing?”
    If YES, wear appropriate eyewear.
  6. Are you sure you won’t do anything hazardous in lab today, no one will walk in with hazardous materials or equipment, nothing hazardous is stored in the lab, and you want to exhibit bad professional habits?
    If YES, you DON’T need to wear safety eyewear.

Lab air can kill you

Equipment, experiments, and people often get dirty—a lab bench covered with cement dust, a drill press clogged with metal shavings, wet glassware that needs drying, or even a researcher covered with sawdust after cutting a wooden part. Some people look to the compressed air tap or cylinder in the lab as a quick way to clean off.

Did you know this can kill?

Even a relatively low-pressure stream of air can propel chips, dust, and parts through the air at high velocity; the flow from a 20psi air line can be supersonic. If this material strikes someone, it can cause serious injury. If the injury is to the eye, the victim may be permanently blinded.

Even worse, a few tens of psi pressure can easily inject air beneath the skin, inflating body parts like balloons—and causing excruciating pain. If air reaches the bloodstream, it can cause air embolisms—blockages in narrow blood vessels—as well as clots & ruptures in vital areas such as the brain. Uncontrolled air injection can be deadly.

Read tips for safely handling compressed air at Compressed air misuse.

Prudent practices in the laboratory

The National Academy of Sciences publishes the definitive book on lab safety. It’s technically written for chemical labs (hence the full title: Prudent Practices in the Laboratory: Handling and Management of Chemical Hazards) but it’s got substantial information on other hazards such as liquid nitrogen and other cryogens, centrifugation, etc. A large portion of the book is devoted to management topics like how to effectively manage chemical inventories and how to assess the hazards of a chemical you haven’t used before.

A PDF version of the book may be obtained from the National Academy Press. The hardcover book is $99.95, but the PDF is free if you register.

Sharps do not belong on bench tops!

Something I see all too frequently in labs is sharp objects like syringe needles and razor blades left out on lab benches without shielding. Proper sharps handling is extremely important–besides the usually-painful cuts and punctures that result, any materials on the sharp (pathogens, chemicals, the lead solder you were scraping) now has direct access to your bloodstream. Yuck!

Please note these basic facts about sharps handling:
  1. Anything that can cause a cut, puncture, or other skin penetration is a sharp. This includes needles/syringes, knife blades, Pasteur pipets, broken glass, etc.
  2. Discard disposable sharps such as needles and Pasteur pipets immediately into sharps containers when not in use. Generally, recapping is not recommended for disposables, although if they are required for more than one use a “one-handed scoop” method is allowed to place the shield on the sharp.
  3. Never leave non-disposable sharps such as X-Acto blades unshielded on the bench when not in use. Place them in containers for cleaning or placed in holders not on the bench. It is typical in my experience for students to place the sharps in Petri dishes on the shelf above the bench. In this location they are easily accessible without being potential cut injury sources when someone tries to pick them up off the bench. There is also less chance of the sharp being knocked on the floor or covered by other lab detritus and becoming a hidden hazard.
  4. Dispose sharps only in approved sharps containers such as those sold in Mudd Store. Things should not stick out the top of the container—they should be fully enclosed. Never place sharps directly in a biohazard box or other trash container.
  5. When a sharps container is 3/4 full, replace it immediately—the containers are sharp-resistant, not sharp-proof, and forcing the lid on can sometimes cause a needle or blade to puncture the container. Place the sharps container in a biohazard box for disposal. (If the sharps are radioactive, contact Mina Razavi, the Homewood Radiation Safety Officer, for additional instructions.)
  6. If glass becomes broken, use tongs or a brush and dustpan to collect the shards for disposal in the sharps box—using hands is a frequent source of injury and hazardous materials injection.