Lessons from the Past

Posted on September 17, 2024 by ehs-lab-notes

By Wendy Conner

Remembering the past gives power to the present. – Fae Myenne Ng

I remember sitting in my office on September 11, 2001, when the first report of an airplane colliding with the World Trade Center’s North Tower was announced on the radio. It was believed to be an accidental crash until the second plane collided with the World Trade Center’s South Tower just seventeen minutes later. My co-workers and I listened in shock as the unimaginable and devastating events unfolded throughout the day culminating in the revelation of it being an attack on U.S. soil.

It was an event we never expected to happen. We believed we were safe, but we learned we were not as invulnerable as we thought.

It will always be a day that stands out in my memory.

But with each passing year, more people join the workforce who have no memory of 9/11. To them, it is a historical event that they have no deep emotional memory or attachment to.

The same is true of historical lab accidents. Those of us alive at the time remember when we first heard about them and the lessons learned. But time moves on. The lessons are lost without deliberate review and education.

One of the first, well-publicized, fatal laboratory safety incidents that I remember is of Dr. Karen Wetterhahn in 1997. Her death was covered by national news. I remember talking about it with my laboratory coworkers at the time.

Image of Karen Wetterhahn — Karen Wetterhahn (source Wikipedia)

Wetterhahn was an experienced researcher who authored more than 85 research papers. [2] She was aware of and utilized what was believed to be appropriate personal protection equipment (PPE) and safety measures in her studies of the effects of heavy metals on living organisms. A few drops of dimethyl mercury spilled from the tip of a pipette onto her latex glove. What was not known at the time was that dimethyl mercury rapidly permeates latex and enters the skin within 15 seconds. [3] This exposure led to her death 10 months later.

Her shocking death prompted warnings about the danger of using latex gloves with dimethyl mercury. As a result, Occupational Safety and Health Administration (OSHA) published a bulletin recommending the use of alternative substances when possible and revised PPE requirements. [4, 5]

You may not work with dimethyl mercury, but the lessons learned from Wetterhahn’s death should not be forgotten. The knowledge and use of appropriate PPE for a substance is important to keep you safe.

Benjamin Franklin said, “An ounce of prevention is worth a pound of cure.” So, take a minute or two to review the latest safety data sheets for the chemicals you are working with and the glove manufacturer’s chemical resistance guides.

Such knowledge provides you with the power to protect yourself and those around you.

Reference and Supporting Links:

[1] Science News Staff. “Mercury Poisoning Kills Lab Chemist.” Science, June 11, 1997, https://www.science.org/content/article/mercury-poisoning-kills-lab-chemist.

[2] “Tribute to Karen Wetterhahn.” Dartmouth Toxic Metals Superfund Research Program, Dartmouth, https://sites.dartmouth.edu/toxmetal/about-us/a-tribute-to-karen-wetterhahn/.

[3] “Karen Wetterhahn.” Wikipedia, March 27, 2024, https://en.wikipedia.org/wiki/Karen_Wetterhahn

[4] Cavanaugh, Ray. “The dangers of dimethylmercury.” Chemistry World, February 19, 2019, https://www.chemistryworld.com/opinion/the-dangers-of-dimethylmercury-/3010064.article.

[5] United States, U.S. Department of Labor, Occupational Safety and Health Administration. “OSHA Hazard Information Bulletins – Dimethylmercury.” Directorate of Technical Support and Emergency Management, Office of Science and Technology Assessment, March 9, 1998, https://www.osha.gov/publications/hib19980309.

Glove Guides:

OSHA Personal Protective Equipment guide, pg 26-29: https://www.osha.gov/sites/default/files/publications/osha3151.pdf#page=25

Berkely glove selection guide: https://ehs.berkeley.edu/glove-selection-guide#GCC

Ansell Chemical Resistance Guide: https://cdn.mscdirect.com/global/media/pdf/search/ansell/ansell-chemical-glove-resistance-guide.pdf

Peroxide Formers: The Silent Ticking Time Bomb

Posted on September 17, 2024 by ehs-lab-notes

By Wendy Conner

Man's hand facing up holding dynamite bundle with time bomb on blackboard background with chalk words 'tick tock'. — Image source: Adobe Stock

It might surprise you that peroxide is a danger. Almost all of us have used hydrogen peroxide at home to clean wounds or as a household cleaning aid. It is for this reason that many don’t consider it a danger.

Common household peroxide is a 3% solution of the simple peroxide H2O2 (H-O-O-H). Peroxides and peroxide formers used in the laboratory pose a greater safety risk than the brown bottle of hydrogen peroxide in your bathroom.

Peroxides are widely used in research laboratories because of their exceptional reactivity and oxidative capacity. The oxygen-oxygen bond in the peroxide (R-O-O-R’) is relatively weak and tends to spontaneously change to form more stable molecules.

As a class, peroxides are exceptionally prone to violent decomposition initiated by several mechanisms…. [1] They are among the most hazardous substances commonly handled in the laboratory because they are highly flammable; extremely sensitive to shock, heat, spark, friction, impact, and light; and react readily with strong oxidizing and reducing agents. (see videos in experiment links below)

So, what are peroxide forming compounds?

Peroxide formers are compounds that react with the oxygen in the air or form a compound with a peroxide group when concentrated.

The slow reaction between organic chemicals and oxygen in the air under mild conditions can produce unstable and dangerous hydroperoxide and peroxide products. This means that a bottle sitting on a shelf can, over time, become a silent ticking time bomb without you even realizing it.

Peroxide formers are grouped into three classes based on the method of formation. (peroxide former list)

Class A can form explosive peroxide levels just sitting on the shelf, can form in an unopened container, and some will separate from solution.

Class B can form peroxides when concentrated by evaporation, distillation, etc. They are often volatile solvents, and the repetitive opening of a container could allow enough evaporation to reach an explosive level of peroxide concentration.

Class C are formed when the compound polymerizes.

Common misconceptions concerning peroxide formers and why they are potentially dangerous:

My bottle of Tetrahydrofuran has an inhibitor so it’s safe to keep around for years. – Wrong! Just because the bottle of peroxide-former has an inhibitor, it has not been rendered safe to keep beyond safety guidelines. The antioxidant inhibitors are used up binding to the oxygen over time as it prevents peroxide formation. The inhibitor will eventually deplete to a point where peroxide formation will occur. It just delays the process.

I use ethyl ether all the time and haven’t had any accidents. I know what I’m doing…. – Accidents in laboratories happen when attention drifts, staff become complacent, or proper procedures are not followed when working with peroxide-forming compounds (see Berkley and Princeton accident reports).

Some key points when handling and working with peroxide-forming compounds are:

1 . Do not open the container if:

crystals are visibly present;
precipitate has formed;
an oily viscous layer is present; or
the container was opened more than 12 months ago, or it is past the expiration.

2. Material must be properly disposed of by/before:

12 months of opening for Class B & C;
3 months of opening for Class A and distilled peroxide-forming solvents with no stabilizer; and/or
expiration date on the label.

3. If beyond the above dates:

do not open because it could be shock-sensitive;
call Environmental Health and Safety (EHS) for technical assistance; and
place a Danger Warning on the container.

4. Do not use metal spatula with peroxides. (Watch sodium with hydrogen peroxide video)

5. Put a warning on any container that it is a peroxide-former. (See IU CHP 3.17 for all Procedures for Safe Handling and Management of peroxide forming chemicals )

It is important to know what peroxide-forming compounds are in your lab, to order only what you will use within the disposal window, and to record the date received and opened so you know if they are safe to handle. We recommend using a label like the one below to make sure laboratory personnel are aware of the possible danger and to remind you to be sure these chemicals are disposed of before they become a safety issue. Sheets of printed labels can be requested from EHS or you can print your own with the templates below.

Don’t be caught by the peroxide-former ticking time bomb.

Reference:

[1] Clark, Donald E. Ph.D. “PEROXIDES AND PEROXIDE-FORMING COMPOUNDS.” Texas A&M University, 2000, https://www.bnl.gov/esh/cms/pdf/peroxides.pdf.

Warning Label Templates:

Peroxide former labels AVERY 5161

Peroxide former labels AVERY 5162

Videos of experiments with H2O2:

Spontaneous Combustion With H202 (Hydrogen Peroxide) by Nick Uhas

Slow Motion Peroxide Explosion posted by Mike Davis

One Time Magic. Twice Could Be Tragic.

Posted on September 17, 2024 by ehs-lab-notes

By Winston Baity

Latex gloved hands — Image Source: Adobe Stock

Reduce, Reuse, and Recycle are the guidelines for sustainable life. Recycling is very important as waste has a huge negative impact on the environment. Personal protective equipment (PPE) is your last line of defense to any hazards you would be working with inside the research laboratory. Commonly reused PPE in the laboratory includes your eye protection and lab coat.

Gloves are another commonly used form of PPE in your research laboratory but may not be designed for reuse. Researchers should refer to safety data sheets (SDS) and/or any search engine in relation to the potential hazards when deciding which gloves to choose for the task at hand. Get it?

Some of the basics:

Select gloves that are resistant to the chemicals you may be exposed to.
Select gloves of the correct size and fit for your hands.
Before use, check gloves for physical damage such as tears or pin holes.

Plainly put, researchers should not reuse lab gloves once taken off (unless they are designed for reuse). The risk is just not worth it. Reusing disposable gloves may increase the risk of exposure to biological hazards like viruses and bacteria, chemical hazards, and other hazards through microscopic tears. Washing gloves can disrupt the integrity of the glove. After your gloves are worn and properly removed, they should be disposed of properly.

Follow all safety guidelines, use good laboratory practices and refer to your standard operating procedure. Your safety is your responsibility.

For more information, please contact Environmental Health and Safety at protect.iu.edu.

Glove Guides:

OSHA Personal Protective Equipment guide, pg 26-29: https://www.osha.gov/sites/default/files/publications/osha3151.pdf#page=25

Berkely glove selection guide: https://ehs.berkeley.edu/glove-selection-guide#GCC

Ansell Chemical Resistance Guide: https://cdn.mscdirect.com/global/media/pdf/search/ansell/ansell-chemical-glove-resistance-guide.pdf

A Quick Fix for Under Hood Flammable Cabinet Doors

Posted on September 17, 2024 by ehs-lab-notes

By Mendy Foster

(Originally posted in Winter 2015 Lab Notes)

If the right-side door to your flammable cabinet located under the hood won’t close properly, there could be a simple fix. Take a moment to check the latch mechanism across the top-front of the open cabinet. A common model found on campuses has rectangular slots with a sliding latch mechanism (fig 1). The left side latch should slide over when the left door is closed, creating space in the right-latch opening.

Frequently, the L bracket attached to the left door has shifted position and does not push against the latch mechanism. This leaves the mechanism positioned so that it blocks the second door from closing. This issue can be corrected by adjusting the angle of the left door bracket to align with the lever. If the bracket is aligned correctly, you should be able to see the lever in the right-hand slot slide out of the way when you close the left door. Once the bracket alignment has been corrected, completely tighten the bracket screws to secure it in the correct position.

We depend on flammable cabinets to slow the spread of fire to chemicals, but full protection from this safety device requires that both doors are closed. If you notice yours is not functioning properly, please take a moment to address the problem or find assistance.

Image of flammable hood door hing mechanism and L bracket. — Figure 1: The L bracket secured to the flammable cabinet door must connect with the metal lever on closing. If it does not, the second door will not be able to close properly. This bracket can easily be adjusted with only a screwdriver. (photo taken by EHS)

Five Simple Lab Safety Hacks

Posted on September 17, 2024 by ehs-lab-notes

By Mendy Foster and Tuan Nguyen

(Originally published in Spring 2016 Lab Notes)

Want to avoid frequent safety mistakes but don’t have the time?

Try adjusting your approach and even imagining a few safety hacks. Simple changes in everyday habits can go a long way towards keeping your lab in compliance. Not every solution is one-size-fits-all but consider the frequently seen scenarios below. They illustrate how some common issues can be mitigated by changing your approach.

1. Does your lab have a stockpile of balance tubes?

Rather than labeling each vial individually, use group labeling. Labeling the storage rack “water” will keep you in compliance, as long as the tubes are returned to the rack at the end of the run.

Group labeling can also be used to identify the chemical contents when storing boxes/racks containing multiple vials of stock solutions, sample fractions, or mini-prep tubes. Just remember that if you remove a tube and choose to store it separately, an individual label will be needed.

2. Do you have chemicals that are stored upside-down or on their side?

Your immediate reaction may be “no,” but think again. Sideways and upside-down storage is frequently seen when items are stored in drawers, when smaller bottles are lost inside chemical cabinets, and when conical tubes are inverted so they can stand on their own.

Without support, these items easily topple over or must be placed upside-down. A quick way to reduce the chance of chemicals leaking/spilling because they were not stored upright is to place these items in racks. Don’t have enough racks or find that standard racks don’t fit in your space? Try reusing the foam bases that come with conical tubes. It may be the low-profile storage solution you need to keep chemicals upright in drawers. The foam can also be easily broken into smaller sections to fit your needs when shelving or bench space is limited.

3. Is chemical segregation a recurring battle?

Label cabinets or secondary containers by chemical type or hazard class (i.e. Organic acids). Then it just takes a moment for all workers to place items in the correct location.

4. Are chemicals going to waste because of age, or are forgotten chemicals creating safety risks?

If expired chemicals are a problem, imagine what better inventory management would look like. In the long term, it could save time, reduce costs, improve safety, and free up lab space.

Even small changes could help.

Date bottles with received and opened date and follow a “first in, first out” policy for identical items.

Determine if changes in lab activities will alter chemical usage. Be proactive in adjusting inventory when lab activities or procedures are expected to change. Likewise, be retrospective when activities have evolved. This is an easy time for sensitive chemicals to be forgotten.

Record the expiration dates of time-sensitive chemicals (i.e. peroxide formers) in your inventory list. Do a quick date check when ordering new supplies.

5. Are open waste containers frequently left on your benchtop long after the experiment is done?

If you don’t have bench top containers with lids, make it a habit to empty these into larger covered waste containers at the end of the day. Also, you may find that using waste containers that are sized to the experiment reinforces this habit.

While every lab has its own challenges, we hope this list encourages you to create and employ your own safety hacks.

EHS Laboratory Safety Staff

Posted on September 16, 2024 by ehs-lab-notes

Group of people. Crowd of people silhouettes. — Image source: Adobe Stock

In recent years there have been several changes to the Environmental Health and Safety (EHS) staff. We want to give you the opportunity to learn a little bit about the current EHS Laboratory Safety personnel.

Bloomington

Nathan Herr

Nathan (Nate) Herr is the IU Bloomington Laboratory Safety Manager and has over 12 years of experience in laboratory safety, hazardous materials management, and environmental remediation. He is a Certified Hazardous Materials Manager and Chemical Hygiene Officer. In his spare time, he enjoys reading, sports and spending time with his family.

Robin Johnson

Robin Johnson has a B.S. and M.S. in Environmental Science from Indiana University. She has laboratory experience as a technician and as a quality control specialist, in both academia and private industry. She has been a Laboratory Safety Specialist at IU Bloomington since 2019 and is a Chemical Hygiene Officer.

Mehmet Soylu

Mehmet Soylu joined the IU Bloomington EHS team as a Laboratory Safety Specialist in 2023. He is an educated veterinary graduate and has a PhD in physiology. He has research and teaching experience in the same field. Laboratory safety is a new career path for him and matches his safety-oriented personality.

Indianapolis

Wendy Conner

Wendy Conner joined the IU Indianapolis EHS team as a Laboratory Safety Specialist in 2018 with over 20 years of laboratory experience in environmental testing (with ten of those years as a safety team member). In her spare time, she enjoys knitting and reading.

Danielle Williams

Danielle (Dani) Williams is a Laboratory Safety Specialist and has served at IU Indianapolis since 2021. She earned a degree in forest engineering from Universidade Federal Rural de Pernambuco in Recife, Brazil. Dani has a great interest in Environmental Health and Safety. English is her second language, and she has been living in the US since 2017. When she has free time, she loves to spend it with family, friends or traveling.

Julie Simon

Julie Simon earned a B.S. in chemistry from Indiana University Bloomington and a M.S. in chemistry from the University of California-Irvine. She has industry experience as a process chemist and joined the IU Indianapolis team in February 2024 as a Laboratory Safety Specialist. She is a dog lover and enjoys hiking with her playful pup.