8/8/2017
by Sarah Arrowsmith
A Riveting Tale of Lab Safety
Let’s get real for a moment. When was the last time you picked up the SDS for a chemical you recently ordered and actually looked at it? Even just a passing glance? I think it is pretty unlikely. Don’t worry, you aren’t the only one. Join me in today’s blog quest to change that.
Safety Data Sheets (SDS), formally known as the Material Safety Data Sheets (MSDS), are defined as a document provided by the chemical manufacturer to communicate to downstream users the hazards associated with working with a particular chemical or reagent. Ideally they are supposed to be easy to read and easy to understand, especially for first responders. They are also required for every chemical by OSHA, although there are some exceptions for reagent kits, and mixed solutions (Hazard Communication Standard: Safety Data Sheets, 2017).
Over the years, there have certainly been arguments about the usefulness of these sheets that just collect in binders above lab managers’ desks collecting dust. Have you seen the Right to Know Station at my desk? I don’t think it’s been touched in years. Derek Lowe from the Science Magazine certainly had a lot to say about the subject. (You can read his opinion blog post here.) He claims that SDS are more a lawyer’s declaration of liability (or lack thereof), rather than a useful document. It is an interesting point for sure.
However, as ASU EH&S requires us to submit a chemical inventory, complete with a list of hazards associated with particular chemicals. I had the glorious job of gleaning the SDSs for over 1,200 chemicals that we store for our annual lab registrations. (Someone get me a donut, stat!)
Let me tell you what I’ve learned from the experience. I have found that we have a dozen and some fantastically dangerous chemicals being stored with no extra precautions taken. (They have now been moved and stored appropriately, of course.) I’ve also found a dozen and some not so dangerous chemicals taking up valuable space in extra secure storage locations. I’ve also found chemicals being stored together, that probably shouldn’t be stored together. Let me explain.
A Tale of Nitric Acid
Did you know that Nitric Acid and Acetic Acid (okay, Nitric Acid and just about everything else if we are honest) can’t be stored together? Did you know that explosions from storing these two acids together are actually very common across the US in university labs? Including ASU? Tufts University put out a good article on the subject, you can read it here. Just for good measure Georgia County Fire Department’s report here on an explosion at Maryland University that injured two students is also good reading. Note that this explosion happened in a hood, and injures still occurred.
The SDS for nitric acid also gives a very helpful list of other chemicals that it should contact. Ethanol being one of them and we store A LOT of ethanol. Other incompatible chemicals include acetic acid, acetone, and flammable substances such as organic chemicals. The American Chemical Society states the most common accidents are from mixing nitric acid in the wrong waste container (American Chemical Society, 2017). We have isolated our nitric acid in its own cabinet; please be mindful that you are not storing incompatible chemicals with it.
A Tale of Diethyl Ether
After reading the SDS for Diethyl Ether, we found that bottles form peroxides if they are left to sit unused for more than 3 months. Peroxides often form around the cap of the bottle, and when an unsuspecting researcher comes by to use the chemical, friction caused by twisting the cap can cause an explosion. Not good. We promptly had EH&S remove the potentially dangerous bottle. Did you know there are a number of other chemicals that also form peroxides? Dartmouth College has a good explanation and list here. Likewise, do not store ethers and other highly volatile solvents with oxidizers. Especially do not store in non-chemical refrigerators. Regular refrigerators can spark when they cycle on and off and that is the perfect combination for an explosion (yikes!).
A Tale of Sodium Azide
We use Sodium Azide in our lab. Yes, this is the explosive stuff they put into air bags. Accidents and deaths from explosions were frequent enough to warrant our local airbag production plant, TRW, to recently cease use of it. You are welcome to read the news article. The SDS reveals that sodium azide is highly toxic in its powdered form (which we have). It is fatal if swallowed and can be fatal when in contact with skin. It has the highest health danger rating for our lab (NFPA rating 4-0-3). It reacts violently with metals (do not store in flammable cabinet, it can react with the cabinet itself). It also reacts with methylene chloride, DMSO and sulfuric acid. If you need to use this chemical, it is stored in a separate plastic tub labelled “poisons” in the dry chemical cabinet.
Moral of the Story
SDSs have a wealth of useful information regarding the chemicals you are using. They aren’t useless documents to be stuffed in a binder never to be seen again. I know we are all busy and I know how tempting it is to simply purchase chemicals and not think about all the extra papers that come with the packing slip. I implore you to read up on each chemical you are buying and using, preferably before you buy and use.
While we are on the subject, please attach digital SDS sheets to your chemical orders in Quartzy! You can find what SDS we already have on our shared drive here:
S:\Research\Swette Center General Documents\Chemical Inventory\SDS
A regard for your safety must begin with you. You are the user of chemicals in the lab. It is your duty to understand what you are working with and your responsibility to handle, store and dispose of it properly. If you have questions or need help, please come see your friendly neighborhood lab manager.
References
(2017). Retrieved from American Chemical Society: https://www.acs.org/content/acs/en/chemical-safety/guidelines-for-chemical-laboratory-safety/resources-supporting-guidelines-for-chemical-laboratory-safety/incompatible-chemicals.html
Hazard Communication Standard: Safety Data Sheets. (2017). Retrieved from United States Department of Labor OSHA: https://www.osha.gov/Publications/OSHA3514.html
Helpful Links
ASU’s Hazard Communication Plan
Sarah Arrowsmith is the Research Laboratory Coordinator and Safety Compliance Officer (and cartoonist!) for the Biodesign Swette Center for Environmental Biotechnology