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Building laboratory safety skills critical to undergraduate education

From this week’s issue of C&EN, a letter on laboratory safety education:

I read Rudy Baum’s editorial “Educating Ph.D. Chemists” with interest, especially the discussion about safety culture in academia versus that in industry and government laboratories (C&EN, March 28, page 3). We continue to hear about a weak safety culture in academia. After many years’ experience working as a research chemist and as a health and safety manager in government, I believe the gap in the knowledge of chemistry graduates is a result of the inadequacy of the safety education process for chemistry un der graduates.

Building a safety-conscious culture requires constant reinforcement of safety in all laboratory processes. If academic institutions would incorporate safety throughout the entire undergraduate curriculum, bringing up safety at each and every laboratory session over the four years of study, then they would begin to build stronger safety cultures. This in turn requires that faculty and staff become strong leaders and proponents of safety, not just in words but by their actions, demonstrating that safety is a critical and important component of all chemistry.

Realizing that many would not know what an undergraduate student should learn about safety, Dave Finster and I wrote an undergraduate textbook, “Laboratory Safety for Chemistry Students.” [Jyllian notes: C&EN previewed the book a year ago.]

Using this or some other resource to provide lessons in safety for each laboratory session will over time build the kind of safety culture that is needed in academia. This not only serves undergraduates who go on with their undergraduate degrees to become secondary school teachers and chemists working in industry, but it can also prepare graduate students to safely carry out their research in academic labs.

Skills in laboratory safety should be essential and critical elements in the undergraduate process. The reason that safety is a critical skill is that if you don’t follow safety principles and practices, you or others can be injured or even killed. This cannot be said of other areas of chemistry study. Current educational efforts do not adequately teach the knowledge needed to develop strong laboratory safety skills. There are many ways to incorporate safety throughout the curriculum, including prelab assignments, lectures, homework assignments, etc. Academia needs to develop a strategy to teach strong laboratory safety skills to its undergraduate students.

Robert H. Hill Jr.
Stone Mountain, Ga.

I’ve covered several schools’ approaches to undergraduate laboratory safety training over the last year. Anyone else doing something interesting with their lab curricula? Who’s tried using Hill & Finster’s book and how did it go?

‘Prudent Practices’ is out, UCLA lab safety center established

I’ve got two safety-related stories out online today:

‘Prudent Practices’ Updated: The new edition of Prudent Practices in the Laboratory

is out, at last!

New Center Will Promote Lab Safety: UCLA has established a new UC Center for Laboratory Safety to study the effectiveness of things such as training and inspection programs. I think UCLA is up against two main challenges here: One is to identify metrics to measure effectiveness, especially retrospectively. The other is securing external funding–it’s not like agencies are issuing requests for proposals in the area of lab safety research (to my knowledge, anyway). But the school deserves credit for trying, and I’ll be interested to see how the center develops.

Safety at #ACSAnaheim

If you’re gearing up for the ACS National Meeting starting in Anaheim on Sunday, let me make a suggestion: Take along a copy of the Division of Chemical Health & Safety’s CHAS-At-A-Glance meeting guide (pdf). Even if safety isn’t your focus at the meeting, perhaps you can still take in a session or two. Here are the session topics:

Sunday

  • New and emerging national and international safety standards
  • Ask Dr. Safety: About reproductive hazards

Monday

  • What does a good safety program look like?

Tuesday

  • Prudent Practices in the Laboratory: The new edition arrives!
  • Program improvements following laboratory incidents

Explosion from aqueous hydrogen peroxide and acetic anhydride

We’ve got a safety letter in today’s issue of C&EN:

WE ARE WRITING to report on an accident that occurred in the chemistry department at Northwestern University on Dec. 3, 2010. Unfortunately, one of our advisees was seriously injured. The accident—a reaction mixture detonation—occurred during an attempt to synthesize 2-(tert-butylsulfonyl)iodosylbenzene, a partially soluble form of iodosylbenzene that is particularly convenient for use as an oxygen source in studies of catalytic chemical oxidations, such as olefin to epoxide reactions. The synthesis had been performed about a dozen times previously at Northwestern without incident.

The synthesis procedure was a modified version of a procedure first described by Dainius Macikenas and coworkers (J. Am. Chem. Soc., DOI: 10.1021/ja991094j), which in turn had been adapted from a tested “Organic Syntheses” preparation (Sharefkin, J. G. and H. Saltzman, in “Organic Syntheses”; H. C. Baumgarten, Ed.; New York: John Wiley & Sons, 1973; Collection Vol. 5, page 660). One modification was the use of a higher H2O2/iodobenzene ratio (25 instead of 2.8) while maintaining a similar H2O2 concentration. Likely more relevant was a second modification: the use of 35% by weight (freshly opened) hydrogen peroxide, rather than the 30 wt % solution indicated in the Macikenas procedure and used previously at Northwestern.

We do not know with any certainty what caused the explosion. However, the procedure entails combining aqueous H2O2 with acetic anhydride to form peracetic acid. The water component of the aqueous H2O2 solution should serve to remove excess acetic anhydride. We speculate that if some acetic anhydride remained after conversion of the majority to peracetic acid (the desired intermediate compound) or acetic acid (side product), the anhydride could have combined with peracetic acid to form diacetyl peroxide. This organic peroxide is known to be a shock-sensitive explosive.

If our reasoning is correct, the amount of diacetyl peroxide that potentially can form is greater in the modified reaction. Presumably, the less water initially present the greater the chance of forming the unstable organic peroxide. For a given amount of H2O2, the number of moles of water present in 35 wt % hydrogen peroxide is about 21% less than the number present in 30 wt % hydrogen peroxide. It is sobering to realize that even with 35 wt % hydrogen peroxide, the combined number of moles of water and hydrogen peroxide likely exceeded the number of moles of acetic anhydride initially present—and yet an explosion occurred. It is unclear what the margin of error is with regard to water and hydrogen peroxide concentration versus acetic anhydride concentration. However, we believe that at least some diacetyl peroxide is formed under all reaction conditions.

We emphasize that the above “explanation” and discussion are speculative. Nevertheless, there is support from the patent literature. (See, for example, U.S. Patent No. 3,079,443, “Production of a Solution of Diacetyl Peroxide in Acetic Anhydride.”) In the patented process the coreactant is aqueous H2O2.

At least until the cause of the explosion can be determined, we strongly encourage researchers to consider using alternative, nonperoxide, routes to 2-(t-butylsulfonyl)iodosylbenzene, iodobenzene diacetate, and related compounds (J. Am. Chem. Soc., DOI: 10.1021/ja1069773). More generally, we recommend that aqueous H2O2 and acetic anhydride never be combined—despite the fact that, until now, this has been a commonly used reagent combination in oxidation chemistry.

Joseph T. Hupp and SonBinh T. Nguyen
Evanston, Ill.

I e-mailed Hupp and Nguyen to see if they wanted to add anything else. Hupp replied that “Safety glasses did successfully protect the advisee’s eyes.”

Friday round-up

‘Twas a busy week back in the trenches after two weeks of (mostly) holiday. To kick off this week’s round-up, we’ll start with a new safety training video produced by Haim Weizman at the University of California, San Diego. It shows a faculty member (played by graduate student Andro Rios) modeling good safety management:

Now, chemical health and safety news from the past week:

  • 2020 Science reviews the National Nanotechnology Initiative draft EHS strategy and finds that it “holds the seed of an effective strategy” (comment accepted until Jan. 21, folks!)
  • EPA now requires testing of 19 “high production volume” chemicals, including “diphenylmethanone is used in consumer products and may be found in personal-care products; 9, 10-anthracenedione is used to manufacture dyes; C12-C24 chloroalkenes are used as metalworking fluids; pentaerythritol tetranitrate (PETN) is a blasting and demolition agent; and leuco sulfur black is a fingerprinting agent”
  • Gates, N.Y., chemical leak to be cleaned–a $3.2 million plan to “address extensive groundwater and soil contamination by trichloroethene, or TCE, and other potentially dangerous solvents that leaked years ago from Erdle Perforating, a sheet-metal company”
  • EPA fines Drew University $145,000 for hazardous waste violations–improper storage and waste labeling
  • Attorney for ‘bomb house’ owner files claim against county–$500,000 for loss and distress
  • Teen’s good intentions cause hazmat scare at North Highlands landfill–a California teen brought in a container of picric acid that had belonged to her late father; the local hazmat crew buried the container and detonated it

Fires and explosions:

  • A fire at Chemie-Pack Nederland, a chemical storage and packing company in the Netherlands; no casualties reported; In the Pipeline linked to photos at Nufoto.nl and there’s video on YouTube
  • An explosion at a Gazechim chlorine plant in France killed one and injured nine; “a leak of water containing sodium prompted the explosion,” which damaged a reservoir and caused a chlorine gas release
  • A fire at a Hexion Specialty Chemicals plant in New Zealand, believed to have started by chemical spontaneous combustion in filters full of flammable resin

Leaks, spills, and other exposures:

  • One worker died and another was injured, seemingly from some sort of chemical exposure, when they were replacing a valve at an industrial site in South Africa
  • Phosgene at a factory in China, 62 workers affected, plus 200 children living near two battery factories have high lead levels in their blood
  • Ammonia, 6,000 lbs, from a House of Raeford turkey plant in North Carolina; one worker was briefly hospitalized and 800 nearby residents were evacuated
  • Some sort of acidic mixture at Sujata Chemicals in India; three injured
  • Sulfuric acid, 200 gal, at a hotel in Las Vegas; a passerby slipped and fell in the acid and is hospitalized
  • Ferrous chloride, 150 gal, at a sewage treatment system in Arizona
  • Potassium hydroxide, 5 gal, at a town water pumping station in Massachusetts
  • An agricultural pesticide, Temik, when hunting dogs got into a supply in South Carolina; an 11-year-old was hospitalized overnight, three adults were evaluated, and the dogs died; “details of why the pesticide was there and whether it was properly stored are under investigation”
  • Fluorescein in a river in Victoria, Canada (go look at the photo–it’s impressive!); possibly a prank
  • On roads and railways: Believe it or not, I turned up nothing this week–a few things overturned but nothing seemed to actually leak.

OPRD safety issue

In the last issue of every year, Organic Process Research & Development puts together a “Safety Special Section.” In his editorial for the section, Trevor Laird describes an incident he experienced several decades ago:

[The Texas Tech] explosion brings back unhappy memories of an incident at ICI in the 1970s when I was working on novel organic conductors, and a colleague prepared less than a gram of an organic salt as a perchlorate. He left it in the desiccator to dry overnight. When he returned, the desicccator was no longer there, having been destroyed by the force of the explosion of the dry perchlorate salt, which also blew out a couple of windows. Fortunately, the laboratory was empty at the time. This incident forced ICI to rethink its guidelines on the use of perchlorates even on the gram scale.

The issue contains both literature highlights, summarized as “Safety Notables,” and original papers. The Notables feature this year discusses some safe handling guides as well as alternatives to hazardous reagents, such as 2-hydroxypyridine instead of 1-hydroxygenzotriazole for carbonyl activation and diethylaminodifluorosulfinium tetrafluoroborate and morpholinodifluorosulfinium tetrafluoroborate for fluorination.

The Notables also mentions a Process Safety Progress paper by Chandrashekhar Chandwadkar, Ghodaratollah Nasiri, and Ali Seyfzadeh of the National Petrochemical Company of Iran describing a hydrochloric acid tank explosion (DOI: 10.1002/prs.10321). From the “Notables” summary:
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Using structures to predict hazardous properties

A guest post by Arnab Chakrabarty, a chemical engineer at Baker Engineering & Risk Consultants.

Methods to elucidate structure-property relationships that would help illuminate the hazards of materials have so far been mostly focused on biological and toxicological applications. Recently, however, there has been a growing interest in estimating physico-chemical properties using similar methods. Two new papers in Process Safety Progress describe efforts to predict explosion properties and flash points of chemicals using structure-property relationships.

A collaborative work between scientists at the National Chemical Engineering Institute in Paris and National Institute for Industrial Environment and Risks (INERIS), both in France , focuses on predicting explosion properties of chemicals from quantitative structure-property relationships (QPSR; Proc. Saf. Prog., DOI: 10.1102/prs.10379). Led by Patricia Rotureau of INERIS, the group used QPSR methods to try to link topologic, geometric, electronic and quantum chemical properties of molecules to their decomposition enthalpy and electric spark sensitivity. While the deviation between the theoretical predictions and experimental results ranged from a few percentage points to 51%, the approach has potential to provide a faster alternative to experimental evaluation of hazardous properties of explosive materials.

In another paper, professor W. Vincent Wilding and his group from the Department of Chemical Engineering at Brigham Young University attempted to estimate flash points of pure organic chemicals from their structures (Proc. Saf. Prog., Proc. Saf. Prog, DOI: 10.1002/prs.10401). The idea is to eliminate the need for accurate thermodynamic data, such as the vapor pressure or boiling point of a compound, to estimate flash points. The researchers specifically investigated CxHyOzNwSvXuSit-type compounds and found that they could use structures to predict the flash points of the compounds within 3% of experimental values.

Working with nanomaterials

A guest post by Arnab Chakrabarty, a chemical engineer at Baker Engineering & Risk Consultants.

As nanotechnology marches from the boundaries of laboratories to the home of a consumer, safety concerns should not be overshadowed by the success of the technology. A recent review article by Joseph H. Lavoie, a chemical engineer at the U.S. Army’s Natick Soldier Research, Development, and Engineering Center, tackles the safety concerns of nanomaterials in manufacturing and consumer products (Proc. Saf. Prog., DOI: 10.1002/prs.10388).

Lavoie focuses on inhalation, skin exposure, disposal of nanoparticles, and limited detection ability as the main factors of concern when it comes to nanomaterials safety. More research is needed to understand the risks and how to mitigate or guard against them. Some evidence indicates, for example, that the body’s first defense mechanism against particles in the lungs, alveolar macrophages, are inhibited by carbon nanotubes and fullerenes. There are also conflicting claims about skin penetration of titanium dioxide and what the health effects might be. Scientists need to pin down these and other issues before appropriate exposure limits can be set.

Concerns like these should be well understood both by workers and consumers who are likely to be exposed to them. However, according to another review article by a group led by Jorge L. Gardea-Torresdey, a chemistry professor at the University of Texas, El Paso, recent surveys document that the very importance of assessing safety of nanomaterials is underestimated in many firms and laboratories (J. Hazard. Mater., DOI: 10.1016/j.hazmat.2010.11.020).

Gardea-Torresdey and colleagues note that there was nearly a 400% increase in nanotechnology-based products from March 2006 to August 2009. The uncertainty in nanomaterial toxicity reminds us that emerging technology research should not outpace research on the environmental and health effects of nanomaterials. The evolving document “Approaches to Safe Nanotechnology: Managing the Health and Safety Concerns Associated with Engineered Nanomaterials” by the National Institute for Occupational Safety & Health is a good starting resource for people looking to enhance their programs in this area.