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As I look back on the chemistry coursework I took as an undergrad, a few classes stand out as especially useful over my career. First some qualifications: I became an organic chemist because I found it to be a good “fit” for my brain. So, organically oriented courses were obviously useful. The chemistry department at my alma mater followed guidelines for the ACS Certified curriculum. Thus required coursework was prescribed and completed.

Chemistry coursework of enduring value.

Sophomore Organic Chemistry:  Fortuitously, I took 2/3 of my general chemistry in the preceding summer, so I was able to take organic chemistry in my freshman fall term. This was the great awakening. It was crystal clear that this was what I was meant to do. The benefits from a course on organic chemistry are many. Foremost on the list is that it is structurally and mechanistically oriented. The cognitive benefit is that a structural and mechanistic approach can render the subject a bit less abstract. At least to highly visual people like myself.

Molecules are tiny objects with even tinier places on them where certain things can happen. Reaction chemistry is revealed as a graphic sequence of specific events on specific objects. This allows the mind to put together patterns of functional groups and reaction motifs. In my view, a year of organic chemistry is the reward for slogging through a year of general chemistry. Gen Chem doesn’t make you a chemist. A tech perhaps. But gen chem is to the chemistry curriculum as The Hobbit is to The Lord of the Rings- a necessary prelude. That is what I used to tell students, anyway.

Qualitative Analysis: This was the third quarter of a 3-quarter sequence of freshman chemistry. It was heavily lab oriented with a focus on the separation and identification of inorganic cations and anions. It was substantially descriptive chemistry where clever schemes were used to isolate ionic species.

Analytical Chemistry: This is where you really begin to feel like a chemist. We all learn skills in this class that last. It is measurement science and error analysis. Every chemical scientist should have a solid foundation in wet chemistry.

Instrumental Analysis: This class was taken after Analytical Chemistry and built upon learnings from it. I’d offer that time spent on learning how your detectors work and their limitations is invaluable.

Organic Qualitative Analysis: I’ve come to learn that this class was an unusual experience. We learned to identify organic substances using fundamental means for 1982. Melting points, melting points of derivatives, NMR (60 MHz!!) & IR spectra, solubility, sodium fusion, Lucas Test, 2,4-DNP-hydrazones etc. We were required to get three data points per unknown to conclude that we had identified the substance. An indispensable resource was a compendium of derivative properties. A challenging but good experience.

Undergraduate Research: Two years of this experience was invaluable as a prelude to grad school. The asymmetric reduction of ketones (1982-84) work here lead to my doing a doctorate in asymmetric C-C bond forming chemistry and a postdoc in catalyzed C-H insertion chemistry. This activity is a must for those who want to pursue post-graduate work.

Advanced Organic Chemistry: What can I say?

Advanced Inorganic Lab: Good experience. Did some glass blowing. Worked on a vac line, tube furnace, and in a glove box. Good intro to airless work which would be important in grad school.

Chemistry coursework that was inadequate.

Inorganic Chemistry: I took this class in a time when symmetry and spectroscopy topics were an emphasis in the textbooks. Maybe it is still like that. But I maintain that we were gypped in that symmetry operations were covered at the expense of descriptive inorganic chemistry.

Physical Chemistry: It seemed as though the mathematical gyrations were more important than what the relationships actually meant. Statistical mechanics was played down in favor of more time on quantum mechanics. On entrance to grad school of the 5 qualifier exams taken, stat mech was the only one I failed.

Coursework outside of chemistry that has been of enduring value.

Microbiology: My only college bio class. I swear that this class has saved me from food self-poisoning more than I realize. That is a lifelong benefit, but so was the insight into a fascinating world. The course included an intro to immunology which also has been useful.

Communications: I made great strides in learning how to do public speaking.

Russian Language:  Took only 1 year- just enough to be dangerous. But the history and politics of Soviet Russia was fascinating. It was of nearly zero help when I eventually visited Russia years later on a business trip.

Computer Programming: We learned Pascal. Should have taken more classes.

Air Force ROTC: The biggest benefit was that I learned I am not military material in any sense. But, communication and the history of air power was interesting. I couldn’t march to save my life.




One of my work duties is to give safety training on the principles of electrostatic safety; ESD training we call it. The group of people who go through my training are new employees. These folks come from all walks of life with education ranging from high school/GED to BS chemists & engineers to PhD chemists. In order to be compliant with OSHA and with what we understand to be best practices, we give personnel who will be working with chemicals extensive training in all of the customary environmental, health and safety areas.

I have instructed perhaps 80 to 100 people in the last 6 years. At the beginning of each session I query the group for their backgrounds and ask if it includes any electricity or electronics study or hobbies. With the exception of two electricians in the group, this survey has turned up a resounding zero positive responses.

Admittedly, there could be some selection bias here. It could be that people with electrical knowledge do not end up in the chemical industry. This agrees with my informal observations. But I’m not referring to experts in the electrical field. I refer to people who recall having ever heard of Ohm’s law. One might have guessed that the science requirements for high school graduation may have included rudimentary electrical concepts. One might have further suspected that hobby electronics could have occupied the earlier years of a few attendees. Evidently not. And it does not appear that parents have been very influential in this matter either.

I’m struggling to be circumspect rather than righteous. It is not necessary for any given individual to have learned any particular field of study. It is not even necessary for most people to have studied electricity. But it is important for a core of individuals to have done so. So, where are they? And why aren’t more people curious enough to strike out on their own in the acquisition of electrical knowledge?

Back to electrostatics. In order to have a working grasp of electrostatic principles, the concept of the Coulomb has to be conveyed. Why the Coulomb? Because it is the missing piece that renders electrostatic concepts as mechanistic. It is my contention that a mechanistic grasp of anything will help a person reason their way through a question. The alternative is rote memorization. This betrays my mechanistic approach inculcated from many years of study in chemistry.

To be safe but still effective as an employee, a person needs to be able to discriminate what will and what will not generate and hold static charge to at least some degree in a novel circumstance. By that I mean how accumulated or stranded charge can form and what kind of materials can be effectively grounded. If you are working with bulk flammables, your reflexes need to be primed continuously to recognize a faulty path to ground in the equipment around you. At the point of operation, somebody’s head has to be on a swivel.

It is possible to cause people to freeze in fear and over-react to unseen hazards like static electricity. But mindless spooking is a disservice to everyone. To work around flammable materials safely requires that a person understand and respect the operating boundaries of flammable material handling. Those boundaries are grounding and bonding (see NFPA 77), avoiding all ignition sources, good housekeeping, and maintaining an inert atmosphere over the flammable material.

Much of electrostatic safety in practice rests on awareness of the fire triangle and how to avoid constructing it.

Back to electrical education. There are numerous elements of a basic understanding of electricity that will aid in a person’s life, including safely working around flammable materials. One element is the concept of conduction and what kinds of materials conduct electric current. Another is the concept of a circuit and continuity. Voltage and its relationship to current follows from the previous concepts.

I would offer that the ability to operate software or computers is secondary to basic knowledge of how things work.

Connecting these ideas to electrostatics are the Coulomb and the Joule. One volt of potential will add one Joule of energy to one Coulomb of charges. One Ampere of current is one Coulomb of charges passing a point over one second. Finally, one Ohm is that resistance which will allow one Ampere of charge to move by the application of one volt.

For a given substance- dust or vapor- a minimum amount of energy (Joules) must be rapidly released in order to cause an ignition. This is referred to as MIE, Minimum Ignition Energy, and is commonly measured in milliJoules, mJ.

A discussion on sparking leads naturally into the concept of power as the rate of energy transfer in Watts (Joules per second), connecting to both the Joule and Ohm’s Law. Rapid energy transfer is better able to be incendive owing to the finite time needed for energy to disperse. Slow energy transfer may not be incendive simply because the energy needed to maintain combustion is dispersed into the surroundings.

A discussion of energy and power is useful for a side discussion on how the electric company charges for energy in units of kilowatt hours (kWh). This is a connection of physics to money.

The overall point is that a rudimentary knowledge of electrical phenomena is of general use, even in the world of chemical manufacturing. I often hear people talk about the importance of “tech” in regard to K-12 education. By that they seem to say that using software is the critical skill.  I would offer that the ability to operate software or computers is secondary to basic knowledge of how things work. Anyone with a well rounded education should be able to learn to use software as they need it.

In the course of my forays into chemical sourcing or searching for data, I have begun to notice something about product entries in the online Sigma-Aldrich catalog. I’m finding that since the acquisition of Sigma Aldrich by Merck KGaA, MilliporeSigma as it is now known, many of the compounds that I find listed say the product has been discontinued. Is it just fortuitous, or is it not? Is the catalog collection being trimmed?

Have I been collecting data? Pffft! Of course not, silly. It’s just the subjective experience of having found few if any Aldrich catalog entries labeled as discontinued over the past few decades. Recently I’m landing on the pages of discontinued products. Hmmm.

Over the many years, buying reagents from Aldrich has saved countless chemist-days in lab productivity. In fact, the availability of their huge collection of chemicals has driven the direction of much research out there based simply on the availability of reagents for purchase.

I blame the MBA’s. This has the smell of overly smart weasels marketing people.


I’ve been using a Mettler-Toledo (MT) RC1e reaction calorimeter for about 6 years. Our system came with MT’s iControl software, RTCal, and 2 feed pumps with balances. Overall it has proven its worth for chemical process safety and has helped us understand and adjust the thermal profile of diverse reactions. Like everything else, MT’s RC1e has many strengths and a few weaknesses.

The RC1e’s mechanical side seems reasonably robust. Our instrument sits in a walk-in fume hood resting on a low lab benchtop supported by an excess of cinder blocks- it is a heavy beast. During installation we discovered that the unit would not achieve stable calibration with the hood sash down. The control box mounted on the instrument didn’t work properly on installation. After a trip to the repair shop, the box was returned as functional but without finding the fault.

Recently we had a mixing valve fail in the heat transfer plumbing, resulting in down time. Diagnosis of this was unsuccessful over the email and phone, necessitating a service call. Parts may not be inventoried in the US and consequently must come from Switzerland. Expect Swiss prices and less than snappy delivery. Hey, it’s been my experience.

A chiller unit is required for RC1 operation and can add 15-30k$ to the setup cost. Users will have to contend with the loss of floor/hood space in the lab for the chiller and RC1. Chillers can take many hours to get down to the set temperature. Given that RC1 experiments can also be lengthy, plan accordingly. Our (brand new Neslab 80) chiller requires nearly 2 and 1/2 hours to get from +20 C to -20 C, which is the upper chiller temperature we use, depending on the reaction chemistry. For reactions that are on the sporty side, we’ll drop the chiller to – 50 C.  This is near the  minimum temperature for the water-based chilling fluid we use. Early on I opted for an aqueous lithium formate solution with a very low freezing point. It’s a little spendy, but a pool of it on the floor cannot warm up to become combustible and an ESD ignition hazard. Also, it is odorless.

The chiller required the wiring-in of a dedicated single-phase 240 VAC circuit. With the chiller using single-phase and the RC1e using 3-phase 240 VAC, it is important to assure that one cannot inadvertently connect into the wrong power circuit (idiot proofing). The chiller plug design should already prevent this. It is critical that the electrician is alert to this and does NOT jury-rig the plugs to use the same style of connectors because he has only one style in the parts bin.

Some comments on the collection and interpretation of RC1 thermograms.

  • It is critical that those who request RC1 experiments understand the limitations of the instrument. For instance, we use a 2 Liter reaction vessel with a 400 mL minimum fill volume. Refluxing is not allowed owing to the huge thermal noise input from the reflux return stream. Special equipment is said to be available for reflux.
  • Experiments must be carefully designed to elicit results that can answer questions about feed rates and energy accumulation.
  • Like many instruments, the RC1 needs a dedicated keeper and contact person for inside and outside communication. A maintenance logbook should be kept next to the instrument if for no other reason than to pass along learnings from previous issues.
  • If thermokinetic measurement is part of your organization’s development SOP, someone on staff should be reasonably familiar with chemical thermodynamics. That can be a chemical engineer, as may often be the case.
  • The users of thermal data are likely to need help with interpretation of the results. Be prepared to offer advice on interpreting the data, taking care not to over-interpret. If you don’t know, say so. It is easier to claw back “I don’t know” than “yeah, go ahead and do that …”.
  • Do not be anxious to singlehandedly bear the weight of responsibility for safety. Safety is a group responsibility.
  • Be curious. How do the insights and learnings from the data translate into best practices? What changes, if any, can the process chemists make to nudge the process for better safety and yields? A credible specialist in RC can make comments or ask questions that lead to better discussions on thermal hazards. Be a fly in the ointment.
  • Never forget that a reaction calorimeter is a blunt instrument for the understanding of a reaction. An RC1 thermogram is a composite of overlapping solution-phase phenomena. Interpretation of results can be greatly refined by pulling timely aliquots for NMR, GC/MS, or HPLC analysis.
  • A database should be constructed to collect and immortalize learnings from all safety work and RC1 learnings fall into that group.

There is the question of who collects and presents the data. An engineer or a chemist? Engineering thermodynamics is a big part of a chemical engineer’s education and skill set. As a plus, an engineer can take thermal data and apply it to scale-up design for safety and sizing of equipment and utilities. You know, the engineering part.

Do not be anxious to singlehandedly bear the weight of responsibility for safety. Alpha males- are you listening??  Safety is a group responsibility that should originate from a healthy group dynamic.

There’s a good argument for a chemist to conduct RC experiments as well. A trained synthesis chemist is qualified to conduct chemical reactions within their organization. That includes sourcing raw materials, handling them, running the reaction, and safely cleaning up the equipment afterwards. But interpreting RC1 data has a large physical chemistry component. In my experience, run of the mill inorganic/organic synthesis people may have seen PChem as an obstacle rather than a focus in their college education. Their skill set is in instrumental analysis like NMR and chromatography, mechanisms, and reaction chemistry. I would recommend having a PhD chemist with a focus on thermo in a leadership role when calorimetry is a key part of a busy process safety environment.

Safety data can be collected and archived all day long. The crucial and often tricky part is how to develop best practices from the data. I would offer that this is inherently a cross-disciplinary problem. Calorimetric data from reaction chemistry can be collected readily, especially with the diverse and excellent instrumentation available today. Adiabatic temperature rise, ΔTad, can be determined by a chemist, but it’s the engineers who understand how the equipment may respond to a given heat release. A smooth and efficient technology transfer from lab to plant happens when good communication skills are used. Yes, SOP’s must be in place for consistency and safety. But the positive effect of individuals who have good social skills and are prone to volunteering information cannot be underestimated.



An automated Windows update disrupted my life today. It swooped in overnight like a winged wraith, did its dark deeds, and flapped quietly back to the dank hole from whence it came. My RC1 data may yet reside unscrambled on the disk drive, but it lies orphaned from the mother iControl application which mockingly professes no recollection of 18 hours of sweet data lovingly produced. The curs in IT can only “tsk, tsk” in their antiseptic way while bobbing pointed heads in faux dismay. Another first-world difficulty uncovered for all to see.


12/20/17. It has been perhaps 6 weeks since CAS has fixed the snag with downloading ACS publications directly from SciFinder. This was a problem because, prior to the SNAFU, the ACS downloads directly from within the SciFinder account would be billed in our monthly statement. Without this feature, every download from the ACS Publications siute, outside the SciFinder account, would then be a separate line item on our in-house expense report with the required circulation for signatures, and absent the contractual discount. So, without the download/billing feature, it was a bigger paper storm and higher document pricing.

Whatever the problem at CAS was, it took some time to fix. Hopefully careers are back on track and all is well.

10/20/17. We have upgraded to Chemical Abstracts Service’s new SciFinder-n which includes PatentPak. After 2 weeks of fairly heavy use I find myself not completely convinced of the marginal value of this upgraded version. Some comments that come to mind-

  • The upgrade resulted in loss of the ability to download ACS publications directly from CAS. This is a glitch that the good folks at CAS are said to be working on. I have no idea as to the extent of this problem across the user base. Obviously ACS publication documents are downloadable from the publication website. The other possibility comes from the official document service of the ACS, FIZ Autodoc. FIZ can provide ACS documents, but for a sizeable premium above an ACS document download fee straight from CAS.
  • All upgrades, good or not good, require the user to adapt to new features. For some navigation, SciFinder-n seems to require fewer clicks and windows to begin a search. The application opens with a Google-like query box allowing the user to input a CASRN, text string, author names, etc., without clicking to a specific search entry window.
  • I use every visit by our CAS rep to lay out what I perceive as weaknesses of SciFinder. So far, no sign that my input even made it into the rental car as they sped away. One big annoyance has been the absence of Boolean searching.  If it can do Boolean searching, I have not found the right syntax or link to use it. This would be welcome.  If I’m wrong here, please leave a comment.
  • I’ve noticed that when looking at a list of references related to a substance query the ‘hits’ are no longer given listing numbers. When you find an abstract to look at more closely and then click back to the list of abstracts, you do not return to the part of the page you clicked away from. I can live with that, but since the document abstracts (see below) are not in a numbered list (1, 2, 3, … n)  you must scroll back and find where you left off by recognition of the text. So unnecessary.

10/24/17. I spoke with a customer service rep at Chemical Abstracts Service (CAS) today. It seems that CAS is in the throes of a software fiasco. The feature that allows a CAS customer to download a pdf document from an ACS publication is presently offline system-wide. This feature allows an account holder to download a document and have the charge added to the monthly billing statement. This greatly simplifies the transaction.

The rep, who was very apologetic, said that as of today it looked like the problem would be fixed in 2 weeks for those using SciFinder Web. No such luck for SciFinder-n however. Evidently the “n” version was released before the ACS document download package was available for it (!!). Luckily a SciFinder-n user can open up the web version. Funny thing is, I have no recollection that our regional representative divulged any of such details during his sales call. Simple sod that I am, my understanding was that “n” was an upgrade encompassing all of the previous web version features. Not quite, it appears. The rep said that the ACS download feature on “n” wouldn’t be available until next year.

Using both the web and the “n” versions side-by-side I must confess that I prefer the web version in many ways. Perhaps due to familiarity. I wonder what others think.




Enroute to other things I ran across an old Gulf R&D patent, US 3294685, titled “Organic compositions containing a metallo cyclopentadienyl”. Sifting through the description my eye caught the interesting content below:

July 1941. A test spray was prepared by dissolving 2.5 grams (3.2 percent) of iron dicyclopentadienyl in ml. of a typical household insecticide base oil. The tests made with this solution employed a dosage of IO-second discharge. An equilibrium :period of 15 seconds followed by an exposure period of 70 seconds, during which the mist was permitted to settle on adult house flies confined in a screen-covered dish, was employed in the tests. The results of the tests showed that of the flies which had been contacted with the base oil containing 3.2 percent by weight of iron dicyclopentadienyl, 53.6 percent were dead after 24 hours. Of theflies which were contacted with the base oil alone, only 13.0 percent were dead after 24 hours. Check flies which were confined for 24 hours without having been contacted with either the base oil or the base oil containing iron dicyclopentadienyl had a death rate of only 0.4 percent. The better than fifty percent mortality of the flies treated with the base oil containing iron dicyclopentadienyl is indicative of the insecticidal properties of naphthas containing a small amount of iron dicyclopentadienyl. Naturally, the amount of metallo cyclopentadienyl used in insecticidal compositions-will vary with the particular compound employed and also depends upon the particular insects for which the spray is intended. The amount of iron dicyclopentadienyl employed in insecticidal compositions intended for use on flies is between about 1.0 and 10.0 percent by weight.

Ya know, a greater than 50 % kill rate seems to be getting a bit sporty for the flies. The ol’ boys at Gulf were studying the suitability of a variety of ferrocene analogs for fuel additive application. What lead them to go from octane enhancement and smoke control to killing flies is not revealed in the patent.

Notice the nomenclature in the patent language. The word ferrocene is not mentioned. Looking at the timeline we see that the Gulf ‘685 patent was filed April 21, 1952, not long after the publication of this curious iron cyclopentadienyl compound by two groups, Kealy & Pauson on 12/15/51, and Miller, Tebboth, and Tremaine on 1/1/52. Though Pauson and Keely published first, an examination of the papers show that Miller, Tebboth, and Tremaine were first to submit- July 11, 1951 vs August 4, 1951 for Pauson and Kealy.

The day before Gulf filed the patent application, April 20, 1952, a groundbreaking paper by Wilkinson, Rosenblum, Whiting, and Woodward was published on the proposed structure of iron bis-cyclopentadienyl. It is reported that the name ferrocene was invented by Mark Whiting, a student of R.B. Woodward and coauthor of the 1952 paper in JACS. The name derives from the ferrous ion and the aromatic (“benzene”) nature of the cyclopentadienyl ligands.

The curious structure was proposed largely on the strength of a single C-H IR band at 3.25 μ. Since all of the C-H bonds appeared to be equivalent, the only structure compatible with the formula, charges and symmetry was the famous η5 (eta five) sandwich structure. Later the word metallocene finds use for this class of substances.

There is disagreement as to some of the details outlined above. An excellent article by Pierre Lazlo and Roald Hoffmann navigates some of the narrower channels in the history of ferrocene. It is well worth the read. Lazlo & Hoffmann suggest that Woodward is thought to have conceived the sandwich structure.

Ferrocene and derivatives would soon prove useful in many areas. A more obscure application is found in the field of rocket propellant additives and function as burn rate stabilizers. In fact, certain ferrocene derivatives appear on the US Munitions List, 22 CFR 121.1, Category V, (f)(4) Ferrocene Derivatives. A good overview of ferrocene and other metallocenes can be found in Wikipedia.

Circling back to the beginning of this piece, the patent application for Gulf ‘685 was filed 4/21/52, only 4 months after the publication on 12/15/51 of the Pauson & Kealy paper and two weeks later the Miller, et al., paper on 1/1/52. In the 4 months between Pauson & Kealy and the Gulf patent filing, two independent groups had published papers reporting the preparation of iron dicyclopentadienyl by different methods, a Harvard group had postulated a structure for the compound using IR data and a novel bonding type, and the Gulf R&D group had produced various analogues for testing as fuel additives. In this short time interval, the first organo-iron compound was taken from a literature source through industrial R&D and a patent application. As a premium, Gulf even determined that it had insecticidal properties. Much happened in a short time.


Wilkinson, Rosenblum, Whiting, and Woodward J. Am. Chem. Soc., 1952, 74 (8), pp 2125–2126. DOI: 10.1021/ja01128a527

Kealy and Pauson, Nature, 168, 1039 (1951). Received Aug. 7, 1951.  DOI: 10.1038/1681039b0

Miller, Tebboth, and Tremaine J. Chem. Soc., 1952,0, 632-635. Received July 11, 1951. DOI: 10.1039/JR9520000632

Laszlo P., Hoffmann R. ACIEE, 2000 Jan; 39(1):123-124.  DOI: 10.1002/(SICI)1521-3773(20000103)39:1<123::AID-ANIE123>3.0.CO;2-Z


One of my job responsibilities is to educate new hires on reactive hazards and the basics of electrostatic discharge safety in the chemical manufacturing environment. The attendees are usually new plant operators with the occasional analytical chemist also in attendance. The educational background for the operators is nearly always a high school diploma with work experience of widely varying duration in non-chemical industries. Since we are far from the regional chemical manufacturing centers in the USA, we rarely encounter applicants from our industrial sector. Commonly the analysts arrive with a BA/BS in chemistry, biochemistry, or even biology sometime in the past.

In their 1 to 2 weeks of introductory training I’m given 1 hour for each of the 2 topics- barely enough time to wedge in important vocabulary let alone develop a command of, well, anything. My approach is to first talk about the difference between hazard and danger with some folksy examples. Then I introduce the general concept of stability using examples boxes on a rising incline. From there, we talk about stability as related to variously truncated inverted conical objects. The notion of instability, meta-stability, and stability are teased out of examples of the tipsiness of inverted cones leading to a change of state under the influence of external forces. This is very concrete and primes the mind to begin to grapple with the abstract notion of substances undergoing change depending on the precariousness of their initial state or the intensity of external influence.

Synthetic chemistry is very much about the careful manipulation of instability in order to produce the sort of change that is desired. Highly stable materials, i.e. sand, are not desirable in a chemical synthesis minimally because they are resistant to alteration. Many reaction steps may be performed and much cost incurred in order to produce features (functional groups) that are sufficiently unstable to undergo the series of desired connections.

After all of the above, the remainder of the hour is spent talking about chemical hazards and how some of them may be passivated by paying attention to the fire triangle. Also the matter of chemical compatibility is introduced as well as the existence of various categories of substances with examples. Of course, this means nothing to them. It’s just a bunch of new words arranged in unfamiliar ways. I’m quite well aware of this, but the purpose is to prime the pump so that when they hear these solvent names and words like acidic, caustic, basic, pH, quench, etc., then can begin the long process of connecting the dots to produce a better picture of their workspace.

The topic of ESD – electrostatic discharge – has its own peculiar challenges. First of all, static charge is invisible, pervasive, and unless you have direct measurements, provides hazards of an unknown risk. To understand ESD hazards, the learner should be exposed to the units describing static charge. These include the Coulomb (C), the volt (Joules/C), the Joule (J), area charge density (µC/m^2), power (Watts = J/sec), the Ohm (Ω = V/A) and the Siemens (S = 1/Ω), and the Ampere (A = C/sec).

Herein lies the real point of this essay. In teaching ESD safety for 4-5 years, I have met perhaps 2 attendees (engineers) out of many dozens who recall having taken coursework relating to basic electricity. I always begin the seminar by taking a poll on who has heard of Ohm’s Law. In reality, I don’t expect electrical proficiency from folks who have not worked in an electrical field. What surprises me is that so few can recall having heard of Ohm’s Law. How is it that we are letting so many people graduate from high school without some course work introducing the very basics of electricity?? This related to one of the most pervasive and influential technologies in our time. I think this is a stunning oversight.

“A’hem, cough cough,” you sputter, “but surely …” –short pause for effect- “… students who have taken high school physics have had instruction in electricity,” you reply with obvious incredulity.

If you had said this you’d be correct. But the educational profile of many factory workers doesn’t seem to include many people who have, in our experience, taken physics in high school. Those from the electrical trades tend not to show up from the temp agency for screening.

So let me end this by asking the mandarins of our school districts why we let students not college bound  graduate without some background in the basics of electricity or electronics? To repeat, this is a stunning oversight, given the extensive use of electrical functions and objects in our lives.




A lot of science is about trying to find the best questions. Because the best questions can lead us to better answers. So, in the spirit of better questions here goes.

By loosening environmental regulations aimed at pollution prevention or remediation, the mandarins reporting to POTUS 45 have apparently made the calculation decided that some resulting uptick in pollution is justified by the jobs created thereby.

Question 1: For any given relaxation in regulations that result in an adverse biological, chemical or physical insult to the environment, what is the limit of tolerable adverse effect?

Question 2: How will the upper limit of acceptable environmental insult be determined?

Question 3: Will the upper limit of acceptable environmental insult be determined before or after the beginning of the adverse effect?

For a given situation there should be some ratio of jobs to acceptable environmental damage.

Example: By relaxing the rules on the release of coal mining waste into a river, X jobs are created and, as a result, Y households are denied potable drinking water. What is an acceptable ratio of X to Y?

Those are enough questions for now. Discuss amongst yourselves.


This post has been updated. Th’ Gaussling, 6/4/16.

If you work with chemicals at the level of chemist in a production environment, chances are at some time in your career you’ll be called upon to help decide when a material is too hazardous to use in manufacture. It can be in regard to raw materials or as the final product. Your organization may have protocols or institutional policies or memories relating to certain classes of substances. Some companies, for instance, will not use diethyl ether in its processes. Others may require hydrocarbon solvents *absolutely* free of BTX. Some companies are so fastidious about worker exposure that the faintest whiff of solvent constitutes a breach. One world class company I know requires R&D chemists to include a process hazard analysis, review, and an inspection for all R&D reactions performed in the hood.  Whatever the company, most have fashioned some kind of boundary as to what is permissible to have on site and what isn’t.

Large chemical companies tend to have large EH&S departments with well established SOP’s and protocols with regard to personal protective equipment (PPE) and the measurement of occupational exposure to substances. Larger companies may have an OSHA attorney on retainer and staff members specializing in regulatory compliance.

One might suppose that smaller chemical companies may not have the depth of hazardous material experience that the larger companies have for many reasons. Smaller companies may have smaller capital equipment and a smaller staff. But smaller companies may have a greater organizational freedom which can lead to a great variety of projects. A great variety of projects often means that a great variety of materials are used on site. As such, a smaller company might very well have considerable expertise in a wide variety of chemical substances and, consequently, a wide variety of hazards.

While a smaller chemical company may have considerable expertise in handling its hazardous materials, it may be lacking in infrastructure for administrative controls and regulatory compliance. A wise CEO watches this aspect as closely as the actual operations.

Whether large or small, eventually a company has to draw the line on what hazards it will bring on site. The chemist has some very sober responsibility in this regard. Through the normal ordeal of process development, the diligent synthesis chemist will find the optimum path from raw material to product. All synthesis consists of the exploitation and management of reactivity. But there is always the “deal with the devil”. In exchange for a useful transformation, properly reactive precursors must be prepared and combined. A mishap with a 1-5 liter reaction on the bench top is messy and possibly an immediate threat to the chemist. But that same reaction in a 50 gallon or 5000 gallon pot can turn into the wrath of God if it runs away. The chemists judgment is the first layer of protection in this regard. All process chemists have to develop judgment with respect to what reagents, solvents, and conditions are feasible. Economics and safety come into play.

A runaway reaction poses several kinds of threats to people, equipment, and the viability of the company. There is the immediate thermokinetic threat stemming from the PV=nRT, meaning that energy can be dumped into PV work leading to the high speed disassembly of your equipment. A prompt release of heat and molecules kicked into the gas phase may or may not be controllable. Especially if the runaway leads to non-condensable gases. A runaway has a mechanical component in addition to the chemical action.

An runaway may cause the reactor contents to be abruptly discharged. Several questions should be answered ahead of time. Where do you want the contents to go and what are you going to do with it once it is there? Catchpots and emergency relief systems are common and resources should be invested there.

A question that the wary chemist must ask is this: What if a cloud of my highly useful though reactive compound gets discharged into the air or onto the ground? Do the benefits of this reagent outweigh the downside costs? Even if a release is not the result of a thermokinetic disaster like a runaway, explosion, or fire, a simple release of some materials may be consequential enough to require the evacuation of a neighborhood. Once your materials have left the site in the form of a cloud or a liquid spill and you make the call to the fire department, you have lost control of the incident. Even if nobody gets hurt or exposed, the ensuing “regulatory compliance explosion” may knock you down.

A chemical process incident can have mechanical consequences, chemical release issues, and the matter of fire. Substances that are pyrophoric have automatic ignition problems that may be surprisingly easy to deal with, especially if they are liquid. Liquid transfer systems can be inerted easily and pyrophoric liquids can be transferred airlessly and safely. Pyrophoric solids are another matter. There  are few generalizations I can make about pyrophoric solids. Inert solids pose enough handling issues without having the added complication of air/water sensitivity. All I can say about pyrophoric solids- waste or finished product- is that you will need solids handling equipment, a big supply of LN2 and procedures for passivating hot filter cakes. Production glove boxes and Aurora filters are particularly useful. Also required is a space on the plant site where you can open up a container and let the contents burn if needed. If air gets into a container of pyrophoric solids, it’ll begin to get hot. That is when you need to have an open spot where it can smolder or ignite harmlessly and not bring the facility down. Crowded industrial parks are a bad place for such material handling.

When designing a chemical handling space, it is important to think about what happens in a fire. Flammable liquids are under the constant influence of gravity and will run to the low point on a floor. The question you must to ask beforehand is this: Where do I want the burning liquid to go? There are good choices and poor choices. Preferably a stream of burning or flammable liquid should run away from evacuation pathways and exits as well as anywhere other hazardous materials or combustibles may be contained. To some extent this is moot because indoor spaces should be covered by a fire suppression system. But outdoor spaces may be problematic in regard to crowding of a tank farm and drums and cylinders.

Burning pools of organic liquids radiate considerable energy per sq ft per sec (power in Watts). The temperature of nearby objects will rise rapidly to the flash point and the ceiling spaces will accumulate smoke and hot gas. Drums and cylinders filled with flammable liquids or gases will eventually overpressure and release their contents adding to the mayhem. The release can be in the form of a BLEVE or a flood of flammable liquid leading to a widespread pool fire.

There are resoures available to quantitate the risks of such releases. The American Institute of Chemical Engineers (AIChE) is well organized and provides much literature on the topic of chemical plant safety. In particular I am thinking of Dow’s Chemical Exposure Index Guide, 1994, 1st Edition, AIChE, ISBN 0-8169-0647-5.  This handbook takes the reader through calculations aimed at estimating the risk and likelihood of chemical releases.

Also available is Dow’s Fire & Explosion Index and Hazard Classification Guide, 1994, Seventh Edition, AIChE, ISBN 978-0-8169-0623-9.  This handbook supports the use of a quantitative risk analysis chart for the use of a risk and hazard index for generating numbers associated with process activities for cost/benefit analysis. It is well worth the addition to your library

Such flammable liquid scenarios can begin many ways.  Forklift and maintenance operations are particularly rich in opportunity for a fire. The physical location of flammable liquid storage must be well thought out. Ideally a warehouse fire should not be allowed to spread to capital equipment locations. This helps to keep workers out of harms way and contains the magnitude of the financial disaster as well.  Since most chemical plants seem to grow organically over time, unfortunate choices are usually made in regard to incident propagation.

One type of propagation incident can be ameliorated through the clever use of architecture. I am aware of one tragic incident where an explosion occurred in a processing space of a facility that had grown over the years by the addition of contiguous manufacturing and warehouse spaces. A rabbit’s warren of interconnected rooms and hallways accumulated over time. At the moment of the reactor explosion, the room and adjacent spaces were badly damaged by the blast overpressure as you’d expect. However, since the building was interconnected the overpressure propagated throughout many other distant spaces and delivered considerable structural damage to the facility. Overhead doors were bent outwards and windows and man doors blown out. Extensive damage may have been avoided by the simple expedient of providing open air walkways to separated buildings rather than enclosed hallways between adjoining areas. Of course, the benefit of this depends on the who, what, where, when, and how, but eliminating pathways for a blast wave is a cheap and easy way to start.

When is a substance just too hazardous? This is fundamentally a business or policy decision. Ultimately, it is the responsibility of the organizational leadership to draw the line on the risks that are deemed acceptable. It is the ethical responsibility of those knowledgeable and experienced with the proposed chemistries to combine information with pragmatics to provide persuasive feedback to the decision makers in charge.

There are plants that routinely manufacture nitroglycerine, phosgene, chlorine, phosphine and HCN. Workers spend their careers in these places.  Most risks can be abated by properly engineered processing and packaging. It really comes down to personal choice. Is that ammonium perchlorate plant that just offered me a job operated safely? These reactive and/or energetic materials all have properties that lead to demand for their use. Somebody is going to supply that demand. We chemists have to look inward and then act with our eyes wide open and our heads on a swivel. Myself? I wouldn’t work in a nitroglycerine factory, but I’m glad that someone does.’

[Added 6/4/16 by Th’ Gaussling] I happened to go back to this post and in doing so read a comment by “Bob”, which you can see in the comment section below. Here is a copy

“I actually believe that as a society should keep the safety rules relaxed a bit in academia. Academia, for better or worse, is our national chemical research institution”

So underpaid grad students, postdocs and staff working at  a univeristy are less human, and less deserving of safety than their for profit brethren?

That’s diabolical Mr. Gaussling. Pure evil incarnate. For whose gain do you sacrifice their lives?

I want to address this now better than I did back then. To Bob I say this: Everyone has a right to a safe workplace. Academic institutions as well as industrial operations must use best practices in regard to worker safety. This is axiomatic. Plainly I did not articulate my contention as well as I could have. I will do so now.

We have to assume that junior chemists are likely grow to be senior chemists in an organization. The role of a senior chemist in industry for example, may be quite varied through her/his career. A senior chemist who has stayed in the technical environment will almost unavoidably have been confronted with a large variety of questions in regard to circumstances and outcomes relating to hazardous materials and tricky reactions. Moreover, a senior chemist is likely to have been promoted to a level that also involves supervision, the drafting of SOPs, work instructions, MSDS documents, emergency planning, laboratory design, etc.

In my view, a senior chemist as described above has an ethical and moral responsibility to coworkers, plant operators, material handlers, and customers to oversee chemical safety. A chemist at any level has a responsibility to make known to all involved what dangerous circumstance might arise with any given chemical operation. Either in relation to the hazardous properties of substances that may be released in mishandling, or in regard to hazardous processing conditions that can lead to danger.

I’ve used the word hazard(ous) and the word danger(ous). We need some clarity on this. If you Google the words and stop with the dictionary definitions you will be left with the shallow notion that they are synonyms. If you dig deeper, say at the website of the Canadian Centre for Occupational Health and Safety (OSH), you will find a definition of “hazard” that I find particularly useful. To wit:

A hazard is any source of potential damage, harm or adverse health effects on something or someone under certain conditions at work. [italics mine]

The same fuzziness in definition exists for the word danger(ous) as well. A definition I prefer is below:

A dangerous occurrence is an unplanned and undesired occurrence (incident) which has the potential to cause injury and which may or may not cause damage to property, equipment or the environment. [italics mine]

This definition is borrowed from the University College Cork, Ireland (UCC). I believe this is a good definition and it readily sits apart from the definition of hazard above.

The key difference is that a hazard is any source of potential of damage … under certain conditions.. whereas danger is a condition brought on by an unplanned or undesired occurrence. Next, lets consider these terms in the context of chemistry.

On the shelf in the fire cabinet is a glass bottle of phosphorus oxychloride, properly sealed and segregated. As the POCl3 sits on the shelf in the cabinet, I would argue that it is only hazardous. If, however, you pick up the bottle and in walking to the fume hood drop it causing it to break and spill the contents in the open, you’ve caused a dangerous situation. It’s an imminent threat to health and safety.

Conversely, let’s say that you carried the bottle to the hood, used it, then returned it to storage without incident. In the reaction the POCl3 is consumed and in the workup the residual acid chloride is quenched by water. Congratulations! You have taken a hazardous material, used it safely, passivated the actives during workup, and eliminated at least the acute hazard relating to POCl3.

In the first situation, a hazardous material was mishandled and became dangerous. In the second situation, the hazardous material was handled properly, consumed, and residuals passivated. In this case a hazardous material was used safely and to positive effect.

Seem trivial? Well, it’s not. This difference in meaning leads to a confusion that is especially acute among the non-chemist population. But my point leads to the question of how students are taught to use hazardous materials.

I spoke of relaxing safety requirements in academia. An example of such a thing might be the use of diethyl ether. This useful solvent is banned outright in some chemical manufacturing operations across the country owing to the flammability. Even in their R&D labs. This is corporate policy handed down by those responsible for risk management, not scientists. In some industrial labs, woe is he who has an unexpected occurrence like a boil-over or a spill.

I believe that Et2O should remain in academic research labs for both the research value and for the development of valuable lab experience by students and postdocs.

You learn to handle hazardous materials by having the opportunity to handle hazardous materials.

Ether is only a simple example of what I’m trying to communicate. In order for chemists to graduate as experienced scientists with working familiarity in the properties of substances, they must have experience handling and using a large variety of substances, many of which may be substantially hazardous. And by hazardous I mean much more than just toxic. A substance may have a reactive hazard aspect that is a large part of it’s utility.  To safely handle substances that pose a reactive hazard, a chemist needs to have experience in using it. And killing it. The chemist must try to gauge the level of reactivity and modify the use of the substance to use it safely. If you’ve made or used a Grignard reagent you know what I mean. Expertise in laboratory chemistry only comes through direct experience.

Hazardous reactive materials do useful things under reasonable conditions. Non-hazardous, unreactive materials find great utility in road and bridge construction.

If we regulate out all of the risk by eliminating hazardous materials in academic chemistry, what kind of scientists and future captains of industry are we producing? What we can do is to put layers of administrative and engineering protection in the space where the hazardous transitions to the dangerous.  Academic laboratory safety is promoted by close supervision by experienced people. Limits on the amount of flammables in a lab space, proper syringe use, safe quenching of reactive residues, proper use of pressurized equipment, and a basic assessment of reactive hazards present in an experiment will go a long way to improving academic lab safety. Experienced people usually have a trail of mistakes and mishaps behind them. If we corporatize the academic research experience to a zero risk condition, we may kill the goose that lays the golden egg.




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