Extraction Products Featured

When Things Go Wrong in the Extraction Lab

Written by Saman Razani

As extraction equipment operators and laboratory technicians, our work can often be dangerous and complex. From hazardous processes using volatile chemicals, to glassware exploding under pressure — safety is always of utmost priority and should be taken very seriously. Accidents can happen in the lab and you have to be ready for that. Lab technicians and extraction equipment operators should ensure they are always prepared with the proper personal protective equipment (PPE) for the tasks they are performing and that they have read the safety data sheets (SDS) provided by chemical manufacturers for the solvents or chemicals in use or on-site. Everyone out there reading this may not have a particular horror story that they can pick as memorable, but I assure you, the ones we will discuss here will bring back nightmarish memories for most.

When things go wrong in the lab, it’s usually a result of the following:

  • Manufacturer or engineering flaw in failing equipment
  • Worn-out equipment
  • Negligent operators not following standard operating procedures (SOPs) and equipment use instructions, and ignoring operating specifications of equipment
  • Negligent trainers that fail to execute proper training or produce sufficient SOPs for the staff operating the equipment or conducting a process

General lab failures can consist of varying degrees of disaster, from using incompatible heat transfer fluids in an expensive, low temperature chiller; to using incompatible tubing or gasket materials with certain solvents in hazardous chemical refinement processes; or even cleaning your instrument components with certain solvents. Mostly though, they involve carelessness — carelessness in reading or researching critical information surrounding equipment handling, in reading equipment specification sheets and operating within those specifications, or just general clumsiness leading to everyone’s favorite — broken glassware. Whether it be a dropped glass vessel with thousands of dollars’ worth of product in it that gets ruined as a result, or just a really expensive, custom glass apparatus or instrument component that gets broken — it typically happens at the most inopportune moment, costs a literal arm and leg, and takes weeks to be shipped to you from an original equipment manufacturer (OEM).

Other lab failures that occur in an extraction/manufacturing setting are caused by mechanical or electrical component malfunction, like a critical temperature sensor failure that can cause a dangerous increase in vessel pressure during a flammable gas extraction. Or perhaps a diffusion pump being started up improperly on a large wiped film evaporator (WFE), exposing the silicone oil, which is heated and creates the high-speed fluid jet that guides molecules through the system at high velocity. The oil can be exposed to oxygen causing oxidation of the silicone, or in some cases, even decomposition in the pump, leaving behind carbon deposits and rendering the system completely useless. Or similarly, a new turbo molecular pump being shut down incorrectly, seizing the stator rod and turbines, rendering a $6,000-$10,000 piece of equipment completely useless.

Even though broken glass apparatuses can really put a damper on a production environment, nothing quite encapsulates the horror of a fire breaking out in the lab — especially a preventable fire.

Safety hazards and dangerous lab practices are tinder for a catastrophic accident or fire — both literally and figuratively. One example of a dangerous laboratory practice/protocol would be using any electrically operated equipment, but in this case an electrically operated vacuum pump to pull vacuum on a closed-loop extraction system (CLS) containing flammable, condensable vapors, (i.e., hydrocarbons like butane and propane). It is extremely rare to see ancillary equipment that doesn’t meet the new standard for this volatile work. In this case, it was inexperience and a lack of fundamental understanding and training on the safe operation of the equipment.

This particular incident occurred in a California lab which was conducting flammable gas extraction operations in a code-conforming facility, in a rated enclosure for compliant C1D1 operation, with mostly rated equipment minus one small piece of equipment that had a very large impact in this case. After many successful runs, the operator commenced his normal protocol for preparing the extraction system, pre-operation. Like any extraction system, flammable gas extraction operations require the closed-loop extraction system to operate under reduced atmosphere, or under vacuum (for all you non-lab-rats). This means that the operator needs to reassemble and connect all extraction system parts and components and then physically connect the system to a vacuum pump via a vacuum line located in the hazardous control area.

Now, in most labs, this is a very well-known potentially hazardous operation, one that requires the use of rated/conforming support equipment such as a pneumatically driven vacuum pump, also known as a Venturi style pump, even though the extraction system may be seemingly free of any remaining flammable gas. This device works by creating a static pressure drop via compressed air flow originating from an oil-free scroll compressor. Anyhow, this particular operator chose to use an electrically powered vacuum pump to perform the task described.

Upon reassembly, the operator failed to realize that the rated connection hoses, like the one going right to the vacuum line, were in fact still full of a butane/propane vapor/gas mixture. When the operator connected the vapor-laden hose to the electric vacuum pump and the flammable condensable vapors hit the electrically driven motor, static electricity most likely ignited the condensable vapors, and a flame sparked in the vacuum pump compression chamber that erupted outside of the control area where the pump was located, setting the pump and nearby infrastructure ablaze. The fire’s origin was small but created a large fire that spread and kept burning. After a few seconds, the fire sprinklers went off, and since this fire started outside of the control area and in a completely open space in a larger warehouse, the entire 15,000 sq ft facility’s emergency sprinklers kicked on and the water just started pouring. After days of clean up as well as removing building materials irreparably damaged by water to prevent the growth of mold, it was obvious that the management had failed to ensure their business’ and their staff’s safety, and they are lucky that no individual was hurt in the accident. After everything was said and done, the fire could have been prevented with the use of a $120.00 tool and an air compressor which they had in the building… insert face into palm.

Other common examples of preventable lab failures are usually caused by not maintaining parts and components for equipment. Most lab equipment comes with some form of consumable components, like bearings, seals, nuts and bolts, refrigerant, lubricant, etc. that needs to be maintained. These are all contributing factors in preventable incidents that unfortunately happen all too often and that have recently, within the last year, claimed the life of a fellow industry peer and extraction operator in Canada. Perform maintenance checks on your equipment!

Something that has always failed to be realized is the concept of preventative maintenance. As humans, we tend to stick to the old saying “don’t fix it if it’s not broken.” This only applies if your parts or components never get worn out, and unfortunately, every component we use in the lab uses consumables that have a shelf life.

Waiting until the last minute to do things always ends in disaster. Another common lab failure occurs from the over-torquing and stripping of brass nuts from a tri-clamp assembly, holding back hundreds if not thousands of pounds of pressure in the extraction system. This almost exclusively occurs after the brass hardware has taken constant abuse over long-term use or has been over-tightened by an uninformed or improperly trained operator too many times, and the threads on the brass nut are now stripped. The use of proper equipment as well as constant tightening and loosening of these highly used parts are essential to life safety. I’ve seen the aftermath of a simple brass nut failure and thankfully no one was hurt. But to me, it’s always been strange that a simple torque wrench can usually be the factor in avoiding these traumatic experiences from happening in the first place. Also, directions people — remember if your component specifically states its rating for “in/lbs.” and your tool is calibrated in “ft/lbs.”, avoid being the fool, and use the correct tool.

In the end, problems or challenges will always present themselves in the lab. A good operator will fix the problem and keep going; a great operator will be able to solve the problem and prevent future problems from occurring. Find a great operator and avoid the issues we covered above.

About the author

Saman Razani