Chemical Incident Misreporting Reporting – 10-18-22

I frequently have problems with reporting about chemical incidents and more than a little of that is my fault expecting various folks in the reporting process to be trained chemists. Looking at news reports, it is frequently difficult to tell if the misunderstanding is due to incorrect terminology being used by first responders or reporters trying to read between the lines, but usually I can figure out what was probably happening. Today, however, I came across a truly bizarre description of a chemical incident that occurred this weekend at a medical lab in Vancouver, WA.

The following description is one-third of an article I found today on Columbian.com:

“After a chlorine gas spill at the company, bleach was used in an attempt to clean up the mess. The chemical reaction between the two led to off-gassing. The building was evacuated, but four employees showed symptoms of exposure, including red eyes.”

First problem, if there had been a chlorine gas spill, there would be no one in the building until someone verified that there were no chlorine gas fumes in the building. So, there would be no chlorine remaining to react with the bleach. Second, since this is a medical lab facility, it would not be unusual for facility cleanup to include the use of bleach, but the personnel would be familiar with the chlorine odor associated with that cleaning technique. Third, if there had been serious outgassing from the use of bleach (and that could occur if the bleach came in contact with any number of chemicals, including many cleaning materials) there would have been much more serious problems than just red eyes. Finally, I am having problems figuring out what a medial testing lab would be doing with chlorine gas cylinders on site.

What I suspect happened was that there was an incident at the lab while cleaning was taking place. Either there was an unexpected reaction between a chlorine bleach cleaner and some other chemical at the lab that outgassed a small amount of chlorine gas, or there was a large amount of bleach spilled (probably the later) which includes some minor chlorine outgassing as a matter of course (bleach slowly decomposes to chlorine gas and water at room temperature). In any case, a bleach incident occurred that was significant enough that the emergency services were involved. The spill was cleaned up, the building aired out, and four people were taken to the hospital for burning in the eyes (a common exposure symptom for very low levels of chlorine gas exposure.

To be fair to the reporter who prepared this article (and all local news reporters covering the police/fire beat) the reporter almost certainly was never given access to the scene and probably never talked to a representative from the facility (facility owners are trained to give prepared statements and not talk to the press). So, the information probably came from the fire person in charge at the scene while incident cleanup was taking place. Bleach (sodium hypochlorite) is commonly referred to as ‘chlorine bleach’ and even ‘chlorine’ and this causes no end of confusion. If we could just get everyone to take a first-year chemistry course….

One final note, if any of the four treated individuals was admitted to the hospital for observation, this would have been a reportable accident under the CSB's Accidental Release Reporting Rule.

Chlorine Release at Recycling Center

Earlier this week there was a chlorine gas release from a 1-ton cylinder that was being processed for recycling at a facility in Spokane, WA. As we expect to see in an event of this sort initial news reports (here, here, here, and here) are somewhat contradictory and more than a little confused. It is clear, however, that a number of people are in local hospitals in serious condition from complications due to chlorine inhalation. No deaths have been reported.

What we appear to know at this point is that a chlorine cylinder was delivered to the facility for recycling. The facility expects the offeror of the cylinder to ensure that it is empty before it is delivered to the facility. There is probably no reasonably safe way to the facility to test this for themselves.

At some point in the recycling process (in a crusher?) the cylinder integrity was compromised and the contents were released to the atmosphere inside a building on site. The resulting gas cloud was not confined to the building and off-site personnel were affected. This argues that there was a substantial amount of chlorine in the cylinder, not just residues.

At this point in the investigative process there has been no information released about who delivered the cylinder to the facility. Since these cylinders are re-useable and fairly expensive, I find it difficult (but certainly not impossible) to believe that the rightful owner of the cylinder (a chemical company or chemical distributor) sent an in-service cylinder to be recycled. These things are very expensive and have a long service life that is used to amortize the initial cost of the cylinder.

Cylinders that no longer meet the PHMSA criteria for use would certainly be recycled after they were emptied and cleaned (these are big heavy metal cylinders and worth a significant amount of money as scrap metal). The determination that they no longer met PHMSA standards would only be done after PHMSA approved testing which has to be done on an empty and cleaned cylinder. This is why it is unlikely to have come from the rightful owner.

This leads me to believe that the cylinder may have been stolen for its scrap metal value by a thief that did not know that the cylinder still had a significant amount of chlorine still inside or didn’t care. In either case it should be fairly easy to track the cylinder back to the facility from which it was stolen. These cylinders are serial numbered and even if the number were removed there should be a VERY small number of these cylinders stolen.

In any case this situation does show that it is reasonably possible for someone to get their hands on a significant amount of chlorine in this country. That combined with the current use of chlorine based improvised munitions in the Middle East by the Islamic State forces raises the specter of similar munitions being used in terror attacks in here at home. This is not a real high threat as it isn’t an attack method that could easily be used by your local internet-recruited IS wannabes, but it could be used by someone trained by the IS in Syria or Iraq.

It will be interesting to see if we ever hear about where this particular cylinder actually came from.

Chemical Incidents Come in All Sizes

Chemical related incidents come in all sizes and locations. It is not just accidents at chemical manufacturing facilities or transportation centers that can result in emergency services responding to chemical incidents. This was seen last week in a chemical response incident in a small town in Pennsylvania last week. See the news story here, here, and here.

The Incident

Residents in a residential area complained about the smell of chlorine (most familiar to people as the smell of bleach). Emergency responders located the source of the leaking chlorine gas, a cylinder inspecting and refurbishing shop located in an older residential area. The tank was sealed and the building ventilated. Local residents were told to shelter in place until the chlorine gas dissipated.

Four people were taken to the hospital ‘for observation’ according to news reports. It is not clear if they were employees at the company (most likely to have significant exposure) or nearby residents. There are no follow-up news reports so they were probably released after their observation period was completed with minimal complications.

Chlorine

Chlorine is typically shipped as a liquid in pressurized cylinders. When that pressure is released the liquid evaporates into a gas that forms a heavy, yellow-green vapor cloud. Chlorine is a toxic inhalation hazard (TIH) chemical that has been successfully used as a chemical weapon in WW I. The allowable exposure limit (OSHA PEL) is 1 ppm. It is detectable by its characteristic odor by most people at 0.32 ppm. The concentration of most concern is the immediately dangerous to life and health (IDLH) which is 1000 ppm. According to NIOSH exposure between the PEL and IDLG may lead to the following symptoms:

Burning of eyes, nose, mouth; lacrimation (discharge of tears), rhinorrhea (discharge of thin nasal mucus); cough, choking, substernal (occurring beneath the sternum) pain; nausea, vomiting; headache, dizziness; syncope; pulmonary edema; pneumonitis; hypoxemia (reduced O₂ in the blood); and dermatitis.

People with other existing respiratory problems will exhibit symptoms at lower exposure levels than more healthy people.

The Business

The company has been in operation since 1946 (probably in the same location). They take DOT rated cylinders used for the transport of hazardous gasses and liquids and conduct the periodic safety inspections that PHMSA requires for such cylinders. The testing requires that the tanks be emptied, visually inspected and then filled with water. The tanks are then pressurized and observed for signs of leaks and the expansion of the tank is measured. The tanks that pass are then marked and recertified for hazmat service in accordance with PHMSA regulations.

The company’s web site would seem to indicate that the majority of the tanks tested at the site were propane tanks. The web site does indicate that other types of tanks are also tested, including ‘low pressure’ (<900 amounts="" and="" are="" areas="" at="" chlorine="" disinfection.="" for="" o:p="" of="" other="" parks="" plants="" psi="" relatively="" small="" tanks.="" tanks="" that="" these="" treatment="" types="" typically="" use="" used="" usually="" water="">

The web site indicates that there is a service fee for emptying propane tanks. There is no such fee listed for emptying chlorine cylinders so it would appear that the company required those tanks to be delivered empty. This would not be unusual for a small shop that did not handle chlorine for other reasons.

What May Have Happened

Unless the investigation by various government agencies (principally state EPA and OSHA) reveals unsafe practices that result in fines, the public will probably never hear the details of what happened at this facility. Based upon news reports, I can come up with a reasonable scenario for what might have happened.

The operator opening the cylinder would have been wearing minimal personal protective equipment (hopefully a half-face cartridge respirator, chemical goggles, a chemical jacket and industrial rubber gloves), expecting the cylinder to be empty. When the tank began to off-gas a significant amount of chlorine the operator would have been instructed to sound the local alarm and evacuate the immediate area.

Since the facility did not apparently expect to actually handle chlorine gas on site, there would probably not be ventilation systems in place to scrub the chlorine from the local atmosphere. Ideally the facility employees would move to an assembly area upwind of the facility and the local fire department would be notified. A properly equipped Hazmat Team would respond, seal the tank, ventilate the area, and conduct atmospheric testing until the area was cleared.

From the news reports it does not seem that the notification of the local emergency responders was made by the facility. This may have been due to confusion on the site, or it may indicate that smaller chlorine releases were normal enough that there was not an apparent need to report this incident.

If the facility were routinely handling cylinders with significant residues of liquid chlorine in the cylinders, I would expect the facility to have a lot more complex system in place for opening those cylinders including a local ventilation system equipped to scrub the chlorine gas from the atmosphere in the event of a release. I would define ‘significant residues’ as any visible liquid, but the EPA only requires reporting of spills over 10 lbs, so arguments could be made for any quantity between those limits.

Emergency Services

Chlorine is a widely used hazardous chemical. As such, urban and suburban fire departments should have at least minimal training in handling chlorine related incidents. While the incidents of most concern will normally be found at manufacturing facilities and along transportation (chlorine is routinely shipped by rail and truck) routes, smaller incidents are not unusual.

It certainly appears from the news reports that the responders in this case knew what they were doing and responded effectively.