Friday, February 23, 2007

Chlorine: Don't Call it a Comeback

Cross-posted at Danger Room.

Chlorine is to WMD as Run/DMC is to rap: old school. The OG of WMD is making a comeback on the mean streets of Baghdad, and it isn’t good. Fellow Danger Room contributor Jason Sigger has pointed out the media hype that has followed these attacks. And he’s right so far. Chlorine is more hype than hurt, but it does at and ugly new facet to the war. So let’s put on our thinking hats and learn a little about our nasty little friend chlorine.

It’s everywhere and sometimes in large quantities. One of its primary uses is water purification so everywhere that there is water production, there is chlorine. Good news: in the US, Hazmat teams spend a lot of time dealing with it and training for releases. Lugging around a chlorine kit in a Level A suit is not fun (trust me), but dealing with chlorine releases is part of the curriculum for all Hazmat Technician training. There are releases, but fire departments with hazmat teams are ready.

This is not to say that these releases aren’t significant emotional events. According to the 2004 Emergency Response Guide (which every concerned citizen should know and love) the impact of chlorine release is as follows:

Small Spills

Large Spills


Protect Downwind:


Protect Downwind:

30 meters (100 feet)



240 meters or 800 feet



.2 km or

.2 miles

1.2 km or

.8 miles

2.4 km or 1.5 miles

7.4 km or 4.6 miles

Isolate means block off the area and have people in the hotzone protect or shelter in place. Protect downwind has you either evacuating the population or protecting them in place. (And you thought duct tape and plastic was one big joke.) The ERG distances are a rough estimate intended as a starting point in an emergency. Weather and terrain impact what the gas will do.

A large spill in an urban area is bad news. Chlorine gas is heavier than air so it tends to hug the terrain in a vapor cloud, especially at night. Given the right weather conditions, it might take hours for a cloud to dissipate as it moves downwind or downhill. In the US, communities are prepared for this, but is the Baghdad Fire Department Hazmat team ready? I sure hope so.

Chlorine attacks the body in two ways: 1) as an inhalation hazard where it produces choking, respiratory distress, and at high concentrations our good friend pulmonary edema. 2) as a contact hazard where it burns eyes, mucous membranes, and even moist skin where it reacts with moisture forming hydrochloric acid.

According to my NIOSH pocket guide (another great document BTW), Chlorine is Immediately Dangerous to Life and Health at 10 parts per million. Air purifying respirators (gas masks) are recommended for escape use at concentrations up to 5 parts per million with the appropriate filter. The odor threshold for chlorine is about .3 parts per million. In other words, if you smell it, you have plenty of time to mask up and get the hell out, but in order to enter the hotzone and take care of business, you need to be wearing a self contained breathing apparatus and a fully encapsulated chemical protective garment. Level A all the way.

At the smell threshold, people might begin feeling other effects such as burning eyes and nose. People are chemo-phobic so even those who aren’t in an area of dangerous concentration will be worried. And the worried well often find their way to hospitals where they can overwhelm even the best emergency rooms.

So chlorine might not be a weapon of mass destruction, but it sure as hell is a weapon of mass effect. A large release done the right way can send a city reeling. The use of chlorine as a weapon indicates to me that the insurgents are adapting and upping the ante. Imagine living in a city where there are explosions, shootings, and mayhem every day of the week. Now, add poison gas to the mixture. Life in Baghdad sucks worse everyday.

If I were a planner in Baghdad right now, I’d get smart on hazmat in a hurry because I’m guessing that this is just the beginning.

Notes: I debated about writing about this for fear of giving the insurgents information that they can use. They have the internets too. Therefore, I have omitted any reference to how US Forces deal with this threat. All the information that I have used is available in open source. I hope any of the bad guys messing with this stuff die painfully in a green cloud of choking death, but that’s just me.

Also, Dick Destiny has in interesting post on this. He makes some good points about the domestic panic over chemicals. Like I said, people are chemo-phobic. In the US, we’d be better served with a robust education program about sheltering in place than spending billions on protecting chemicals that are basically everywhere. Communities near chemical plants have been doing this effectively for years. Paging Wally Wise.

Finally, the Chlorine Institute is a great resource for responders dealing with this substance. Hint, hint for all you Chemical Officers in the box.

Labels: , ,