Tear gas – more than a crying matter
Yesterday, Monday the 19th of January 2015, the police fired tear gas at school children ……. the kids were supposed to cry and run as far away as they could from the precious wall belonging to a more deserving citizen. I shall not rant about the ridiculous cruelty and injustice of this. I shall focus on the pictures that carried the day – on the front cover of the Nation today is a child who fainted during the attack.
Can tear gas make you faint?
There is not a lot of literature out there about tear gas but there are some interesting papers. A case report published by Park and colleagues from Korea investigates the health hazard of the tear gas mixture. They measured quantities in a controlled setting, which would reflect actual riot conditions. The gas disperses in the air fast, but in large quantities it is not just the eye irritation we should worry about.
The paper published in 2010 informs us that tear gas comprises of chemicals that stimulate the corneal nerves in the eyes to cause tearing. As you may be eager to know the names of the chemicals, here they are:
1-The most common is o-chlorobenzylidenemalononitrile– yup, let’s call it ‘CS’ as Park and colleagues as well as almost any other sane person would
2- The other is Phenacyl chloride – much better that, but let’s call it CN
I was a below average student in Chemistry in high school and worked really hard to get to average – therefore I will not break down the matter further, because I can’t, but I digress…..
Now in most tear-gas formulations, CS (I am sure you would rather I called it this) is mixed with another chemical called Methylene Chloride – a chemical that is found in paint strippers and degreasers. Methylene Chloride dissolves CS at room temperature making it a very convenient solvent for the tear gas. Compared to other solvents Methylene Chloride has fairly low toxicity – in SMALL volumes. But breathed in large quantities, Methylene Chloride, depresses the central nervous system – because the human body breaks it down to carbon monoxide.
If your central nervous system is depressed what happens? Headaches, nausea, dizziness, clumsiness, drowsiness – effects similar to those of drinking alcohol. At high levels it can cause unconsciousness and death. I do not imagine that the police at Langata primary school stopped to consider the dose to use in children and shot out the same quantities they do for adults. No wonder children fainted at the scene. The children were also fortunate to have people get them from the scene fast enough to avoid them getting trampled on or breathing even more poison fumes.
But there is more to teargas – it’s not just the chemicals you should be wary of.
A paper by Clarot and others published in 2003 in the Forensic Science International Journal titled ‘Lethal head injury due to tear-gas cartridge gunshots’, gives you an idea. Although the gas itself only causes acute irritation, the blast from the weapon is not just gas, but has 3 components: the propellant, the wadding and the chemical agent. The propellant generates the charge to propel the tear gas from the cartridge. The cartridge containing the tear-gas can be made of rubber or other material is also part of the blast. The tear-gas comes as a fine powder which quickly becomes a gas in contact with air. In close contact the powder may actually get into the body and become gaseous within the tissues, depending on which organ is affected, the outcome can be fatal.
If a fellow fires a tear gas weapon within a centimetre from you – Clarot says, ‘the gas jet alone generated by a tear-gas cartridge possesses the characteristics of a missile fired at close range’. The paper reports an adult suicide from such a weapon. Tear gas weapons really are not just a crying matter.
It is very likely that the tear-gas attack at Langata primary school will not be repeated in Kenya again I believe the police have learned their lesson – I am a hopeful citizen. But the bringing down of walls by students will. There are too many greedy adults in this country and all of us who went through public primary schools know that across the land, our school lands were grabbed in the 80’s and 90’s without shame. How the police will handle future demonstrations will I hope, be as a result of exerting their grey matter and not brute force.