Riot control agents- toxicology. Characteristics. Medical activities
Written by Anam Hussain
General characteristics:
- Riot control agents are irritant chemical agents that belong to a class of agents collectively known as tear gas
- Belong to incapacitating toxic materials
- Used mainly by law enforcement forces
- Include: pepper spray, lachrymators, Sternitis
- Lachrymators:
- Solid crystal compounds
- Odourless
- Most often used are CN and CS
- CS is a white crystalline solid, burnt to form colourless gas- insoluble in water and ethanol
- At room temperature is found in solid form. High dispersal techniques are required to be used by police
Pathophysiology:
- Tear gases are reflex toxic compounds
- Rapidly reach high concentrations in mucous membranes of upper respiratory tract and eyes
- This causes severe irritation of corresponding nerve endings to such structures
- Intense impulses transmitted via nerve endings of olfactory and Vagus nerves to CNS
- Triggers reflex responses such as hyperstimulation of normal functions
- Manifested by uncontrollable sneezing and lacrimation
Clinical signs and symptoms
- Respiratory signs and symptoms:
- Chest tightness, cough
- Cyanosis, dyspnoea
- Hoarseness, hypoxemia
- Tachypnoea, non-cardiogenic pulmonary oedema
- Sensation of suffocation, wheezing
- Skin and mucous membrane symptoms
- Skin: redness, pain, blistering and burns
- Ocular: lacrimation, irritation, redness, blurred vision, corneal burns
- Nasal: rhinorrhoea, burning, irritation, oedema
- Oropharynx: sore throat, hoarseness, dysphagia, salivation, oral burns and irritation
Differential diagnosis must be done with intoxication by: ammonia, chlorine, HCL, H₂S, Phosgene
Medical Activities
- In case of use of tear gases, protection of eyes, skin and respiratory tract is required.
- Any wet fabric is a plausible measure
- For those affected in AOD, best to start with aiding inhalation of antismoke mixture
- After leaving AOD perform decontamination via rinsing mouth and eyes with water or 2% sodium bicarbonate solution
- Analgesics administrated for eyestrain
- General toxicity requires administration of antidote called unitiol
- Most effective for removing pepper spray from skin is application of baby shampoo
- Wipes for decontamination are available
- Antidotes: Capsazepine, Ruthenium red are effective in treatment of pepper spray intoxication