The guns could be potentially lethal if used on people with respiratory illness, a doctor told Apple Daily.
Piexon, a Swiss manufacturer of less-lethal munitions that specializes in liquid irritant launchers, is reportedly selling its most advanced and expensive model to the city's police force.
The Piexon JPX6 Jet Protector fires a patented Piexol 400kS irritant, which is described as "a cayenne pepper extract and the most potent pepper-based irritant on the market", according to Piexon. Each cartridge carries 10ml of Piexol, meaning that a fully loaded JPX6 carries 40ml of irritant.
The irritant can cause temporary blindness, coughing and nausea that last at least 45 minutes before these effects start to fade, according to Piexon.
Paul Au, a doctor with Médecins Sans Frontières, told Apple Daily that exposure to such irritants for three to five minutes alone may trigger asthma attacks or be lethal for someone with underlying respiratory illness. Temporary blindness for such a period could also put them in life-threatening situations if they get caught up in chaotic protests, he added.
The new pepper spray tool is capable of firing irritants at a speed of 80 meters per second and unlikely to be blown off course by heavy wind. It has a minimum safety distance of 1.5 meters, and a maximum effective range of seven meters.
Local media earlier reported that the police's elite Special Tactical Squad, known as raptors, could be given the new pepper spray pistols by the end of this month.
Demosistō, a pro-democracy political group co-founded by activist Joshua Wong, has started an online petition to demand the Swiss government to ban the sale of such weapons to Hong Kong. The petition has collected almost 58,000 signatures as of Saturday evening.
The Hong Kong Police Force has yet to respond to Apple Daily's request for comment.