The police say a new weapon they are introducing in the wake of the social unrest of 2019 will help officers fire pepper spray at suspects more accurately.
The pistol-like launcher can fire four rounds of pepper solution from up to seven metres away, the force said.
Hong Kong Island's emergency unit will be equipped with the device from Sunday as part of a three-month-trial that will determine whether all frontline officers should be given them.
Superintendent Yuen Wing-hong said the pepper solution will not cause permanent damage to the target and all effects, such as coughing, irritation to the eyes, nausea and skin swelling, should subside within 45 minutes.
The Switzerland-based manufacturer of the launcher says a safe distance to fire the weapon is at least 1.5 metres from the target.
Yuen said the force's internal guidelines are even more stringent than those of the manufacturer.
"The manufacturer's guidelines say it's okay to aim at the head, whereas we tell officers to aim at the centre mass of the body," he said.
"Will there be a problem if it's fired at close range? I think if you shoot people in the eye at a distance of zero metres of course there will be consequences."
Yuen said the launcher could be used against people without weapons, depending on the threat.
Police said the barrel of the launcher is orange in colour and the weapon will be placed on officers' chests – so they don't mix them up with their normal gun.