BANGKOK — A self-proclaimed volunteer on Friday refused to comply with orders from officials to stop soaking members of the public with mysterious chemicals that supposedly combat the coronavirus.

Somsak Sripetch, who was seen spraying commuters at Victory Monument earlier this week, told Channel 3 he would apply the chemicals to those who requested it, though he would refrain from using it on random strangers in the public.

Channel 3 also showed a footage of him dousing security guards inside a building with his spray, despite officials at the Food and Drug Administration saying the chemical is likely dangerous to human bodies and should not be used in public without permission.

“According to the law, anyone who is in possession of the substance must declare it to the Food and Drug Administration,” a legal officer at Thailand’s FDA said in an interview Friday. “If they want to disperse in a public space, they will need to seek approval from the FDA before doing so as well.”

The chemical in question was identified as Bescon P-A, which is classified by the FDA as “hazardous substances” according to agency deputy sec-gen Supatra Boonserm.

“It is allowed to be used as a surface disinfectant, but not to be used on humans since it can cause irritation,” Supatra said Thursday.

In a video taken by a bystander and posted on Wednesday, Somsak is seen dousing a line of commuters from head to toe at the transportation hub of Victory Monument. The video soon drew questions over its safety from netizens.

Somsak stepped forward on Thursday and maintained the chemical was safe, though he would not disclose the what types of substances were used.

Somsak identified himself as a volunteer who wants to help Thailand through the crisis. Online searches show him to be a businessman from Nakhon Pathom who’s participated in charity programs.

“I confirm that the disinfectant I used is well-sourced. I used it to spray myself. If it is deadly, I would die first,” Somsak told Khaosod. “The whole country can blame me for this, but I don’t want Thai people to get infected by the virus.”

But the FDA was less than pleased.

FDA official Surachoke Tangwiwat warned members of the public against skin exposure to sanitizing chemicals, which may not even be effective against the coronavirus.

“We found that typically-used chemicals like benzalkonium chloride cause minor irritation to people, Surachoke said. “But if they are just irritating, it means that its effectiveness in killing germs is weak as well. Many of them can’t be used to kill the virus.”

Surachoke recommended the public to frequently wash their hands after touching or sneezing, and wiping surfaces thoroughly with alcohol or sodium hypochlorite.

Ratchathewi district chief Rujira Arin also said on Thursday she has ordered the Somsak to stop his spraying campaign, since it was not approved by officials.