Filipino chemists warned the public on Friday, July 31, that they should not use gasoline as a disinfectant, after President Rodrigo Duterte insisted otherwise in a televised speech and said he was not joking.

“Gasoline must not be used as a disinfectant,” said the Integrated Chemists of the Philippines in a Facebook post, warning that this can be harmful to humans especially when inhaled.

The ICP issued the advisory a few hours after Duterte’s address aired on Friday morning. 

During his speech, the President said: “Totoo ‘yang sinabi ko [sa] alcohol. ‘Pag wala kang alcohol, ‘di naman puwede na lalo nang mahirap, pumunta ka lang diyan sa gasoline station tapos patulo na.”

(What I said about alcohol is true. If you don’t have alcohol, especially if you’re poor, go to a gasoline station and get [gas].)

Rappler had also fact-checked Duterte when he first claimed on July 21 that gasoline or diesel can be used to disinfect face masks. There is no scientific proof for Duterte’s claim, and in fact the US Centers for Disease Control and Prevention said gasoline exposure can be toxic.

Deflecting criticism over Duterte’s July 21 remarks, Presidential Spokesperson Harry Roque said on July 22 that Duterte was once again joking when he said gasoline or diesel can serve as a disinfectant.

Duterte on Friday, however said: “Hindi ako nagbibiro. Totohanan iyon.” (I’m not joking. That’s true).”

“Sabi nito, si Duterte, loko-loko. Gago, kung loko-loko ako, ikaw na sana ang nag-Presidente, ‘di ako (They said Duterte is a crazy. Idiot, if I was a fool, you should have been President, not me),” he said. 

Duterte is among the world’s populist leaders, including America’s Donald Trump and Brazil’s Jair Bolsonaro, who have made unscientific claims about the COVID-19 pandemic as they lead the world’s hardest hit countries.

Trump suggested on April 23 that disinfectants can be injected in COVID-19 patients to treat them, a claim dismissed by experts as reckless.

Bolsonaro has his own share of bombastic claims, falsely declaring on March 24 that COVID-19 was a “little flu” that has generated “overblown” reactions. He would later test positive for the coronavirus – not once but thrice – while his country now has the world’s second highest number of coronavirus deaths, next to the US. – with reports from Sofia Tomacruz/Rappler.com