Philippine authorities said Thursday the poison in a batch of candy that sent nearly 2,000 children to hospital was likely a common germ from dirty hands or sweaty armpits.
Health Secretary Janette Garin appealed for better hygiene standards in the food industry, as she announced test results indicating a bacteria found in human skin and hair likely contaminated the sweets.
"This could be because they (candy makers) did not wash their hands, or their sweat dripped into the candy, or the candy touched their armpits, or they didn't wash up after going to the bathroom," Garin told reporters.
At least 1,925 people, mostly children, in the southern Philippines were hospitalised over the past week with stomach cramps, vomiting, diarrhoea and other illnesses after eating the fruit-flavoured candy.
Nearly all have since recovered, with only one remaining in hospital.
Poor enforcement of food safety regulations has been blamed for past cases of food poisoning in the Philippines, an impoverished nation of 100 million people.
Garin acknowledged that the government has had a tough time enforcing food safety rules in small towns, where businesses prepare candy, rice cakes and other sweets in their home kitchens.
"These backyard industries are not regulated by the FDA (Food and Drug Administration)," she said.
"The bottom line is, hygiene is often overlooked." The bacteria identified by Garin as the likely culprit can be easily neutralised with heat or common sanitising agents, according to the US Food and Drug Administration's website.
However Garin said the laboratory tests on the sweets had not been fully completed, and further testing was underway to check for the presence of pesticides and toxic chemicals.