Some 9,000 runners took part in the Colour Run yesterday, which went smoothly despite a series of hiccups in the lead-up.
The runners, who wore white, were doused in coloured cornstarch at each kilometre mark of the 5km non-competitive run in Sentosa. Another 7,000 are due to run in the event's second day in Sentosa today.
Mr Greg Hooton, vice-president of organiser IMG Events in Asia-Pacific, said: "There's never been an incident (at our events) so I had no concerns, but we (worked) with the authorities to make sure they had no concerns too.
"It's important that everyone who comes along today enjoys himself, understands he is safe, and just has a great time."
The event made headlines as concerns about the use of coloured powder were raised after a dust explosion at a "colour party" in Taiwan in June left at least 10 partygoers dead and more than 500 injured.
Police and the Singapore Civil Defence Force approved permits for the Colour Run only about a week ago after assessing the powder's safety. By then, some had already pulled out of the event. The organiser declined to provide figures.
Main sponsor CIMB Bank also withdrew last Thursday as several of its promotional activities were suspended amid safety tests.
Participant Muhammad Shaindra Majilan, 16, a student, said: "I took part last year as well and there was no problem at all. This is a fun event and a very different kind of run. I hope to take part again next year."