Can cornflour be deadly? That is what the tragedy during a party at a Taiwanese water park last Sunday seems to suggest.
Horrifying amateur video footage showed a ball of fire ripping through a crowd of young revellers who had been dancing in front of a stage and cheering as clouds of green and yellow powder covered them at the Formosa Fun Coast water park, just outside the capital Taipei.
About 500 people were injured, 200 of them seriously, as people were burnt not only on the skin but also because they inhaled the powder into their lungs.
Yet the water park's general manager Chen Hui-ying was quoted by AFP as saying: "Throwing coloured cornstarch around … we had never heard such an activity could be dangerous."
While investigations into the fire in Taiwan are ongoing, it's worth recalling an experiment by Stephen Fry on BBC Two (broadcast on Jan 24, 2014) which shows how even seemingly harmless custard powder can explode into flames once it's pumped with compressed air and passed through some sort of flame or spark.
Investigators were seeking a reason why the cornflour mix of coloured powder combusted after being sprayed over the partygoers from a machine mounted on a stage.
"The source of the heat is still under investigation," said Kevin Lo, an official with the city fire department told Reuters on Monday. "The powder itself is not considered dangerous goods."
Investigators are looking at three main possibilities: cigarette embers, a lighter, or electrical sparks, said Lo.
The New York Times reported that the powder used by Color Play Asia, the event organiser, was made of cornflour and food colouring, according to a post on the company's Facebook account. The post said its products were in line with standards set by SGS, which is a Geneva-based testing, inspection and verification company.
The event, billed as "Asia's biggest colour party", sees people dancing to music while spraying each other with coloured powder.
Spraying coloured powder at events has become trendy here in Malaysia too, for example The Color Run presented by CIMB Bank held in August last year in Kuala Lumpur.
Color Run, founded in March 2011, has events all over the world and are billed as the "Happiest 5k (run) on the Planet".
Gary Double, vice president of Corporate Communications for IMG Europe, who are the organisers of The Color Run, says: "The Color Run has no association with the venue, organisers, or equipment used at the Taiwan incident. However, we take the events that occurred in Taipei very seriously as the health and safety of our participants and our employees has always been at the forefront of our minds and actions.
"We have had zero fire-related incidents in five hundred global events with more than four million participants."
Last April, The Heart Foundation of Malaysia organised the Great Eastern Colour "My Heart Run" in Penang, which also saw participants being showered with colourful powder during a 5km run. The event manager for that event, Integer Asia, said the colourful powder used during that event was made from 100 per cent natural water-based cornflour. According to Integer Asia managing director Paul Harding, no flammables such as alcohol or petroleum were added in the production process of the powder.
"We purchased the powder from a supplier in India. The product was clinically tested and has a flash point of 181°C. It contains no hazardous combustion products," Harding said in a phone interview.
Thus far there have been no such incidents with entertainment concerts held in the country. Livescape Group chief executive officer Muhammad Iqbal Ameer, who has brought over acts including Backstreet Boys and organised the Future Music Festival Asia, said the company has not used any powder substance in any of their events for special effects. Iqbal added confetti cannon and CO2 cannon are typically used, employing the services of professional pyrotechnic companies only.
There is also the Hindu festival of Holi, where coloured powders are thrown with great gaiety over participants. But what is the powder made of? According to one supplier, it's made of non-toxic and "skin friendly" rice powder.
However, as shown in the BBC experiment, the crucial element is NOT the composition of the powder itself, but whether it's deployed under high pressure with a flame nearby.
According to the United States Department of Labor (Occupational Safety & Health Administration) however, any combustible material can burn rapidly when in a finely divided form. If such a dust is suspended in air "in the right concentration, under certain conditions", it can become "explosible".
The force from such an explosion can cause deaths, injuries, and destruction of entire buildings. For example, three workers were killed in a 2010 titanium dust explosion in West Virginia, and 14 workers were killed in a 2008 sugar dust explosion in Georgia.
The US Chemical Safety and Hazard Investigation Board (CSB) identified 281 combustible dust incidents between 1980 and 2005 that led to the deaths of 119 workers, injured 718, and extensively damaged numerous industrial facilities.
The list of dusts which can explode include agricultural products such as powdered milk, soya flour, cornflour, rice dust, spice powders, sugar, tapioca, cocoa powder, coconut shell dust, coffee dust, garlic powder, grass dust, malted hops, lemon peel dust, oat flour, peanut skins, tea and tobacco. Metal, plastic and charcoal dusts are also similarly liable to catch fire under certain conditions.
The Canadian Centre for Occupational Health and Safety official website adds that while some of these materials are not "normally" combustible, they can burn or explode if the particles are "the right size and in the right concentration". Therefore it recommends that any activity that creates dust should be investigated for the risk of it being combustible. Dust can collect on surfaces such as rafters, roofs, ducts, crevices, dust collectors, and other equipment.
"When the dust is disturbed and under certain circumstances, there is the potential for a serious explosion to occur," says the website.