Starting in 2015, Canadians who want to purchase and use citronella insect repellant will have to travel to the US, thanks to regulations imposed by Health Canada. Small manufacturers of the natural-based repellants couldn’t afford to submit the required safety data, though synthetic DEET easily passed the country’s health scrutiny process. “It’s the basis of the ban that I don’t really understand,” says toxicologist Sam Kacew. CBC News.