Some Indian states think so and have banned the sale of the pink, wispy, sugary-sweet treat.
Last week, the southern state of Tamil Nadu implemented the ban after lab tests confirmed the presence of a cancer-causing substance, Rhodamine-B, in samples sent for testing.
Earlier this month, the union territory of Puducherry banned the sweet treat while other states have begun testing samples of it.
Cotton candy, also called buddi-ka-baal (old woman's hair) in India because of its appearance, is popular with children the world over.
It's a fixture in amusement parks, fairs and other places of entertainment frequented by children, who like it because of its sticky, melt-in-the-mouth texture.
But some Indian officials say that the candy is more sinister than it seems.
P Satheesh Kumar, food safety officer in Chennai city in Tamil Nadu, told The Indian Express newspaper that the contaminants in cotton candy "could lead to cancer and affect all organs of the body".
His team raided candy sellers at a beach in the city last week. Mr Kumar said the sweet sold in the city was made by independent sellers and not registered factories.
A few days later, the government announced a ban on its sale after lab tests detected the presence of Rhodamine-B, a chemical compound, in the samples. The chemical imparts a fluorescent pink hue and is used to dye textiles, cosmetics and inks.
Studies have shown that the chemical can increase the risk of cancer and Europe and California have made its use as a food dye illegal.
While banning cotton candy in Tamil Nadu, Health Minister Ma Subramanian said in a statement that using Rhodamine-B in the "packaging, import, sale of food or serving food containing it at weddings and other public events would be punishable under the Food Safety and Standards Act, 2006".
Taking a cue from Tamil Nadu, the neighbouring state of Andhra Pradesh has also reportedly started testing samples of the candy to check for the presence of the carcinogen.
And earlier this week, the New India Express newspaper reported that food safety officials in Delhi too were pushing for a ban on cotton candy.
