Chewing gum was behind the hospitalisation of 200 pupils from the Trevor Manuel primary school in Fisantekraal, said the City of Cape Town.
Spokesman Wilfred Solomons-Johannes said the energy chewing gum had passed its expiry date, and contained large amounts of sugar and caffeine, which raised the pupils' blood glucose levels too fast, making them hungry and resulting in vomiting.
They were treated and were admitted to the Durbanville Medi-Clinic, the Kraaifontein Day Hospital, the Tygerberg Hospital and the Karl Bremer Hospital.
A few pupils found the gum on a nearby farm and distributed it to other students.
"The city's health department investigated the matter and samples of the goods were taken for laboratory tests," Solomons-Johannes said.
(Sapa, May 2011)