High school students who unknowingly drank smoothies containing potentially contaminated whey protein have been reassured they are not at risk of developing botulism.
Fonterra revealed on 3 August that 38 tonnes of its whey protein used by other manufacturers, including infant formula, was contaminated with a bacteria that can cause botulism. The whey protein was tainted by a dirty pipe at its processing plant in Waikato in May 2012.
Palmerston North Girls' High School says Fonterra told it on Friday morning that a 12kg bag of whey concentrate, which was part of a batch recalled, was provided to the school in February this year.
Fonterra says it established this on Thursday night and representatives visited the school on Friday.
About 25 students used the concentrate in a science project in April to make smoothies, which they then drank.
Principal Melba Scott said she has met with students to reassure them they are not at risk. She said there have been no reports of ill-health and the product was last consumed on 19 April, so the incubation period for illness has passed.
Ms Scott told Radio New Zealand's Checkpoint programme on Friday she understands the way the drinks were made meant there was very minimal risk to anyone who consumed them.
She said representatives from Fonterra were at the school all day and "really sorry our school had been caught up in all of this. But of course, whenever a product is recalled, anybody could be caught up in it. We really appreciated the partnership we had and we appreciated the way in which they came to assist the school."
Fonterra's chief technology officer Jeremy Hill told Checkpoint the whey protein contains spores that could lead to the botulism bacterium developing, but the risk to the students was very small. He said the risk to adults and adolescents is smaller than the risk to infants, which is itself quite low.
Dr Hill said the 12kg bag was donated to the school by Fonterra's Innovation Centre, and this should not have happened. All the remaining product at the school has been returned to the company.