In a bid to tone down the botulism scare caused by the discovery of bacteria in whey produced at its Waikato plant, Fonterra assured New Zealanders that the risk of acquiring botulism is only one in a million.

Fonterra supplied 38 tonnes of whey to eight major customers in New Zealand and several nations, but the largest New Zealand company and its customers had recalled 90 per cent of the tainted ingredient used for infant formula and sports drink. Fonterra Chief Executive Theo Spierings said that as of Wednesday, 10 per cent of the products were still unaccounted for.

"Everything is out of the market - it's in warehouse. There is little or no more risk for consumers," Mr Spierings said in Fonterra's Wednesday press conference.

He just flew back from China where he tried to do some damage control to Fonterra's reputation as manufacturer of premium products. However, despite his assurance to Chinese consumers, there was a lot of anxiety and confusion, although some appreciated the personal appearance of Mr Spierings and wrote about it in weibo, the micro-blogging site in China.

The very low chances of being hit by botulism appears to be true because a four-month-old boy from Invercargill was given infant formula from Nutricia's Karicare but the baby is free of botulism. The father said they were unaware that infant formula was from the same batch tainted by the whey from Fonterra.

The infant's father told Radio New Zealand he did not hear of the recall and continued to feed the baby the formula until he became sick on Monday. Tests, however, said the infant is negative for botulism but was diagnosed with a virus and prescribed panadol.

"We were quite disgruntled because we don't think there's enough done to be made aware. You could look online and stuff like that and find out about it if you've got that sort of technology, but I don't think there was enough done at all," the father was quoted by Radio New Zealand.

Despite the health risks caused by the botulism scare, the support service Plunket advised Kiwi parents to continue giving their babies infant formula instead of cow's milk because the latter has higher levels of protein and salt unsafe for babies' immature kidneys, said Plunket clinical advisor Allison Jamieson.

She advised them to use other brands except Karicare which has been identified to have the whey.