The scare over contaminated products made by the New Zealand-based dairy giant Fonterra has aggravated public concerns about the safety of milk powder products and tarnished the image of foreign food brands in China.

Fonterra, the world's largest dairy producer, admitted on Saturday that some of its whey protein concentrate, which is used to make infant milk powder and other products, had been contaminated with bacteria that can cause the sometimes fatal illness botulism.

The confidence of Chinese consumers in foreign brands is likely to have been further shaken by reports of dubious behavior by US-based Abbott Laboratories.

Media reports have alleged that Abbott had asked Fonterra not to reveal that it was one of the companies that used Fonterra's whey product and that some of its products had been packaged on a Fonterra production line that had residue of the tainted raw material. Whether the Abbott products concerned contained the contaminated whey or not, any attempt at a cover-up would trample over consumers' right to know and harm the image of the company.

Consumers are now in a dilemma. They have to reconsider their choices among foreign and domestic brands.

Many Chinese consumers would only buy foreign brands of infant formula after an infamous scandal in 2008, when it was found that the illegal addition of potentially lethal melamine by a domestic producer had caused the death of six children.

The market share of foreign brands rose to more than 50 percent last year from about 30 percent in 2008, and in some high-end infant formula market sections, it is as high as 70 percent, according to media reports citing industrial association figures. Such predominance will hardly be shaken in the short term, as domestic producers are still struggling to rebuild their image after the melamine scandal.

However, the Fonterra scare should convince regulators to take the opportunity to strengthen consumer protection and ensure all products, no matter whether from a foreign or domestic producer, are safe.

The State Food and Drug Administration has proposed a regulation which would require producers to have their own controlled milk sources and research and development capabilities before being granted a license for milk powder production.

If carried out strictly, the new rule will help improve the quality of China-made milk powder and help restore trust in the domestic industry.