Synlait has successfully renewed the registration of its Dunsandel plant, allowing it to continue exporting canned infant formula to China.
The registration was issued by the General Administration of Customers of the Peoples' Republic of China (GACC).
Synlait chief executive Leon Clement said GACC had strict criteria that overseas manufacturers must meet to maintain registration.
Re-registration was required every four years and included a comprehensive assessment for which Synlait was asked to prove it had robust systems for change management, pathogen management and food incident management.
A three-day audit conducted by the Ministry for Primary Industries, on behalf of GACC, also included a full traceability exercise from raw materials through to export, as well as an assessment of Synlait's capability to meet China's rigorous regulatory requirements.
Synlait first obtained certification for canned infant formula for its Dunsandel site in September 2014.
Last month, Synlait announced work was on track with the building of a $260 million second nutritional powder manufacturing factory, at Pokeno.
The first Waikato dairy farmers to supply the factory had been signed up and the first nutritional spray dryer was expected to be ready for the 2019-20 season.
Once commissioned, the dryer would be capable of producing up to 45,000 metric tonnes of nutritional powders each year. That included infant-grade skim milk, whole milk and infant formula base powders.
The increased capacity was needed to match growing demand for infant formula product from Synlait customers, including a2 Milk Company, New Hope Nutritional, Bright Dairy and Munchkin.