Chinese officials have begun inspecting every shipment of N95 respirators, ventilators and other medical supplies for quality issues before export, a policy likely to delay the arrival of critical gear at hospitals around the world that are struggling to cope with the coronavirus pandemic.

The policy, announced by the General Administration of Customs on Friday, produced immediate delays on Saturday as manufacturers, freight agents and traders tried to understand how to comply. Depending on the city, they said, the delays could range from a few hours to a few days or longer as government officials rush to comply.

The new customs policy comes after a series of complaints from Europe that medical supplies from China had quality problems.

The new delays come as countries have complained that a global free-for-all for personal protection equipment has left acute shortages for doctors and nurses. These countries include the US, Spain and, most recently, Russia.

China is the world’s dominant producer of a wide range of medical supplies. Its manufacturing lead has widened in many sectors as it has engaged in a nationwide mobilisation of medical supplies production since late January, when Beijing ordered a lockdown in Wuhan to curb the rapid spread of the coronavirus there.

China’s daily production of masks and respirators soared from 10 million at the start of February to 116 million just four weeks later.

The Chinese customs agency said on Friday that it would assess the quality of medical supplies before export, adding to the checks that exporters already face. The agency had been checking whether medical supplies were accurately counted, whether the goods infringed on foreign patents and whether the documents accompanying shipments were fraudulent.

The agency gave no indication how long the quality testing might take.

Many factories already have their own quality inspectors. The government’s new rules require an additional check by customs inspectors or other government inspectors acting on their behalf.

The new rules cover China’s exports in 11 categories: medical respirators and surgical masks, medical protective clothing, infrared thermometers, ventilators, surgical caps, medical goggles, medical gloves, medical shoe covers, patient monitors, medical disinfection towels and medical disinfectants.