The country is battling its worst Covid outbreak since the beginning of the disease, and foreign businesses are having a hard time getting workers back to work.
Less than half of employees in the U.S. and UK are able to return to work after Covid restrictions began.
Since March, mainland China has imposed travel restrictions and stay- home orders in economic hubs from the southern city of Shenzhen to the northern province of Jilin. The amount of Covid controls varies by region.
The lock downs in the southeastern metropolis of Shanghai have been among the most disruptive to daily life and to foreign businesses and their supply chains. The city is home to the world's busiest port and accounts for 3.8% of China's GDP.
The Ministry of Industry and Information Technology sent a team to Shanghai. 666 major businesses in industries such as chips, biopharma and auto and equipment manufacturing were called for to be prioritized by the ministry.
Many companies still face the challenges of labor shortages and logistical difficulties.
The European Union Chamber of Commerce in China has a significant number of members on the whitelist, particularly in sectors of manufacturing, chemicals and autos.
She told CNBC in a statement that many companies still face labor shortages and logistical difficulties.
Being on the list means a factory could resume operations if workers live at the production site and contact is limited to people with valid negative virus tests.
Matthew Margulies, senior vice president of China operations, said that the requirements to achieve closed-loop status may not be possible with the re-opening of the whitelist.
Foreign business organizations said that companies can't easily bring in new staff for other shifts because of the difficulty of getting workers into factories.
Some companies that were subject to Covid lockdowns were able to maintain minimal operations under closed-loop protocols before the list was released.
When companies try to bring in new workers, they usually fail with the local communities who don't want to let people out.
The only good thing about the current situation is it’s so obviously unsustainable for the economy and all the companies that it will not last too long.
Covid-related restrictions on travel are a challenge for workers who do get permission to leave their apartments.
Delivery of parts can be affected by transport restrictions.
There is a fear among truck drivers that if they have to go to that factory for 14 days, they may skip that delivery and do something else.
It is a really good outcome for a business to be able to operate at 30% capacity in a week or so.
The current situation is unsustainable for the economy and all the companies will not last long, he said.
There are local restrictions that vary from province to province.
The differing measures have taken a toll on businesses.
A measure of China's road freight transport turnover fell by 27.2% nationwide from April 1 to 17 from a year ago, according to a report.
The report said that the transport measure plunged in Shanghai.
China's central government has called on local authorities to support transportation services and remove constraints, such as making drivers wait for virus test results before moving on.
Richard Yu, the CEO of the consumer business group of the Chinese company, warned in a post last week that if work and production in the city can't resume by May, all the companies with supply chain ties to the region will need to stop.
The contents of Yu's post were first reported by Chinese media. The post came around the time the government announced the whitelist.
The ministry of industry told reporters that the problems were temporary and that the authorities would improve the system.
On the other hand, we think the government is aware of how important the city is. The American Chamber of Commerce in China says that 600 manufacturing companies is a good first step, but there are thousands of manufacturing companies that are shut down in China.
Some of our companies in northern China contacted us, but their key suppliers in Shanghai are not allowed to restart.
Foreign businesses in China have different states of returning to work. There are 20,000 new daily Covid cases in Shanghai.
The factory in China was back up and running as of Wednesday, according to the CEO.
While most of its China manufacturing sites were operating normally or under closed-loop management, those in Shanghai remained shut, according to the American chemicals company.
When our colleagues are allowed to leave from community health management, our manufacturing sites in Shanghai will resume production.
Volkswagen said it was evaluating how feasible it was to resume production at its plant in Anting on the outskirts of Shanghai, while its factories in the northern city of Changchun in Jilin province have gradually resumed production.
Some of the company's sites in China have been under local management restrictions since late March.
The company said that there have been individual raw material supply issues, logistical disruptions and labor shortages that are impacting their operation and business.