8 local tempered glass manufacturers were ordered to suspend production after failing quality tests, the city's quality watchdog said yesterday.
Their substandard products are now being recalled, added the Shanghai Quality and Technical Supervision Bureau.
This follows a spate of incidents in the city involving safety glass shattering.
The latest occurred on Monday morning when a 3-square-meter glass door between a Starbucks outlet and other businesses in the Raffles City building at People's Square shattered. No one was injured.
The bureau checked 67 batches of tempered glass for construction use in its latest inspection and found eight had "serious quality problems" which posed safety risks.
These included failing tests of fragmentation, surface stress and impact resistance.
The Shanghai Shibei Glass Co Ltd failed impact resistance tests. The company says on its website that its glass is used in high-profile locations such as Raffles City, Westgate Mall and Shanghai Railway Station.
The Shanghai Mingliang Tempered Glass Co Ltd failed the same test. It also failed fragmentation tests last year.
The eight producers will only be allowed to resume production after passing tests.
And sales of their substandard glass have been suspended, said Shen Weimin, deputy director of the bureau.
They will also face administrative penalties, Shen said.
Monday's incident at Raffles City, which saw Starbucks evacuated, is still being investigated.
Shen said the probable cause was poor quality glass in terms of fragmentation, surface stress or impact resistance.
Legal use of meat glue
Checks by the Shanghai Quality and Technical Supervision Bureau of all 35 deep-fried chicken producers in the city found one of these producers used transglutaminase - also known as meat glue - in a small number of products.
But as it marked the ingredients on labels, this is permitted, said a bureau official.
Last month, Taiwan media said transglutaminase was used to make big chicken fillets.
Milk meets fresh standards
No irregularities have been found in locally produced milk, the Shanghai Quality and Technical Supervision Bureau said.
This follows national scandals, such as "fresh milk" found to be made from milk powder, dairy companies failing to correctly label milk made from milk powder and the use of banned or excessive additives.
Insiders this month said that more than 60 percent of liquid milk sold in China is made from milk powder and a variety of flavors and additives.
Amusement park rides grounded
Two rides at the Happy Valley amusement park were suspended after failing Shanghai Quality and Technical Supervision Bureau inspections.
The bureau said it will conduct thorough checks at theme parks - including the Playa Maya Water Park, the Jinjiang Amusement Park, Dino Beach and Happy Valley - as rides are more heavily used in summer.
On July 21, roller coaster riders were left stranded in mid-air at Happy Valley when their ride suddenly stopped.
