HONG KONG (Reuters) - More than a dozen Chinese labor rights groups are circulating a petition pushing for safer factory working conditions, in a bid to capitalize on public anger over the worst industrial accident in more than year.

A room filled with metal dust exploded on Saturday at the Kunshan Zhongrong Metal Products Co Ltd factory that polishes wheel hubs for carmakers, including General Motors Co, killing 75 people and injuring 185.

It was the worst industrial accident in China since June last year when a fire engulfed a poultry slaughterhouse and has once again thrust concerns about safety conditions in factories across the country to the fore.

"The reasons for the accident lie fundamentally with long-neglected labor rights," says the petition, which is circulating on Chinese social media.

"China is the ’world factory’ in the production of wealth - but also in the production of injury." ’Made in China,’ it says, "bears a heavy moral shadow."

Labor activism has surged in China over the past year as slowing economic growth and rising costs have squeezed companies in industrialized areas and mired some of the world’s biggest firms in hundreds of strikes and other work stoppages.

After Saturday’s blast, President Xi Jinping demanded a full inquiry and punishment for those responsible for the accident.

With anger building, Chinese authorities this week took the unusual step of suspending work at 268 factories for safety inspections in two centers of the eastern Jiangsu Province.

The petition, launched on Sunday by university professors, lawyers and non-profit organizations, outlines plans for workers to take part in factory safety checks and to use collective bargaining to set labor and occupational safety standards.

The petition also calls for better compensation and shorter working hours and has garnered more than 1,600 signatures in a few days. While a small number in a such vast country, citizens are often hesitant to put their names to campaigns which could be viewed as industrial unrest, for fear of retribution.

Activists hope momentum will build during the month the campaign is due to run.

"Despite improved wages, welfare and working conditions, there is still huge room for improvement in safety conditions in China," Wang Jiangsong, a Beijing-based professor and labor activist representing the campaign told Reuters by telephone.

In the past year, Cooper Tire & Rubber Co, Nokia Oyj, International Business Machines (IBM), ABB Ltd and Yue Yuen Industrial Holdings Ltd have all been involved in labor disputes in China.

Yue Yuen, which makes footwear for companies such as Nike Inc and Adidas, said this week it expected to book a $112 million provision to improve employee benefits, even though the charge will hit its results.

Workers’ safety is a broader problem in China, even outside factories. Many of China’s most deadly industrial accidents happen in the huge coal mining industry. In 2012, more than 1,300 people died from explosions, mine collapses and floods.

(Reporting by Clare Baldwin, Donny Kwok and Rachel Lee)