Paraxylene, an inflammable petrochemical used to make plastic and polyester, became the focus of public attention last week after a rumour that a factory will be built to manufacture the substance in suburban Shanghai drew thousands to the streets.

The word paraxylene, more widely known in China as “PX”, has triggered nearly a dozen protests across the country in the past eight years. Despite the authorities’ repeated efforts to reassure the public over the chemical’s safety, PX continues to touch a nerve among a swelling middle-class that is increasingly outspoken and health-conscious.

“People in China generally don’t trust the government especially on issues that have to do with environmental assessment, people just think the government is lying,” said Maya Wang of the Human Rights Watch.

Anti-PX protest in Shanghai. Photo: 柚子爱上寂寞 via Weibo.

In 2007, hundreds of people in Xiamen, Fujian Province took a collective “stroll” on the streets in protest against a PX factory which was approved and under construction. The protest came after a message warning people about PX causing leukemia and birth abnormalities was widely circulated. The local government halted the construction of the facility but the public was not satisfied. Six months later, the project was relocated to the Gulei Peninsula in Zhangzhou city, more than 100 kilometres away from Xiamen. In 2013, an explosion caused by a hydrogen leak hit the Zhangzhou project. The facility had not been put into production so no one was injured.

Anti-PX protest in Xiamen in 2007. Photo: Zola

In 2008, a similar “strolling” demonstration took place in Chengdu, Sichuan Province. The protesters walked in silence along historical landmarks in the downtown area for two hours, wearing face masks. Another rally was planned on the fifth anniversary of the demonstration – however, it did not take place as activists and petitioners were held or closely monitored by the authorities.

In 2010, an oil spill on the outskirts of the coastal city caused explosions and an ecological disaster, raising public concerns over environmental safety.

In 2011, thousands of people in Dalian, Liaoning Province rallied outside government headquarters to demand a PX factory be moved out of the city. Wearing T-shirts with anti-PX slogans, the protesters sang the national anthem. A report by state news agency Xinhua said over 12,000 people took part in the rally.

Anti-PX protest in Dalian in 2011. Photo: 大连老马 via Weibo.

In 2012, violent demonstrations broke out in Ningbo, Zhajiang Province over the government’s plan to expand a petrochemical complex, which included a PX facility. Dozens of people were arrested. The Ningbo government later cancelled the plan and promised it would not build any PX factories in the future.

Anti-PX protest in Ningbo in 2012. Photo: 小猪_JY via Weibo.

In 2013, hundreds marched in the streets of Kunming, Yunnan Province against a planned petrochemical plant. The protest took place on May 4, a historic date associated with the 1919 student pro-democracy demonstration.

Anti-PX protest in Kunming in 2013. Photo: 爱上喵滴旺 via Weibo.

In 2014, protests again erupted in Maoming, Guangdong Province over the government’s decision to build a PX facility in the city. The demonstration also spilled to other cities including Guangzhou and Shenzhen.

Anti-PX protest in Maoming in 2014. Photo: 豪仔 via weibo

The latest anti-PX protest in metropolitan Shanghai lasted for seven days despite the government saying repeatedly that no PX facility would be built.

Authorities were “skillful” in their handling of the protest, avoiding violent crackdowns and instead focusing more on blocking sensitive information and preventing the protests from spreading to downtown areas, said Wang. “The authorities used a combination of techniques of both control and appeasement to reduce the impact of the protest,” she said.

While the government is acquiring more and more sophisticated methods to deal with “mass incidents”, its attempt to educate the public on environmental issues keeps failing. The toxicity of PX remains disputed in China. While many people believe the chemical causes cancer, state media People’s Daily once argued it’s no more toxic than caffeine.

According to the International Chemical Safety Cards, PX, if inhaled or absorbed through skin or eyes, could lead to headaches, nausea and pain. Long term exposure may cause harm to the central nervous system.

However, a report by the UK Royal Society of Chemistry in 2011 said PX manufacturing has rarely caused environmental harm worldwide due to safety measures in place.

Vivienne Zeng

Vivienne Zeng is a journalist from China with three years' experience covering Hong Kong and mainland affairs. She has an MA in journalism from the University of Hong Kong. Her work has been featured on outlets such as Al Jazeera+ and MSNBC.