The validity of university teachers working in industry and other enterprises has been questioned again following a recent accident that took the life of a 25-year-old man in his academic supervisor's factory.

Li Peng, a second-year graduate student at the East China University of Science and Technology's School of Chemical Engineering at, died on March 23 in an explosion at Shanghai Joule Wax Industry Co Ltd in a western suburb of Shanghai. Nearly 200 square meters of color steel plate collapsed in the blast, which resulted in two more casualties.

Li was admitted by East China University of Science and Technology in September 2014. Zhang Jianyu, 55, was his supervisor.

Public information shows that Zhang is a shareholder in the Shanghai Joule Wax Industry and invested 1 million yuan ($152,000) in the company. Before June 30, 2015, Zhang was also the company's juridical, a position later transferred to his older brother, Zhang Jianjun.

Zhang and his older brother are now in criminal detention on suspicion of causing a major accident.

The university did not disclose any information about the accident until March 27. It wrote on its official Weibo account that the university and related governmental bodies have started an investigation into the accident.

The university's public relations department said that its officials were unaware of Zhang's businesses. Whether Zhang bears any responsibility is subject to the results released by the investigative team.

Li's family is not satisfied with the university's investigation results. They required municipal judicial authority to present Li's autopsy result and make DNA identification. They also asked for compensation totaling over 8.53 million yuan.

His sister wrote on her Weibo account that they were not informed of the accident until nine hours after it occurred. They are neither kept informed of the investigation nor allowed to meet Zhang's attorney.

But what infuriated them the most was that Li did the pilot-plant test on his own. The factory was in poor condition and no safety measures could be seen. Although the university said that no blast should have happened if Li's research result was reliable, industry experts said that pilot-plant tests include high risks. That's because they are conducted on a larger scale and done in factories rather than in labs. Li, who did the test for the first time, should have had his supervisor accompanying him.

As early as 2007, the university has prohibited teachers from taking substantive part-time jobs in enterprises or setting up their own companies.

But the regulation did not work for Zhang. Besides Shanghai Joule Wax Industry, he invested in another company in Shanghai and participated in management of a factory in Zhejiang province.

Zhao Zhongxin, a professor on the Faculty of Education at Beijing Normal University, said that it is quite normal to find that a growing number of university teachers are taking positions in companies.

"Their titles are really bewildering. We don't know whether to define them as teachers or bosses. Students have made great efforts and chosen you as their supervisor. If the teacher does not whole-heartedly lead their students, but rather uses them as assistants, it will totally mislead the students," he said.

But other voices disagreed. Yin Xiaobing, associate professor at the School of Business and Tourism Management at Yunnan University, once said "It is a disaster if university teachers only focus on their school job". Yin himself is the independent director of three public companies.

The State Council announced guidelines in May last year, encouraging professionals working in universities and scientific research institutes to start their own businesses while they are still in an academic post or to temporarily leave their educational post for three years to do so.

The United States offers good examples of combining industry with research at universities. But the rules are clear. At Stanford University, for example, professors cannot take any position in a company but can only act as consultants. They can only work one day a week at a company and 39 days in total during the whole school year. The projects they study should not be the same as those underway in Silicon Valley.