A nanny blacklist created by an alliance of 30 housekeeping service agencies in Shanghai to better regulate the market and drive out unsuitable caretakers has added the first names to its no-hire list.

Agencies in the alliance will refuse to consider nannies placed on the list, which is believed to be the first of its kind in the city.

One of the blacklisted nannies presented a fake health certificate while two others repeatedly failed to show up for interviews or scheduled jobs, said Xia Jun, president of the Shanghai Changning District Homemaking Service Association and an alliance founder.

"The 30 agencies in the alliance have roughly 1,000 chains in Shanghai and nearly 10,000 all over the country, including some doing service for foreign families. Any nanny that is found by any of the agencies to encroach on the seven taboos will be blacklisted, and their information will be shared by the persons in charge of the 30 agencies in a chat group on WeChat," Xia said.

Prohibited behavior includes fabricating identification or resumes, refusing to pay a brokerage fee to the agency, borrowing money from the employer, asking for higher pay in the middle of a contract or leaving the job if a pay hike is not granted.

"We have encountered such cases frequently. Some exaggerated their work years and experience and others borrowed money from the employer, but didn't repay. That's why we want to deter such people, and those with bad credit records, from the industry and protect the interest of our clients with our utmost efforts," Xia said.

Nannies are great demand in big cities. More than 20 percent of Shanghai families are using or plan to use nannies for at least several hours every day, according to a poll conducted by the Family Development Research Center of Fudan University. Results of the poll, which surveyed nearly 2,300 households, were published in December.

"As aging quickly gathers pace and more couples plan for another child, the nanny market will expand more rapidly," said Hu Zhan, an associate professor at the university's School of Social Development and Public Policy.

In one high-profile case, a nanny was accused of killing an older women she was hired to look after in Guangzhou, the capital of Guangdong province.

The 45-year-old nanny, surnamed He, told a court in December that she was lured by the employer's promise of a full-month's pay should the women die in the middle of a month. On her fourth day on the job, she put poison in the woman's soup and then strangled her, prosecutors said. A verdict is pending.