Hewlett-Packard, one of the world's largest makers of computers and other electronics, is imposing new limits on the employment of students and temporary agency workers at factories across China.
The move, following recent efforts by Apple to increase scrutiny of student workers, reflects a significant shift in how electronics companies view problematic labor practices in China.
Many factories in China have long relied on high school students, vocational school students and temporary workers to cope with periodic surges in orders as factory labor becomes increasingly scarce. Students complain of being ordered by school administrators to put in very long hours on short notice at jobs with no relevance to their studies; local governments sometimes order schools to provide labor, and the factories pay school administrators a bonus.
For much of the last decade, many of the world's big electronics companies have largely neglected the problem, beyond in some cases tracking reports of the abuses. Apple made the unusual move last year of joining the Fair Labor Association, one of the largest workplace monitoring groups, which inspects factories in China that make computers, iPhones and other devices under contract from Apple. And last month, Apple said it would begin requiring suppliers to provide information about their student workers "so we can monitor this issue more carefully."
Now H.P. is pushing even harder. Its rules, given to suppliers in China on Friday morning, say that all work must be voluntary, and that students and temporary workers must be free "to leave work at any time upon reasonable notice without negative repercussions, and they must have access to reliable and reprisal-free grievance mechanisms," according to the company.
The rules also require that student work "must complement the primary area of study" — a restriction that could rule out huge numbers of students whose studies have nothing to do with electronics or manufacturing.
Enforcing workplace rules in China has always been difficult, as even Chinese laws on labor practices are flagrantly ignored by some manufacturers as they struggle to keep up with production demand amid labor shortages. The Chinese government announced last month that the nation's labor force had begun to shrink slowly because of the increasingly rigorous one-child policy through the 1980s and 1990s.
But complying with the new rules might be easier for suppliers contracting with H.P., which has relatively steady demand through the year for its products, than for suppliers working for rivals like Apple, with its big bursts of sales when new models are introduced.
Howard Clabo, an H.P. spokesman, said that the company would hold training sessions for suppliers starting in March and also discussion sessions for government officials, nongovernment organizations and academics — an initiative that could put pressure on other companies.
Tony Prophet, H.P.'s senior vice president for worldwide supply chain operations, said in a phone interview that H.P. was also capping the combined number of students and temp workers at any supplier factory at no more than 20 percent of labor during peak periods, which tend to be during summer vacations and the lengthy Chinese New Year holiday. H.P. plans to reduce that to 10 percent, but has not decided when, Mr. Prophet said.
The practice of employing students and temporary workers has been at the center of growing criticism of employment practices at Chinese suppliers used by big international electronics companies. Some of the companies are now seeing that the problems can harm their reputations.
In announcing increased scrutiny of student workers last month, Apple said in its supplier responsibility report that the "cyclical nature" of the student work "makes it difficult to catch problems."
"We've begun to partner with industry consultants to help our suppliers improve their policies, procedures and management of internship programs to go beyond what the law requires," Apple said.
Mr. Prophet of H.P. presented his company's new rules as a sign of corporate responsibility, as opposed to a competitive maneuver. "We're doing this because we think this is an important issue, and there are certainly concerns around it and some ambiguity around the appropriate standards," he said.
Labor activists have been particularly critical of Foxconn, a large Taiwanese contract manufacturer that produces electronic devices for Hewlett-Packard, Apple and other companies.