Apple Inc.'s rivals aren't rushing to emulate the iPhone maker's decision to subject supplier factories to audits by a labor group. Instead, they're sticking to internal checks that may leave room for violations — and negative public relations fallout.

Apple said on Feb. 14 the Fair Labor Association had started independent audits amid criticism of conditions at its plants in China. Companies including Microsoft Corp., Dell Inc., Hewlett-Packard Co. and Samsung Electronics Co. rely on their own evaluations, based in part on guidelines from the Electronic Industry Citizenship Coalition, which they say are sufficient to prevent abuses.

Though Apple's decision to join FLA may not root out all instances of labor abuse, the EICC's member companies may open themselves to even harsher criticism. While the EICC sets standards for ethics, worker safety and labor practices, it doesn't require members to disclose findings and it lacks enforcement powers. The result is a disjointed system of self-imposed regulations that fail to hold companies accountable when abuses arise, according to labor advocates and technology executives.