Here's a labor law truism: When the economy heads south, employment discrimination claims head north.

A record number of workers and job seekers filed workplace discrimination complaints in fiscal year 2010, the Equal Employment Opportunity Commission recently reported. The number of charges—which workers file with the commission when they think they have been unfairly treated based on race, sex or other protected categories—rose to nearly 100,000. That's up 7 percent from the year-earlier period and 21 percent from fiscal 2007, before the recession.    

Experts pegged the spike to a brutal job market, with workers arguing the recession has brought out the hidden biases of employers, who can now afford to be pickier when selecting a job candidate.

"When the pie shrinks, your selection criteria—why you picked this person over that person—comes under much greater scrutiny," says Merrily Archer, a former EEOC attorney under the Clinton administration, noting a similar rise in the aftermath of the 2001 recession.

The largest increase was among people who felt they had been discriminated against because of a disability, an uptick that may be linked to recent legislation that widened the legal definition of "disabled" and the EEOC's new education efforts on the topic—a hallmark of the Obama administration's deep interest in discrimination cases, Archer says.

"It could be that people are more aware of their rights now," says EEOC spokeswoman Justine Lisser, who rattled off a list of outreach tactics the commission has used under Obama.  

Employers, however, contend that many of the discrimination cases filed with the commission are baseless attempts by workers with no job opportunities. They point to the fact that the number of suits eventually filed by the EEOC declined last year, from 314 to 271.

Archer, who now represents employers for the national labor law firm Fisher & Phillips, says there's a caveat to the data: Equipped with the largest budget in its history and an additional 300 staffers, "the EEOC has taken the most aggressive stance I've seen throughout my whole career."

That could account for the spike in claims. So, small businesses should have their hiring practices audited and anticipate bias charges before they occur, rather than have their workplaces become hotbeds of discrimination, she adds.

Among the report's other findings: Racial discrimination, the most frequently filed charge since the EEOC was established in 1965, was outpaced for the first time last year by retaliation discrimination. A worker can file a retaliation complaint if he or she is fired or treated differently based on previous allegations of discrimination, according to the commission.