Lesbians in China have created an online petition urging the country’s government to eliminate a 1998 law that prohibits LGBT people from donating blood, The Associated Press reports. The petition has drawn 540 signatures so far, with the goal of reaching 1,000.

According to a spokeswoman from the Beijing Red Cross Blood Center, lesbians and gay men in China are barred from donating blood once they mark off their sexual orientation on the application form.

“It’s a practical law because the gay community has much higher rates of sexually transmitted diseases. We must take our precautions wisely,” she said. “Even if they lie on the form and say they are straight, everyone’s blood will go through a final screening test for diseases.”

UNAIDS and the Chinese government estimate that about 700,000 people in the country are HIV positive, of which 85,000 have progressed to AIDS. There are an estimated 30 million gays and lesbians in China.