The ‘Ice Bucket Challenge,’ which has participants dump buckets of ice water on themselves in order to raise money and awareness for the ALS Association, has gone completely viral thanks to celebrity involvement – but not all the stars are into it. Pamela Anderson just made waves as the latest celebrity to reject the challenge, citing the association’s practice of animal testing. Could the PETA activist’s callout impact the success of this hugely popular campaign? Or maybe even change the way the ALS Association does its research?

Anderson addressed her beef with the organization via Facebook, in a post earlier this week. The former Baywatch star posted a photo of herself wearing a bikini and white T-shirt, holding up a sign saying “Stop Animal Testing,” along with an explanation of her position. In it she said of her decision not to participate, “I thought instead I’d challenge ALS to stop animal testing.” She went on to describe experimentation the association has allegedly performed, such as drilling holes into the mice’s skulls and injecting chemicals into monkeys’ brains and backs. The star says that these methods are not productive, as most of the treatments have not moved on to human trails.

Anderson has a long history of advocating for animal rights. The bombshell began working with PETA in 2003, when she did one of their famous ‘I’d Rather Go Naked than Wear Fur’ ads, in which she posed nude. In 2006 she began a campaign to end Canada’s annual seal hunt. In 2010, she received PETA’s Person of the Year award, in recognition of all the public speaking engagements and ad campaigns regarding animal cruelty she participated in that year.

It is unclear whether Anderson’s callout of the ALS Association will have any impact on the ‘Ice Bucket Challenge’ campaign, which has already helped the organization raise more than $41 million. While many celebrities, ranging from Anna Wintour to Justin Bieber have enthusiastically participated, Anderson is not alone in rejecting the premise. Actor Zachary Quinto explained on Instagram that he would not take part, due to “staggering drought in California and the desperate need for clean drinking water in developing countries.” He, however, supports the organization itself, and donated directly to them.