By Bernice Yeung, Reveal

That little green frog logo is everywhere: sprawled across chocolate bar wrappers, stuck to the side of tea canisters, perched on banana labels. The web-toed  amphibian is the Rainforest Alliance Certified seal, a signal to consumers that the product is friendly to the planet and to farmworkers.

But when it comes to worker protections, Rainforest Alliance hasn’t always delivered on its promises.

According to a report by the fair-trade watchdog organization Fair World Project, consumers should be skeptical of some certification groups, such as Rainforest Alliance. The popular green frog logo, in fact, was deemed “unqualified to ensure farmworker justice” because of weaknesses in its audits.

This follows on recent accusations that Rainforest Alliance is certifying products sourced from farms where workers have been mistreated.

In 2015, a BBC investigation found that workers on Rainforest Alliance-approved Indian tea estates lived in shoddy housing and received unacceptably low wages. Reporters also found evidence of children working on the plantations. The organization has acknowledged that its auditing process was imperfect, and responded by decertifying one tea estate, reducing the risks that lead to child labor and improving housing conditions.

But additional critical reports about the Rainforest Alliance certification process surfaced this year. Following a 2011 study that found a host of problems on Rainforest Alliance-certified Indian tea plantations, a worker advocacy group re-evaluated some estates this summer. The latest report found improvements, though it also noted ongoing issues related to overtime pay and unions.

The Rainforest Alliance and the Sustainable Agricultural Network, which jointly oversee the green frog label, sent in an audit team to look at these concerns but said it couldn’t corroborate most problems raised in the report, except for a minor issue related to working hours, which it has addressed.

And according to an Oxfam Germany report published last spring, there are problems with the labor conditions at Rainforest Alliance-affiliated banana and pineapple plantations in Latin America, too. Banana workers in Ecuador said that pesticides were sprayed by planes while they worked in the fields below, and pineapple workers in Costa Rica said that after working 12 hours a day, they still could not make ends meet. Rainforest Alliance has launched ongoing investigations into these claims but have not found evidence of these problems.

The recent inquiries focus in on farms that source products such as Lipton teas and Dole pineapples. Brands like Taco Bell, Clif Bar and Naked Juices also bear the little green frog logo.

Representatives of Rainforest Alliance and the Sustainable Agricultural Network said that when they learn of substantiated problems, they make changes.

“What we appreciate is constructive criticism and input, and we realize we do not have a perfect system,” said Andre de Freitas, the executive director of the Sustainable Agricultural Network, which creates the certification standards. “We are working on improving and engaging more with worker organizations. Our commitment is to getting better.”

The Rainforest Alliance certification program operates in 74 countries, and says it promotes sustainability in areas ranging from forestry to tourism. Food businesses can carry the frog logo by sourcing from certified farms, which pledge to follow specific environmental and labor standards. Though the Rainforest Alliance certification program is primarily funded by donations and philanthropy, some businesses pay a small royalty for the right to carry the logo.

The farms themselves pay to be certified. To make sure participating farms aren’t breaking the rules, the program conducts routine audits. The Justice in the Fields report, however, dinged Rainforest Alliance for inspections that were only once-a-year and pre-announced, and where worker representatives weren’t involved in the interview process – something the report says would make them more comfortable coming forward with complaints.

De Freitas said that the program is increasing the number of surprise audits and getting workers involved in oversight. He pointed out that the Justice in the Fields report contained verifiable inaccuracies and flagged issues around wages that the organization had already addressed through new standards announced in September.

Justice in the Fields evaluated seven of the largest certification programs that claim to ensure that products are free from farmworker exploitation. It looked specifically at labor conditions at medium- and large-scale farms, with an eye toward employee housing, wages and the enforcement of labor laws. (Some of these programs also monitor environmental practices, but the Justice in the Fields report only considered job conditions.)

Of seven certification programs, the report recommended four: The Fair Food Program, the Agricultural Justice Project, the Equitable Food Initiative and Fairtrade International.

The remaining three certifications make claims that “speaks to buzzwords around fairness, but their practices are not substantial enough to actually affect workers’ lives in a positive way,” said Kerstin Lindgren, the report’s author.

These weaker programs – Fair Trade USA, Fair for Life and Rainforest Alliance – should be approached with caution because of concerns over whether they pay a living wage or have strong auditing systems, Lindgren said.

But even the certification programs that received high marks from the Justice in the Fields report are not perfect. Florida’s Fair Food Programwas recommended by the Fair World Project, but the program is nevertheless silent when it comes to reducing workers’ exposure to pesticides.

Lindgren said part of the purpose of the report was to show the limits of certification programs. “For consumers, I hope they begin to become more aware and engage on these issues,” she said. In addition to getting involved at a policy level, she suggested that consumers “look for the strongest label and don’t assume that a weak label is better than no label.”