Gwyneth Paltrow has slammed one of Jessica Alba's eco-friendly products.

The 'Iron Man 3' actress, 41, named and shamed a cleaning agent from her rival's ''non toxic'' line, The Honest Company, as being potentially hazardous, after reviewing it with experts for a post titled 'The Dirty on Getting Clean ' on her lifestyle blog on Friday (25.04.14).

She wrote: ''Many of the 'clean' products I proudly use (and have even touted on goop) have turned out to be a product of marketing, rather than actually safe.''

After seeking advice from the Environmental Working Group (EWG) and Gregg Renfrew of cosmetics company Beautycounter, the Oscar-winning star shared a ''What We Were Using'' list, featuring dozens of products she now considers to be unsafe, including The Honest Company's All-Purpose Cleaner, which claims to contain ''no harsh chemicals.'' said that Jessica's product: ''May contain ingredients with potential for acute aquatic toxicity; respiratory effects; nervous system effects,'' and gave it a ''C'' grade.

Gwyneth has decided to stop using the product, adding: ''I will never give up my perfume, but maybe I can switch to greener and unscented laundry detergent, and remove some of the hand soaps I thought were great until I checked them on . . . Food for thought.''

It seems there is no love lost between the blonde beauty and the 'Machete Kills' star, 32, as last year Jessica claimed she was ''much more grounded'' than Gwyneth.

While promoting her first book, 'The Honest Life: Living Naturally and True to You,' the 'Fantastic Four' actress and entrepreneur claimed her tips were more relatable than Gwyneth's advice on her website and in her cookbooks because she grew up less well off.

She said: ''Gwyneth Paltrow probably lives a very similar lifestyle, but I didn't grow up with a bunch of money, so my tips are much more grounded: repurposing things and making things at home.''

The duo have a number of mutual friends, including Gwen Stefani and Nicole Richie.