"Adult sex toys contain the same toxic substances that EU banned from use in children's toys," said Greenpeace.
The environmental group said it was shocked to find that seven of the eight sex toys it had tested contained between 24% and 51% of phthalates.
"It is unbelievable that such toxic substances can be used in adult toys.
Greenpeace spokesperson Bart van Opzeeland said: "We have tested many products in the last few years but never have we encountered such high concentrations."
Greenpeace research has shown that phthalates can disrupt the human hormonal system, diminishes fertility and adversely affects the kidneys and liver.
The substance is used to soften plastics and PVC plastic.
Greenpeace stressed that a ban on phthalates would not mean the disappearance of people's favourite sex toys as there are plenty of non-toxic alternatives.