The Swiss team lodged a protest after Maze finished second in a super-G in Bad Kleinkircheim, Austria, last weekend, saying the plastic level in Maze's garments exceeded International Ski Federation (FIS) rules, giving her an aerodynamic edge.
The FIS issued a statement on Saturday saying "the air permeability rules were fulfilled" during a test of the one-piece undergarment "and consequently there will be no modification to the results of the competition."
However, the FIS added that the garment could be unsafe because it prevents the body from breathing.
"The analysis showed that the material of the one-piece undergarment contains a form of membrane which could be considered as a form of plastic," the statement said. "It is recommended that the one-piece undergarment not be used by any athletes in competition."
The Italian team also uses the undergarment, which is made by the Italian company Energia Pura.
Coaches of all teams informally agreed on Wednesday not to use the clothing until further tests.
Maze wore a different garment when she finished fourth in Saturday's downhill — missing the podium by 0.06 seconds.
"We are sure it's not plastic, but they want to test it," Maze said after the race but before the verdict.