The company that built 500 girders for the $1.7-billion Herb Gray Parkway says they're safe and should not have been rejected and removed.

In a media release, Freyssinet Canada says "comprehensive investigations" by "leading independent experts" have confirmed that the company's pre-stressed concrete girders "are entirely safe for use."

Freyssinet built more than 300 girders that were not to the Canadian Highway Bridge Design Code but were still installed. Hundreds more were built but not installed.

According to Parkway Infrastructure Constructors, the decision to remove the girders was not because the manufacturers used tack welding, which is against code. Rather, there was a discrepancy between documentation used for quality control and what was found during testing of the girders.

Freyssinet disagrees.

The company reached out to professor Maher Tadros, the inventor of the Nebraska University Girder, which is the type of girder the company says it constructed for the parkway project.

Freyssinet said the method has been used successfully throughout North America for more than 20 years.

Tadros checked the girders, reviewed Freyssinet's investigations and other published reports, and visited the fabrication yard on Russell Street in west Windsor.

Tadros concluded that the Freyssinet girders are suitable for the parkway project, the company said.

"I have not seen anything that would lead me to believe that the girders need to be removed or destroyed," Tadros said in a media release. "The three components of Freyssinet Canada's girders - concrete, prestressing steel and welded wire reinforcement - both meet and in some cases exceed project requirements."

However, in November, the province revealed that when inspectors tore apart girders, they found reinforcement steel that was not in shop drawings.

"The investigations support the conclusion that the decision to reject Freyssinet's girders was based on limited and inaccurate information," Freyssinet said in a media release.