WASHINGTON — Fears were raised Thursday that five million inserts added to bullet-proof vests given to US troops, currently fighting in two wars, may not meet standards due to poor testing, a Pentagon report said.

The inserts made of synthetic fibers known as Kevlar or ceramic are meant to halt small caliber projectiles or other shrapnel.

They were manufactured between 2004 and 2006 by seven firms in a contract worth some $2.5 billion, according to the Pentagon's inspector general.

"The Army lacks assurance that 5.1 million ballistic inserts acquired through the seven contracts provide appropriate protection," the report said.

"We determined that ballistic testing and quality assurance for Interceptor Body Armor inserts did not have proper controls to ensure that the ballistic inserts met contract requirements.

"Consequently, the Army cannot be sure that the appropriate level of protection has been achieved."

According to quality control the inserts should be tested at an ambient temperature of around 58 to 78 degrees Fahrenheit, or 14 to 26 degrees Celsius, with humidity levels of around 40 to 60 percent.

However, the report found that in 52 percent of the cases these conditions were not met.

A Pentagon report published by the New York Times in January 2006 found that 80 percent of the Marines killed in the Iraq war from chest wounds would have survived if their bullet-proof vests had been more effective and had covered them more.