The California Attorney General has opposed adding grilled chicken to the list of Prop 65 warnings because it conducted its own scientific review and found no evidence the levels of PHiP in a grilled-chicken sandwich rise to the level of a health threat.
Jones, the 2008 Grand Slam winner, joins fellow Welsh internationals full-back Lee Byrne, scrum-half Lee Byrne and tighthead prop Adam Jones on Gatland's injured list.
That list is part of the Safe Drinking Water and Toxic Enforcement Act of 1986, otherwise known as Prop 65, which prohibits businesses from knowingly exposing individuals to listed substances without providing a clear and reasonable warning.