What is the tolerance threshold under the EU-Mexico?

The general tolerance is 10% of the ex-works value of the finished product.

EU-Mexico - HS 27

EU-Mexico Global Agreement (FTA part)

13 RegelnToleranz: 10%2000

2701-2706Mineral fuels, mineral oils and products of their distillation; bituminous substances, mineral waxes

Manufacture in which all the materials used are classified within a heading other than that of the product.