Legal news :Many exports to Mexico have to include the certification mark of product safety.

Mexican authorities require that a certification mark NOM (Normas Mexicanas Oficiales) found on certain imports, including for example for electronic products. This mark, which certifies that the goods in question meet the specific security requirements, must appear on each product concerned or - in case of a legal alternative - on its packaging.
 With the strengthening of customs controls in Mexico imports that do not include the official mark NAME may experience delays at customs clearance and are liable to customs seizures and / or fines. The customs authorities also have the right to refuse entry of such goods within Mexico and to order their return to the shipper's expense.
 We therefore advise all shippers and other electronic products to Mexico to ensure that all goods are in accordance with the instructions and marking NAME before arranging shipment.
 The main types of product to include a certification mark NAME:

    Hairdressing equipment (dryers and hair irons for example)
    Heaters
    Computer keyboards and power adapters
    Spare parts for printers
    Digital video cameras
    Rechargeable batteries for cell phones and laptops
    Plastic bags and covers for cell phones
    Wristwatches plastic
    Plastic belts
    Costume jewelery
    Make-up
Additional information is available at the following sites (in Spanish only):Normas Mexicanas Oficiales: 
http://www.economia-noms.gob.mx/noms/inicio.doServicio de Administracion Tributaria (SAT):
http://www.aduanas.gob.mx/aduana_mexico/2011/home.asp 

(Source FEDEX)