I dont have access to a phone at the moment that can call to the US.
Anyone know of a similar emergency line here in Mexico for Poison Control?
You can open a Skype account for free (hopefully in advance so you're prepared), and then call the US Poison Control Center at 1-800-222-1222 for free. (or any other US toll free number).
If you have trouble telling them the ingredients from what your kid just ate or drank because they are in Spanish on the label, don't use Google Translate or Babylon,
The absolute best translation website for chemicals & tech info translations that I have found for this is WordReference. Here is the Spanish to English section:
http://www.wordreference.com/English_Spanish_Dictionary.asp
When you find your kid sitting on the floor next to an almost-empty bottle of floor cleaner and blowing yellow bubbles, your Spanish skills might go right out the window and only your English works for the moment. Been there and done that. Good luck.