Coffee and Caffeine FAQ

The answer to that is it depends on the country. A few examples of laws related to caffeine content for food and drinks include the following:

In the United States there is a limit of 65mg of caffeine per 12 liquid ounce in beverages. This may only be for carbonated beverages. (What we call coke here in the south and my northern friends like to call pop.) There is also a limit of 200mg in pills such as Vivrin. For more info on caffeine contents in drinks check out  High Caffeine Pop from 'Energy Drinks' Revealed. Also check Ask Erowid for more specifics.

Here is the FDA regulation text:

[Code of Federal Regulations]
[Title 21, Volume 3]
[Revised as of April 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR182.1180]

[Page 462]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 182--SUBSTANCES GENERALLY RECOGNIZED AS SAFE--Table of Contents
 
            Subpart B--Multiple Purpose GRAS Food Substances
 
Sec. 182.1180  Caffeine.

    (a) Product. Caffeine.
    (b) Tolerance. 0.02 percent.
    (c) Limitations, restrictions, or explanation. This substance is 
generally recognized as safe when used in cola-type beverages in 
accordance with good manufacturing practice.

This text is available at the GPO web site. Essentially what this means is that for a drink or food to fall within the FDA's guidelines 68 mgs per 12 oz is acceptable. Some drinks do have more. Most if not all energy drinks are legally classified as supplements. Supplements (vitamins and such) have a much lower oversight than food and drugs. Natural caffeine levels are also exempt from these regulations so coffee based drinks may have more caffeine than the limit without being classified as a supplement.

Australia has a limit of Australia 145mg of caffeine per liter for non-energy drinks which they refer to as "formulated caffeinated beverage" for legal purposes. Formulated caffeinated beverages can contain up to 320 mg/L of caffeine but not less than 145 mg/L of caffeine.

In parts of Northern Thailand it is completely illegal. It was outlawed as a precursor to meth.