U.S. Law: Kosher & Halal Food Labeling

"Congress shall make no law respecting an establishment of religion."

Nationwide (U.S.), there can be no legal definition of nor regulation of 'kosher' or 'halal.' The First Ammendment of U.S. Constitution lays out the Constitutional Principal of Separation of Church and State, prohibiting the government from making laws "respecting an establishment of religion" or the free exercise thereof. 

"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."[1]

Therefore, there are no legal mechanisms to regulate the standards used by food manufacturers. Legally, manufacturers can use either word on product labeling, or call their products 'kosher' or 'halal', simply if they believe that the food meets these standards. This practice of labeling a food or ingredient like gelatin as 'kosher' is effective in attracting a significant portion of the "kosher consumer" most of whom are Muslims.

U.S. Law Protecting Trademarks
U.S. Intellectual Property Law provides protection against the unauthorized use or misuse of trademarks—distinctive signs used by the owner to distinguish products and services that it provides from those provided by others. 

Halal and Kosher certification agencies use their recognizable and legally protected symbols on products they certify as either halal or kosher so that the consumer will be assured that the product in question meets the certifier's standards for halal or kosher.

Letters, such as 'K', 'KD' or 'KP' are not uniquely identifyable and cannot be protected under U.S. trademark protection laws. Manufacturers sometimes use the letter 'K' to identify its product as conforming with Jewish dietary law. Such products should not be understood to be kosher or halal for Muslims to eat.

Halal and Kosher symbols are registered trademarks of the certification organization, and cannot be placed on a food label without that organization's permission.

[ Halal Food Certification Agencies ]

[ Kosher Food Certification Agencies ] 

Local & State Law
Some cities, such as Baltimore, and some 20 states, including Virginia and New Jersey, recently passed legal statutes to define "kosher" and "halal" and to made it a crime to sell a product labeled as such if, in general, it was not processed in accordance with the Jewish and/or Islamic religious law. However, these statutes were ruled unconstitutional by courts (Baltimore, NJ) and legislatures (Virginia) and struck down.

Although the ordinance's "commendable" purpose is to protect consumers from fraud and mislabeling, U.S. District Judge Benson E. Legg, who struck down Baltimore's kosher statute, said, its "primary defect is that it excessively entangles civil and religious authority."[2]

As a measure to ensure that the public was kept knowledgeable in a constitutionally acceptable way, the State of Virginia recently passed laws requiring kosher and halal certification agencies to disclose the name of the person overseeing the food production process after it was discovered that some butchers were buying supermarket meat and repackaging it as kosher. 

The Virginia law reads:
"It is unlawful to label any repackaged food that represents the food as kosher or halal without indicating the person authorizing such designation."

The previous Virginia statute had required all kosher symbols to attest that the food had "been prepared under the Orthodox Hebrew religious requirements," but it was defeated in the Virginia State Legislature as unconstitutional.[3]

Related Topics:
Halal Certified Food Symbols 
Kosher Certified Food Symbols
Kosher v. Halal: What are the differences and similarities of kosher and halal?
Market for Halal Products & the Muslim Consumer

References:
[1] First Ammendment to the United States Constitution.
[2] Valentine, Paul W. "Kosher Law Ruled Unconstitutional; Baltimore Decision Against Food Inspections Is First at Federal Level." The Washington Post. October 5, 1993
[3] Shinefield, M. Chabad Lubavich Global Network. "Jewish and Muslim Communities Cooperate to Pass US's First Kosher-Halal Law." October, 2006. 
http://lubavitch.com/news/article/2016002/Jewish-and-Muslim-Communities-Cooperate-to-Pass-USs-First-Kosher-Halal-Law.html
(Retrieved April 8, 2009)