This website relies on information from the United States Alcohol and Tobacco Tax and Trade Bureau (TTB) and the United States Food and Drug Administration (FDA). 

These government agencies roles in food and drink safety can be confusing. So confusing that the FDA acknowledges it [link], "Often frustrating and confusing for consumers is determining the appropriate regulatory agency to contact. "

This page shares some information on what these agencies do and where you might start looking for information on any cocktail ingredients not (yet) listed on CocktailSafe. 

United States FDA

The FDA regulates food additives and dietary supplements, among other duties [link]. The FDA also approves color additives. It does not approve dietary supplements or food labels. 

Many of the items listed on CocktailSafe and used at the bar fall under the category of food additives.

• "Although FDA does not have premarket approval of food products, it has the authority to approve certain ingredients before they are used in foods. Those include food additives, such as substances added intentionally to food, and color additives." [link] 
• "Certain food ingredients, such as those that are considered “generally recognized as safe” (GRAS) by scientific experts, do not require premarket approval as a food additive. FDA has a voluntary notification process under which a manufacturer may submit a conclusion that the use of an ingredient is GRAS."

The FDA controls two important databases where you may find relevant information about cocktail ingredients:

• The Substances Added to Food inventory (formerly called Everything Added to Foods in the United States (EAFUS))
• The GRAS database -  Substances Generally Recognized as Safe. Note that often no results are found, but the search returns the message:"There were no records found that match your search criteria. Try searching related datasets." Be sure to click that link as it will often lead to results elsewhere. 

Often, searching the FDA's website will bring you to CFR 21, the Code of Federal Regulations Title 21. Much of the detailed information you may be after is found there. 

The FDA Food Code is not a law in itself but is is offered as a guideline to be followed by state/regional authorities, who may enforce it. The FDA states [link]: 

The Food Code is a model for safeguarding public health and ensuring food is
unadulterated and honestly presented when offered to the consumer. It represents
FDA's best advice for a uniform system of provisions that address the safety and
protection of food offered at retail and in food service.

This model is offered for adoption by local, state, and federal governmental
jurisdictions for administration by the various departments, agencies, bureaus,
divisions, and other units within each jurisdiction that have been delegated
compliance responsibilities for food service, retail food stores, or food vending
operations. Alternatives that offer an equivalent level of public health protection to
ensure that food at retail and foodservice is safe are recognized in this model.

United States TTB

The Department of the Treasury’s Alcohol and Tobacco Tax and Trade Bureau (TTB) regulates aspects of alcohol production, importation, wholesale distribution, labeling, and advertising. Unlike the FDA that is not primarily an enforcement agency, The TTB is "responsible for enforcing the laws regulating alcohol production, importation, and wholesale businesses; tobacco manufacturing and importing businesses; and alcohol labeling and advertising." [link]

But [link] "TTB does not regulate the sales of alcohol or tobacco products at the retail level... State and local authorities regulate those sales. For information about laws and regulations in your state, please contact your alcohol control board and/or local authorities."

To search the TTB, the main search box on the website is a good start [link]. A useful page is the Limited Ingredients page [link], which contains both the "Flavoring Substances and Adjuvants Subject to Limitation or Restriction" and "Flavoring Substances and Adjuvants that are Used Only in Certain Situations," which lists many ingredients that may used in alcoholic beverages only.