Aquafaba is the viscous water in which legumes (usually chickpeas aka garbanzo beans) have been soaked. In food and beverages, aquafaba can be used as a vegan substitute for egg whites.
Some people are allergic to chickpeas/garbanzo beans as part of a legume allergy that includes peanuts and beans. Not all customers will know that the term "aquafaba" refers to chickpea water. Bartenders should consider labelling aquafaba explicitly as "chickpea water" or adding a note somewhere on the menu that aquafaba is chickpea water. If a customer alerts staff to a peanut allergy, caution should be taken to inquire about legumes/aquafaba.
We are not aware of any current safety regulations over the use of aquafaba after reviewing the US FDA website.
Some home cooks have expressed concerns over BPA coating inside cans that chickpeas are often sold in, as well as concern about saponins.
"Saponins are bitter compounds that are naturally present in quinoa—along with lots of other foods, including a wide variety of legumes, vegetables, and herbs. They get their name because they lather up in water, like soap suds." [link] "Saponins are glycosides with a distinctive foaming characteristic. They are found in many plants, but get their name from the soapwort plant (Saponaria), the root of which was used historically as a soap" [link] In cocktails, the saponins are the thing we're after to make egg white-like foam.
However, the United States EPA addressed saponins, specifically when studying soap bark (quillaja saponaria) [link]:
Food. The Agency is not concerned about dietary exposure to Quillaja saponins because humans consume it regularly without any reports of adverse effects. Humans are regularly exposed to Quillaja saponins via their use as an FDA-approved flavoring agent and food additive. Undiluted Quillaja saponaria extracts are used in soft drinks at levels of 100-500 mg/kg (WHO, 2002). The Joint WHO/FAO Expert Committee on Food Additives (WHO, 2002) established an acceptable daily intake (ADI) of Quillaja saponins of up to 5 mg/kg/day. The mean intake of Quillaja extracts in the U.S. just from soft drinks (the major food use) is as much as 0.54 mg/kg/day, or 11% of the ADI (WHO, 2006). According to EPA's review and calculations using a maximum use rate for up to 6 applications per season, the exposure and average daily intake of Quillaja saponins from treated crops is estimated to be 0.28 mg/kg bwt. This amount is well below the established ADI of 5 mg/kg bwt (WHO, 2002). Even if the use of Quillaja saponins exceeds the maximum proposed use rate, the Agency is not concerned about dietary exposure because of the low toxicity of this active ingredient and the history of its use without any reports of adverse effects.
"What Exactly Is Aquafaba, and How Do I Use It?" America's Test Kitchen [link]
Soap Bark (CocktailSafe)