Cannabinoids are chemical compounds that naturally occur at various levels in all species of Cannabis Sativa L. (Hanuš et al., 2016). However, since the passage of the 2018 Farm Bill in the United States (US), Cannabis Sativa L. and its derived cannabinoids can be legally classified as either “hemp” or “marijuana” based on their concentration of delta-9-tetrahydrocannabinol (delta-9-THC), with plants or derivatives containing ≤ 0.3 % delta-9-THC considered “hemp” and those with > 0.3 % delta-9-THC considered “marijuana” (i.e., cannabis) (Agriculture and T.U.S.S.C.O. , 2018). A critical drug policy question is whether it is legal to sell cannabinoids derived from hemp to produce psychotropic chemical analogs to delta-9-THC, such as ${\mathrm{\Delta }}^8$ tetrahydrocannabinol (delta-8-THC) (Dickson et al., 2019). Many manufacturers have interpreted the 2018 Farm Bill as implying that hemp and marijuana derivatives are legal so long as they contain ≤ 0.3 % delta-9-THC. However, the Drug Enforcement Agency has refuted this assumption in some communications but has yet to take broad-sweeping actions against hemp and marijuana derived product manufacturers (Leas, 2021). This legal ambiguity about products like delta-8-THC has created a new market for ‘derived’ cannabinoid products in the US (Kruger and Kruger, 2021, Kruger and Kruger, 2022, Leas et al., 2022, Livingston et al., 2022, Rossheim et al., 2023, Rossheim et al., 2022).

The availability of derived cannabinoid products in inhalable modalities, such as vapes, has created regulatory complexities that overlap with tobacco regulation. Almost all retailers in Fort Worth, Texas with an alcohol, tobacco, or cannabidiol (CBD) license that sold delta-8-THC (96 %) offered product types that were intended to be smoked or vaped (Rossheim et al., 2022). Furthermore, an assessment of online retailers of psychotropic cannabinoid products showed that most of the modalities offered were inhalable, such as disposable vapes (43 %), vape carts (18 %), and pre-rolls (7 %) (Rossheim et al., 2024b). The overlap in modes of use between tobacco and cannabinoid products can interfere with efforts to pinpoint culprit products during vaping-related outbreaks, such as the e-cigarette or vaping-associated lung injuries outbreak, in which many cases vaped a combination of cannabinoid and tobacco products (Blount et al., 2020, Heinzerling et al., 2020). Although tobacco product manufacturers are required to submit product applications to the Food and Drug Administration (FDA) before they can market and distribute them in the US, the FDA does not have a similar framework for derived cannabinoid products. Nevertheless, the FDA has taken some actions to protect public health by issuing warning letters to companies marketing inhalable CBD products and delta-8-THC products (Wagoner et al., 2021). The interchangeability of vaping products can also create loopholes in regulation. For example, although several US states have banned flavored nicotine vapes to tackle nicotine vaping among youth, similar regulations for derived cannabinoid products are rare (Egan et al., 2023), even though cannabinoid product use is prevalent among US youth (Harlow et al., 2024).

The lack of quality and safety standards for derived cannabinoid products may also have public health impacts. Without established quality assurance standards, derived cannabinoid products can be mislabeled, may include more than 0.3 % delta-9-THC, and may include harmful contaminants (Gidal et al., 2024, Meehan-Atrash and Rahman, 2021). For example, one assessment of commercially available CBD products in the US found that most (74 %) of these products were inaccurately labeled, and several contained heavy metals, residual solvents, and pesticides that violated regulatory thresholds (Gidal et al., 2024). Similarly, a toxicological analysis of 27 vaping products containing delta-8-THC found that all of the products had mislabeled the delta-8-THC content contained and contained side-products such as heavy metals, and many products contained unlabeled cutting agents (Meehan-Atrash and Rahman, 2021). There were over 2,000 reports of adverse events linked to delta-8-THC consumption received by the FDA and the National Poison Control Centers between December 2020 and February 2022, many of which required medical intervention and involved pediatric patients (Administration, 2022, Simon et al., 2023, Staff, 2021). Many of the symptoms presented in adverse events related to delta-8-THC use were similar to those reported for acute delta-9-THC intoxication (e.g., anxiety and paranoia), but there were several unique symptoms that could have stemmed from unregulated manufacturing methods (e.g., muscle spasms) (Leas et al., 2023a).

Given the existing regulatory challenges and health risks associated with derived cannabinoid products, very little is known about how vape shops, specifically those with an online presence, have responded to their growing popularity. Prior research has already shown that tobacco retailers, including vape shops, often sell substances other than nicotine, including kratom, CBD, and delta-8-THC (Bowdring et al., 2023, Kruger and Kruger, 2021, Leas et al., 2021, LoParco et al., 2023, Rossheim et al., 2022). A recent review of 520 vape shops across the US found that 74 % offered psychotropic cannabinoid products for sale (Rossheim et al., 2024). Despite local regulations for flavored tobacco products (Leas et al., 2023b), online vape shops may be introducing inhalable cannabinoid products with characterizing flavors as a new substance that is appealing to youth, even though they may pose increased short-term risks. Online retailers, which frequently use e-commerce platforms, are often not included in the definition of “retailers” within local and state policies governing tobacco products (Leas, 2024). Therefore, online retailers may operate across state lines, potentially avoiding local regulations, such as state bans on flavored tobacco products. There are jurisdictions in which online retailers are subject to laws governing certain products. For example, California’s Assembly Bill 45 prohibits the manufacture or sale of inhalable industrial hemp products (i.e., cannabis plants containing $\le$ 0.3 % delta-9-THC), including retailers that offer products through a delivery service (i.e., e-commerce), except for the sole purpose of sale in other states. As a part of this law, inhalable industrial hemp products, including those sold across state lines, cannot contain characterizing flavors other than natural terpenes, may not be sold to consumers under 21 years of age, and may not be sold in retail locations in California (AB45, C., 2021). However, to our knowledge, no surveillance of flavored and inhalable cannabinoid products to inform enforcement activity has been conducted.

To inform policy around cannabinoid products, we describe the availability of derived cannabinoid products in online tobacco retailers in California. Furthermore, we evaluate compliance with a local law that restricts flavored and inhalable hemp product sales. Since vape shops may be offering derived cannabinoid products as a way of generating business, we used web traffic data for the websites in our study sample to compare traffic according to whether they offer derived cannabinoid products or not.