Navigating FDA Warning Letters in the ENDS Industry

FDA warning letters remain one of the most visible enforcement tools used in the Electronic Nicotine Delivery Systems (ENDS) industry. While these letters are publicly accessible and often widely circulated, they are frequently misunderstood, both in terms of what they signal and how companies should respond.

This article provides practical context on how FDA warning letters arise, what they typically reflect about a company's compliance posture, and how ENDS manufacturers can approach response and remediation in a structured, risk-based manner.

What an FDA Warning Letter Represents

A warning letter is not a final enforcement action, but it is also not informal feedback. It signals that FDA believes a company is in significant violation of applicable regulatory requirements and that previous opportunities for correction have either been insufficient or unsuccessful.

In the ENDS context, warning letters most commonly relate to:

• •Marketing products without authorization
• •Failure to submit or maintain required PMTA documentation
• •Inadequate manufacturing or quality controls
• •Distribution of products that differ from those reviewed by FDA

Importantly, a warning letter reflects FDA's interpretation based on the information available at the time. It does not necessarily imply intent, but it does indicate regulatory risk that must be addressed.

Common Themes in ENDS Warning Letters

Although the language of warning letters varies, several recurring themes appear across ENDS enforcement actions.

Marketing and Authorization Gaps

Many letters cite the marketing of products without an authorized PMTA or outside the scope of an existing submission. This includes product variations, component changes, or new SKUs that were not explicitly covered.

Manufacturing and Quality System Deficiencies

FDA frequently raises concerns when manufacturing practices are poorly documented or inconsistently implemented. Common issues include inadequate process controls, insufficient documentation, and weak traceability between components and finished products.

Misalignment Between Submission and Commercial Product

Differences between the product described in a PMTA and the product actually being manufactured or sold are a frequent driver of enforcement. Even seemingly minor changes can raise concerns if they are not evaluated and justified.

Why Warning Letters Often Catch Companies Off Guard

Warning letters often feel sudden to recipients, but they rarely occur in isolation. In many cases, they follow a pattern that includes:

• •Informal inquiries or inspection observations
• •Deficiency letters or information requests
• •Extended periods without documented corrective action

From FDA's perspective, a warning letter often represents an escalation after earlier signals were not adequately addressed.

Responding to a Warning Letter: A Structured Approach

An effective response requires more than a point-by-point rebuttal. FDA expects a demonstration of understanding, ownership, and sustainable correction.

Key elements of a strong response typically include:

• •A clear acknowledgment of the cited issues
• •A root-cause analysis rather than surface-level fixes
• •Specific corrective and preventive actions
• •Defined timelines and accountability

Overly defensive responses or vague commitments tend to invite further scrutiny rather than resolve it.

The Role of Documentation and Change Control

Many ENDS warning letters ultimately trace back to gaps in documentation and change management. FDA places significant weight on whether companies can demonstrate:

• •Control over their manufacturing processes
• •Traceability between materials, components, and finished goods
• •A structured approach to evaluating design or process changes

Strong documentation does not eliminate risk, but it provides credibility and context when questions arise.

Warning Letters as an Opportunity

While warning letters are serious, they also present an opportunity to reset regulatory posture. Companies that respond thoughtfully often emerge with:

• •Clearer internal processes
• •Better alignment between development, manufacturing, and regulatory teams
• •Reduced long-term compliance risk

The goal is not simply to close the letter, but to prevent recurrence.

Final Thoughts

In the ENDS industry, FDA warning letters are rarely about a single mistake. They typically reflect systemic gaps that have accumulated over time.

Understanding how these letters arise, and responding with disciplined, technically grounded remediation, is essential for companies seeking long-term regulatory stability. A proactive approach to compliance, documentation, and change management remains the most effective way to reduce enforcement risk.