Part 2 of 3:

The Attachment G Opportunity

Maximizing Justifications for Intact Skin Contact Devices

This is Part 2 of a three-part series on biocompatibility justifications. Part 1 established the foundation of how FDA considers justifications. Part 3 will address complex scenarios where justifications must work harder.

A Real Opportunity in a Restrictive Landscape

Part 1 of this series established that biocompatibility justifications face significant FDA scrutiny, with many attempts failing, or raising questions because they rely on weak Tier 3 evidence. But there's one area where well-prepared justifications reliably succeed: intact skin contact devices using FDA's Attachment G.

In 2023, FDA finalized Attachment G to its biocompatibility guidance, providing a genuine pathway to skip biocompatibility testing for certain intact skin contact devices. This is one of the few areas where biocompatibility justifications reliably succeed at scale. For quality and regulatory professionals working on relevant devices, understanding Attachment G is essential.
The FDA acknowledges that medical devices in contact with intact skin comprising certain synthetic polymers or natural fabrics pose very low biocompatibility risk because they have a long history of safe use in legally marketed medical devices that contact intact skin. For these specific situations, FDA recommends including specific material information in a premarket submission in lieu of biocompatibility testing.

What Secure by Design Means In Practice

Secure-by-design is a development philosophy: security requirements are established early in design and are traceable through the development lifecycle, rather than added as a corrective measure after testing. For connected medical devices, this means cybersecurity is a design input -- governed by the same design controls process that governs functional requirements.

Practically, secure-by-design for a connected device involves three activities during design:

Threat modeling as a design control activity. Before interface specifications are finalized, manufacturers should model the threats each connection creates. What data moves across this interface? Who is authorized to initiate or receive that data? What is the consequence if this interface is compromised or behaves unexpectedly? Furthermore, does the model capture risks introduced through the software supply chain, maintenance activities, and eventual device decommissioning? Threat modeling done during design controls generates testable requirements -- not a checklist completed at submission.

Cybersecurity requirements as formal design inputs. Under FDA's Quality Management System Regulation (QMSR), which took effect in February 2026 and incorporates ISO 13485, design and development inputs must address all risk sources including cybersecurity. Authentication protocols, encryption standards, access controls, and audit logging belong in the design input specification, documented before design outputs are generated.

Defense-in-depth architecture. No single control should be treated as sufficient for a connected device. Manufacturers should design layered defenses: assume individual controls may fail, and verify that a single failure does not produce an unacceptable safety or security outcome.

What's Covered Under Attachment G

The first step in evaluating Attachment G applicability is checking whether your device and materials fall within scope.

Device Categories Covered

Attachment G applies to medical devices that contact intact skin, whether for limited or long-term duration. Examples include:

• Electrodes (ECG, EEG, EMG)

• External prostheses

• Fixation tapes and adhesive bandages

• Compression bandages (relevant to our running example)

• Wearable monitors (heart rate, glucose, activity)

• Surface application devices for diagnostic or therapeutic use

• Skin-contacting components of larger device systems

The duration of contact doesn't disqualify Attachment G use as long as contact is with intact skin only.

Materials Covered

The list of materials specifically named in Attachment G has expanded compared to earlier draft guidance, providing broader applicability:

Polymers:

• Polyethylene (PE)

• Polypropylene (PP)

• Polyethylene terephthalate (PET)

• Fluoropolymers: PTFE, expanded PTFE (ePTFE), PVDF, FEP

• Medical-grade silicones

• Polyurethanes

• Various acrylic adhesives (specifically formulated for medical use)

• Polyamides (nylon)

• Polycarbonate

• Polyvinyl chloride (medical-grade formulations)

Fabrics:

• Cotton

• Polyester

• Nylon

• Rayon

• Various blended fabrics

The list provides specific identification, not just generic categories. Reference the actual guidance document for the complete current list, as it may be updated.

Critical Exclusions That Disqualify Use

Even when your materials are listed and your device is the right type, exclusion criteria can disqualify Attachment G use. This is where many manufacturers stumble—they verify their materials are listed but miss exclusion criteria.

Contact Type Exclusions

Attachment G applies only to intact skin contact. The following contact types are excluded:

• Mucosal membrane contact: Oral, vaginal, nasal, ocular surfaces

• Breached or compromised skin contact: Wounds, ulcers, surgical sites, abrasions

• External communicating devices: Blood path, tissue/bone contact

• Implants: Any internally placed devices

This single distinction—intact versus compromised skin—completely changes the regulatory pathway, as our compression bandage example demonstrates.

Population-Based Exclusions

Specific patient populations trigger exclusions even for otherwise qualifying devices:

• Neonatal use: Devices specifically intended for newborns

• Pregnant women: Devices specifically intended for pregnant patients

These exclusions exist because these populations have different biocompatibility risk profiles, and require specific evaluation in each use case to evaluate safe use.

History-Based Exclusions

Past issues with specific materials trigger exclusions:

• Previously failed biocompatibility results for the specific material in similar devices

• Adverse biocompatibility-related clinical findings for the material in the medical device industry

If your material has a history of biocompatibility issues, even if your specific application might be safe, Attachment G doesn't apply.

Formulation Exclusions

Standard formulations qualify; novel additions don't:

• Novel additives, colorants, or processing aids not covered by standard formulations

• Specialty grades with non-standard formulations

• Composite materials with novel combinations

If your supplier's "standard" formulation includes proprietary additives that haven't been used in approved medical devices, Attachment G may not apply.

Applying Attachment G to Our Compression Bandage

Let's work through the analysis for our recurring example—the silicone-based compression bandage:

Scenario A: Limited Intact Skin Contact

Device: Single-use compression bandage for soft tissue support 
Materials: Medical-grade silicone, acrylic pressure-sensitive adhesive, polyester fabric 
Contact: Intact skin, ≤24 hours
Inclusion Criteria Check:

• Surface device, intact skin contact: ✓
  

• Materials on approved list:
  

  • Medical-grade silicone: ✓ Listed
    

  • Acrylic pressure-sensitive adhesive: ✓ Listed (standard formulation)
    

  • Polyester fabric backing: ✓ Listed
    

• Device type (compression bandage): ✓ Specifically listed

Exclusion Criteria Check:

• Mucosal membrane contact: No ✓
  

• Compromised skin contact: No ✓
  

• Previously failed biocompatibility: Verify with supplier and literature ✓
  

• Adverse biocompatibility-related findings: Verify ✓
  

• Neonatal use: No ✓
  

• Pregnant women or neonate specific use: No ✓
  

• Novel additives: Verify with supplier ✓
  

• Result: Attachment G applies. The justification approach is straightforward and likely to succeed.
  

Scenario B: Long-Term Compromised Skin Contact

Same materials, but for wound management application:

• Compromised skin contact: YES — this is a disqualifying exclusion

Result: Attachment G does NOT apply, regardless of materials. Full biocompatibility evaluation required.

The same physical product, same materials, same manufacturing—the difference between intact and compromised skin contact completely changes the regulatory approach.

Building the Attachment G Submission Package

When Attachment G applies, your submission becomes substantially simpler than full biocompatibility testing. 

Here's what you need to include:

Component 1: Complete Materials List

Document all materials in direct or indirect contact with intact skin during normal use:

"The proposed compression bandage consists of the following materials that contact intact skin during normal use:

• Medical-grade silicone, Specification: [specific grade], Supplier: [Name]

• Acrylic pressure-sensitive adhesive, Specification: [specific grade], Supplier: [Name]

• Polyester fabric backing, Specification: [specific grade], Supplier: [Name]

All raw material specifications are documented in the Device Master Record and supplier specification sheets are provided in Appendix [X]."

Component 2: History of Safe Use Statement

Document that materials have established history in cleared medical devices:

"All materials in direct or indirect contact with the patient have a documented history of safe use in legally US-marketed medical devices in contact with intact skin:

• Medical-grade silicone of this type has been used in numerous compression bandages, electrodes, and skin contact devices for over 30 years.

• Acrylic adhesives of this formulation are standard for medical adhesive products.

• Polyester fabric is commonly used in wound dressings, bandages, and external prostheses.

Specific cleared devices using these materials include K-XXXXXX (similar compression bandage), K-XXXXXX (electrode), and K-XXXXXX (bandage product)."

This can be supported by an MDR analysis or literature search demonstrating the materials' established use.

Component 3: Exclusions Confirmation

Explicitly address each exclusion criterion:

"This device does not fall under any exclusion criteria specified in Attachment G:

• Device does not contact mucosal membranes during normal use

• Device does not contact breached or compromised skin during indicated use

• No previously failed biocompatibility results exist for the materials used

• No adverse biocompatibility-related clinical findings exist for the materials

• Device is not specifically intended for neonatal use

• Device is not specifically intended for pregnant women

• Materials use standard formulations without novel additives, colorants, or processing aids"

Component 4: Quality System Documentation

Demonstrate ongoing controls beyond initial materials qualification:

• Material specifications and acceptance criteria

• Supplier qualification documentation

• Incoming material inspection procedures

• Manufacturing process controls

• Cleaning and packaging procedures

• Change control procedures

• Device Master Record maintenance plan

Component 5: Post-Market Commitments

Document ongoing obligations:

• Device Master Record annual review

• Material change control triggers

• Post-market surveillance for biocompatibility issues

• Adverse event monitoring and reporting

Total Submission Length: Typically 5-10 pages. Compared to a full biocompatibility evaluation report that can run 50+ pages with testing reports.

Anticipating Reviewer Questions

Strong Attachment G submissions proactively address questions reviewers commonly ask:

Material Consistency Over Time: Document supplier qualification procedures, incoming material inspection, and change control protocols that maintain material consistency.

Supplier Changes: Explain change control procedures that trigger re-evaluation against Attachment G criteria when suppliers change.

Post-Market Issue Detection: Describe complaint handling procedures, post-market surveillance approach, and adverse event reporting that would identify any emerging biocompatibility concerns.

Manufacturing Process Effects: Even though materials are on the approved list, briefly address that your manufacturing process doesn't introduce contaminants or modifications that would affect biocompatibility.

When to Consider a Q-Submission

Some situations warrant FDA consultation before relying on Attachment G:

• Borderline material formulations: Standard polymer with non-standard additives

• Combination of approved materials in novel configuration: Multiple Attachment G materials combined in ways not previously approved

• Edge cases in device classification: Devices that might be classified as something other than what Attachment G covers

• Materials at the edge of the approved list: Specific grades or formulations not explicitly addressed

The Q-Submission process provides FDA feedback within 75-90 days. For Attachment G ambiguity, this consultation may prevent submission rejection.

The Strategic Value of Attachment G

For manufacturers developing intact skin contact devices, Attachment G represents substantial value:

Cost Savings: Avoiding biocompatibility testing can save $25,000-$60,000 per device type, often more for devices requiring extensive endpoint testing.

Timeline Acceleration: Eliminating 3-6 months of testing time accelerates time-to-market significantly.

Reduced Complexity: 5-10 page submissions vs. 50+ page biocompatibility reports simplify regulatory work and review.

Risk Mitigation: FDA's published exemption reduces submission risk compared to building novel justifications.

Strategic Material Selection

For new device development, Attachment G applicability should be a deliberate consideration in material selection:

• When material choices are otherwise equivalent, prefer Attachment G-listed materials

• Document material decisions to demonstrate Attachment G considerations

• Maintain supplier relationships for approved materials to support ongoing compliance

• Build internal material lists prioritizing Attachment G compatibility

   

Key Takeaways from Part 2

1. Attachment G is a real opportunity for intact skin contact devices, but applicability is narrower than many manufacturers assume.

2. Both inclusion AND exclusion criteria matter—material being on the list is necessary but not sufficient.

3. Contact type drives applicability: Intact skin enables Attachment G; mucosal membrane or compromised skin disqualifies it.

4. The submission package is dramatically simpler: 5-10 pages with materials list, history statement, exclusions confirmation, quality documentation, and post-market commitments.

5. Strategic material selection with Attachment G in mind creates regulatory value for new device development.

Coming Up in Part 3

Part 3: When Justifications Must Work Harder—We'll address what happens when Attachment G doesn't apply. The wound management scenario for our compression bandage requires fundamentally different approaches:

• Chemical characterization strategy under ISO 10993-18

• Toxicological risk assessment under ISO 10993-17
  

• Leveraging Master Access Files from material suppliers
  

• Using your own prior cleared devices for partial justifications
  

• Common failure modes and how to avoid them
  

• Decision framework for testing vs. justification tradeoffs

The same materials in our compression bandage—but in wound management application—will require 60-130 pages of documentation including multiple test reports. Understanding how to navigate this complexity is essential for quality and regulatory professionals working on devices outside Attachment G's scope.