Image credits: Dr. Beth Ripley and Timothy Prestero.

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COVID 3D TRUST: Frequently Asked Questions

Curated by NIH/NIAID in collaboration with the U.S. Food and Drug Administration, the Veterans Healthcare Administration, and America Makes

We are continuing to add content regularly. Please use the contact form to reach out for more information that can be provided here.

About this Initiative

What is the purpose of this collection and how did it come about?

The COVID-19 Supply Chain Response collection emerged from established collaborative relationships among the FDA, NIH, VA, and America Makes, and was built on a common shared interest in addressing the shortage of PPE and medical devices during the COVID-19 public health emergency.

The objectives of the initiative are two-fold:

  1. Test and validate designs for devices that can be used in a clinical setting, so that manufacturers with capabilities in 3D printing/additive manufacturing (3DP/AM) may fill gaps in the supply chain at a large scale. The nature of 3DP/AM technology makes it well-suited to rapidly switching production to new products, as it does not require the significant shift in processes necessary in injection molding, or in machining methods used in traditional subtractive manufacturing.
  2. Support the global community of Makers and 3D printing enthusiasts to better understand the aspects of design and materials that feature in the usability and safety of 3D-printed PPE and other devices needed by healthcare workers and the community at large.

The ultimate goal of the partnership is to inform decision-making on PPE and medical device production, without stifling innovation. With the growing number of open source designs available, we aim to enable rapid response by filtering designs through a systematic review process. The testing criteria are informed by standards from the FDA, CDC, and NIOSH, and best practices for 3D printing methods and experience with medical device development.

What are the participating organizations?

  • The NIH 3D Print Exchange, a resource from the National Institute of Allergy and Infectious Diseases, is hosting this collection to designate designs related to COVID-19 supply shortages, which have tried and tested by engineers and clinicians. The Exchange is an open repository for finding, sharing, and creating 3D-printable models related to bioscience, medicine, and related open hardware designs.
  • The U.S. Food & Drug Administration is striving to facilitate the use of this and other advanced manufacturing technology to bring PPE and other needed medical device parts to healthcare organizations through emergency use authorization. Manufacturers who have questions about helping during this pandemic can reach out to the FDA at
  • The VA Innovation Ecosystem includes many hospitals and clinics in the Veterans Affairs healthcare network that have 3D Printing design and engineering expertise. Many designs shared in this collection have been designed or tested by engineers and clinicians in the VA Innovation Ecosystem. Learn more at the VHA 3D Printing Network COVID-19 Response site.
  • America Makes is a public-private partnership with member organizations from industry, academia, government, non-government agencies, and workforce and economic development resources, aimed at innovating and accelerating 3D printing and additive manufacturing (AM) technology to increase our nation’s global manufacturing competitiveness. The role of America Makes as a partner in the COVID-19 supply chain response initiative is to be the bridge connecting the needs of health care providers with manufacturers capable of 3D printing much needed supplies. If you are a manufacturer, or a healthcare facility in need of supplies, visit the America Makes COVID-19 response site to learn more.

What are the categories for the models in this collection, and what do they mean?

  • All submissions related to PPE and medical devices during the COVID-19 public health emergency are automatically tagged as a Prototype. Prototypes may not have been reviewed, and as such the reviewers from the VA Innovation Ecosystem are unable to recommend them for use, so users should exercise their best judgement in deciding to use these designs over other. Exceptions to this initial tagging are models that (a) require FDA approval or emergency use authorization, or are associated with health and safety risks; (b) models that have already been submitted for FDA approval; and (c) designs that already have FDA emergency use authorization.
  • Community Use is not a formal designation in classifying PPE, but we are using this term to indicate designs suitable for workers in grocery stores, restaurants, law enforcement, or in general use interacting with others. Community use designs have been tested for fit, efficiency, and reliability when the wearer is not in direct contact with a person diagnosed or suspected of having COVID-19.
  • Designs with Clinical Review status have been printed by the VA Innovation Ecosystem team and evaluated in a clinical setting. These devices do not require approval by the FDA, CDC, or NIOSH. They should, however, be made accroding to best practices for quality in the printing process and in selection of materials, and follow instructions provided with each design carefully through the process.
  • Submitted for FDA Review: Designs in this category are under review for Emergency Use Authorization by the FDA. Unless otherwise specified, they have not been reviewed through the VA Innovation Ecosystem team or their partners. These devices require FDA approval, and should not be used until passing that process.
  • FDA Emergency Use Authorization indicates that the device has temporary allows for use of particular devices during the COVID-19 public health emergency. Emergency Use Authorization still requires that manufacturers adhere to the applicable standards for quality control and assurance, in facilities that meet the FDA's Good Manufacturing Practices regulations.
  • Designs with a "Warning" label are those that require FDA approval for use and/or by the nature of their design or application could introduce risks to health and safety.

Is content on the site "Approved" by the NIH?

No, models hosted on the NIH 3D Print Exchange are not approved for any specific use, and designs found on the site should not be considered as "NIH Approved." 

However, models in the COVID-19 collection may be reviewed and tested in a clinical setting by partners in the Veterans Health Administration and other collaborating institutions. These are designated as "Clinically Reviewed" and for "Community Use." Unless otherwise specified, designs are not approved by the FDA. 

3D printing processes vary widely, so the same design may be produced in hundreds of different ways, depending the type of printer, materials, print settings, and post-processing steps. For that reason, the NIH, VA, FDA, America Makes, collaborating partners, and content contributors are not liable for any injury or other personal harm that may arise from 3D printed PPE, medical devices, or other hardware (such as laboratory equipment) produced based on 3D designs found in the NIH repository. See the Terms and Conditions of our website for additional information. 

Device Safety

What is the difference between disinfection and sterilization?

In short, sterilization destroys all microorganisms, while disinfectants destroy microorganisms to a lower and varying level of degree. The FDA defines disinfection as:

"a process that destroys pathogens and other microorganisms by physical or chemical means. Disinfection processes do not ensure the same margin of safety associated with sterilization processes. The lethality of the disinfection process may vary, depending on the nature of the disinfectant, which leads to the following subcategories: 

  • High Level Disinfection: A lethal process utilizing a sterilant under less than sterilizing conditions. The process kills all forms of microbial life except for large numbers of bacterial spores 
  • Intermediate Level Disinfection: A lethal process utilizing an agent that kills viruses, mycobacteria, fungi and vegetative bacteria, but no bacterial spores. 
  • Low Level Disinfection: A lethal process utilizing an agent that kills vegetative forms of bacteria, some fungi, and lipid viruses. 

In contrast, sterilization is "a validated process used to render a product free from viable microorganisms. The survival of a microorganism on an individual item can be expressed in terms of probability. While this probability can be reduced to a very low number, it can never be reduced to zero.”

See FDA Guidance “Reprocessing Medical Devices in Health Care Settings: Validation Methods and Labeling.” 

How can we ensure our 3D printed devices are safe to use?

COVID 3D TRUST cannot guarantee the safety of the final 3D printed products from any specific manufacturer or source, however the design files categorized for community or clinical use in COVID 3D TRUST have been assessed for efficacy, appropriateness, and usability for their intended use when manufactured as instructed based on the accompanying documentation. Users should exercise best judgement in the process of design selection and printing.

Many of the designs in COVID 3D Trust are either currently covered (as of 19-March-2021) by blanket FDA EUA’s, FDA Guidance for the COVID public health emergency, or are not considered medical devices. Manufacturers and end users should verify that the EUA is still active prior to taking any action:

General considerations when printing medical products can be found in the FDA Technical Considerations for Additive Manufacture Medical Devices 

While this is not an exhaustive list of considerations, this document contains a collection of general guidance and best practices. Each particular application or product will need to undergo its own testing or evaluation prior to use.

FDA Guidelines and Approval

What is the FDA's enforcement policy?

In April 2020, the FDA released a statement on its Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency

The summary scope of that guidance states:

FDA recognizes that, when alternatives, such as FDA-cleared masks or respirators, are unavailable, individuals, including healthcare professionals, might improvise PPE. FDA does not intend to object to individuals’ distribution and use of improvised PPE when no alternatives, such as FDA-cleared masks or respirators, are available.

What does "Labeling" Mean?

“Labeling” refers to the information that is provided on the packaging or the product itself.  

For 3D printed PPE during the COVID public health emergency, best practice for labeling includes but is not limited to the following:

  • Article Name – The name of the product on the NIH 3D Print Exchange, often the build file name or name of the model
  • Type of use – Clinical, or community use
  • Material – The name of the material(s) from which the print is produced
  • Instructions for Use (IFU) – Often this is a link back to the NIH 3D Print Exchange to where the usage instructions and other documentation can be found.

Label is defined in the Federal Food, Drug and Cosmetic Act (FFDCA) in Section 201(k), “means a display of written, printed, or graphic matter upon the immediate container of any article.” Labeling is defined in that same Act under Section 201(m), “means all labelsand other written, printed, or graphic matter (1) upon any article or any of its containers or wrappers, or (2) accompanying such article.”

For more information see the FDA Website:

How does the FDA define face masks, shields, and respirators?

Face Mask – A mask, with or without a face shield, that covers the user’s nose and mouth and may or may not meet fluid barrier or filtration efficiency levels.

Face Shield - A face shield is a device used to protect the user's eyes and face from bodily fluids, liquid splashes, or potentially infectious materials. Generally, a face shield is situated at the crown of the head and is constructed with plastic to cover the user’s eyes and face.

Surgical Mask – A mask that covers the user’s nose and mouth and provides a physical barrier to fluids and particulate materials. The mask meets certain fluid barrier protection standards and Class I or Class II flammability tests.

Filtering Facepiece Respirator – A filtering facepiece respirator (FFR) is a device that is a disposable half-face-piece non-powered air-purifying particulate respirator intended for use to cover the nose and mouth of the wearer to help reduce wearer exposure to pathogenic biological airborne particulates.

N95 Respirator – A disposable half-mask filtering facepiece respirator (FFR) that covers the user’s airway (nose and mouth) and offers protection from particulate materials at an N95 filtration efficiency level per 42 CFR 84.181. Such an N95 FFR used in a healthcare setting is regulated by FDA under 21 CFR 878.4040 (FDA product code MSH) and is either a class II device that is exempt from premarket notification requirements under section 510(k) of the FD&C Act or is a class II cleared device.

NIOSH Approved N95 Respirator – An N95 respirator, approved by NIOSH that meets filtration efficiency level per 42 CFR 84.181. NIOSH is the National Institute for Occupational Safety and Health.

Surgical N95 Respirator – A disposable FFR used in a healthcare setting that is worn by HCP during procedures to protect both the patient and HCP from the transfer of microorganisms, body fluids, and particulate material at an N95 filtration efficiency level per 42 CFR 84.181. A surgical N95 respirator is regulated by FDA under 21 CFR 878.4040 (FDA product code MSH) and is either a class II device that is exempt from premarket notification requirements under section 510(k) of the FD&C Act or is a class II cleared device.

Source: FDA Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency (Revised), page 4. Accessed 4/13/2020.

If I make PPE for community use, do I need to adhere to Labeling guidelines?

For products that are not regulated by the FDA, “Labeling” in the official sense is not required. However, it a best practice and a courtesy to the end user to provide them information on what is being provided, whether it is being sold or donated.

For 3D printed PPE, best practice for labeling includes but is not limited to the following:

  • Article Name – The name of the product on the NIH 3D Print Exchange, often the build file name or name of the model
  • Type of use – Clinical, or community use
  • Material – The name of the material(s) from which the print is produced
  • Instructions for Use (IFU) – Often this is a link back to the NIH 3D Print Exchange to where the usage instructions and other documentation can be found.

Are 3D-printed face masks regulated by the FDA?

The manufacture of face masks for non-medical purposes is not regulated by the FDA, but there may be local standards that apply based on where they are used, e.g., state or county.

The intended use and performance claims of the 3D-printed face mask will determine if it is regulated by the FDA. For specifics, see FDA Guidance “Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency (Revised)”

Are designs on this site FDA Approved?

No. Unless specifically indicated on the model page, 3D-printable files hosted on the NIH 3D Print Exchange are not FDA Approved. In some cases, the FDA may clear devices with an "Emergency Use Authorization" that temporarily allows for use of particular devices during the COVID-19 public health emergency. Emergency Use Authorization still requires that manufacturers adhere to the applicable standards for quality control and assurance. 

Information About PPE and Devices

What is an IFU (Instructions for Use) document?

An Instructions For Use (IFU) document should contain detailed, action-oriented, step-by-step written and visual instructions provided in a patient-friendly manner. IFUs may be provided for designs hosted in the COVID-19 collection and elsewhere on the NIH 3D Print Exchange, but unless otherwise specified should not be considered as meeting the full requirements for an IFU.

Usually whomever is responsible for the product develops the labeling, however there are some exceptions. Whether the FDA reviews or approves the labeling depends on the classification of the product. The FDA does not review or approve labeling for for Class I or 510(k) exempt products, but the labeling should still needs to meet requirements (unless it is exempt).

What is the difference between a face mask and a respirator?

  • General use face masks protect the wearer from physically contaminating their mucous membranes (mouth and nose) with virus on their hands. These are not intended for use by health care professionals in a health care setting. These may or may not meet fluid barrier or filtration efficiency levels.
  • A surgical mask is a loose-fitting, disposable device that creates a physical barrier between the mouth and nose of the wearer and potential contaminants in the immediate environment. These are often referred to as face masks, although not all face masks are regulated as surgical masks. Note that the edges of the mask are not designed to form a seal around the nose and mouth.Surgical face masks are specifically designed for a health care setting, and they carry the important distinction of being able to provide a physical barrier from fluids and particulate materials.They protect the wearer from large droplets, splashes, or sprays of bodily or other hazardous fluids, but do not protect against inhaling smaller airborne particles, such as might be transmitted by coughs, sneezes or certain medical procedures. These are usually loose-fitting around the edges of the mask and do not require a tight seal.
  • N95 Respirators offer our front line health care providers all the protections of surgical face masks but additionally offer protection from the inward leakage of small aerosolized particles into the mask at a higher efficiency level. These require a tight seal, so there is minimal leakage of air around the edges of the mask when the wearer breathes in. The CDC does not recommend that the general public wear N95 respirators.

What is an N95 respirator?

An N95 respirator is a respiratory protective device designed to achieve a very close facial fit and very efficient filtration of airborne particles. The 'N95' designation means that when subjected to careful testing, the respirator blocks at least 95 percent of very small (0.3 micron) test particles. If properly fitted, the filtration capabilities of N95 respirators exceed those of face masks. However, even a properly fitted N95 respirator does not completely eliminate the risk of illness or death.

Most N95 respirators are manufactured for use in construction and other industrial type jobs that expose workers to dust and small particles. They are regulated by the National Personal Protective Technology Laboratory (NPPTL) in the National Institute for Occupational Safety and Health (NIOSH), which is part of the Centers for Disease Control and Prevention (CDC)

However, some N95 respirators are intended for use in a health care setting. Specifically, single-use, disposable respiratory protective devices used and worn by health care personnel during procedures to protect both the patient and health care personnel from the transfer of microorganisms, body fluids, and particulate material. These surgical N95 respirators are class II devices regulated by the FDA, under 21 CFR 878.4040, and CDC NIOSH under 42 CFR Part 84.

N95s respirators regulated under product code MSH are class II medical devices exempt from 510(k) premarket notification, unless:

  • The respirator is intended to prevent specific diseases or infections, or
  • The respirator is labeled or otherwise represented as filtering surgical smoke or plumes, filtering specific amounts of viruses or bacteria, reducing the amount of and/or killing viruses, bacteria, or fungi, or affecting allergenicity, or
  • The respirator contains coating technologies unrelated to filtration (e.g., to reduce and or kill microorganisms).

The FDA has a Memorandum of Understanding (MOU) with CDC NIOSH which outlines the framework for coordination and collaboration between the FDA and NIOSH for regulation of this subset of N95 respirators.

For additional differences between surgical masks and N95 respirators, please see CDC’s infographic and the FDA's informatonal page about N95 respirators and surgical masks.


What is the efficiency level of N95 respirators?

Per 42 CFR 84.181 – N95 respirators have 95% filter efficiency (block 95% of very small 0.3 micron particles). 

Can I reuse a surgical mask, respirator, or other PPE?

No, surgical masks and respirators should not be shared or reused, according to FDA guidelines (Updated 3/11/20; accessed 4/6/20). However, during the COVID-19 PPE supply shortage, the CDC has issued guidance on Strategies for Optimizing the Supply of Facemasks (Updated 3/17/20; accessed 4/13/20).

In general, most PPE is designed to be used only one time and by one person prior to disposal. There are a few exceptions, for example some types of elastomeric respirator masks and protective eyewear such as goggles may be reused if the user follows decontamination methods in the product labeling.

If PPE is exposed to infectious materials during use (e.g., body fluids from an infected person) the PPE is considered contaminated and the wearer should remove it promptly, using proper removal and disposal procedures. Please be aware that even if a PPE successfully protects you while it is being worn, improper removal and disposal of contaminated PPEs can expose the wearer and other people to infectious agents.

Are there any general precautions in using N95 respirators?

People with chronic respiratory, cardiac, or other medical conditions that make breathing difficult should check with their health care provider before using an N95 respirator because the N95 respirator can make it more difficult for the wearer to breathe. Some models have exhalation valves that can make breathing out easier and help reduce heat build-up. Note that N95 respirators with exhalation valves should not be used when sterile conditions are needed.

All FDA-cleared N95 respirators are labeled as "single-use," disposable devices. If your respirator is damaged or soiled, or if breathing becomes difficult, you should remove the respirator, discard it properly, and replace it with a new one. To safely discard your N95 respirator, place it in a plastic bag and put it in the trash. Wash your hands after handling the used respirator.

N95 respirators are not designed for children or people with facial hair. Because a proper fit cannot be achieved on children and people with facial hair, the N95 respirator may not provide full protection.

What should health care providers do if using a 3D-printed mask?

Health care providers should:

  • Check the 3D-printed mask's seal for leaks.
  • Confirm that they can breathe through any makeshift filter materials.
  • Exercise caution in surgical environments where the need for liquid barrier protection and flammability is a concern.
  • Recognize that the mask may not provide air filtration enough to prevent transmission of infectious agents.
  • Safely dispose of infectious materials and disinfect any part they intend to reuse.

Source: FDA FAQs on 3D Printing of Medical Devices, 04/05/2020

Will 3D printed PPE provide the same protection as traditional masks and respirators?

3D-printed masks may look like conventional PPE. However, when printed with a desktop 3D printer, especially a fused-deposition modeling (FDM) printer, they may not provide the same level of barrier protection, fluid resistance, filtration, and infection control. 3D-printed devices from commercial printers operated in a facility adhering to best practices in quality control and quality assurance, may provide the same level of protection as traditional PPE products. 

Submission and Review Process

What is the evaluation process for surgical mask proposals?

In addition to the criteria outlined for face masks, additional tests used for evaluating surgical mask design proposals include:


  1. Fluid resistance testing: This test evaluates the liquid barrier protection provided by the face mask and is conducted with a protocol equivalent to the ASTM F1862 standard. Bottom line: Does it stop blood and other bodily fluids from passing through the mask?
  2. Flammability resistance evaluation: The device must pass Class I or Class II flammability requirement per 16 CFR 1610, or specific labeling must be included to instruct the user to avoid high heat and open flame while using this device.
  3. Adequate air exchange testing: The device is tested to measure the air flow it provides to the user by following the protocol outlined in the MIL-M-36945C standard or by testing the device during simulated clinical scenarios where multiple users complete a 2 minute round of CPR while wearing the mask. Bottom line: you don’t want to become hypoxic while wearing your mask.
  4. Bacterial filtration efficiency: How well can the mask stop aerosolized bacteria? ASTM F2101.
  5. Sub-micron particulate filtration: ASTM F2299.

What is the evaluation process for general use face mask proposals?

When reviewing face masks for general use, the VA Innovation Ecosystem seeks to answer the following questions:

  1. Is there appropriate documentation to describe how the device should (and should not) be used?
  2. 3D printability test: is there enough information provided for someone to understand the type(s) of 3D printer, the printer settings, and the appropriate materials to use? If non-3D printed parts are required, is there a clear list of materials that the maker/manufacturer needs to buy?
  3. Assembly test: Is there enough information provided for someone to properly assemble all of the components? (Think Ikea-style diagrams, etc.)
  4. Durability testing: Will the mask hold up to repeated use, such as putting it on and taking it off multiple times, without breaking or falling apart?
  5. Adequate airflow assessment: Can the wearer breath comfortably when wearing the mask? Specifically, can the wearer walk for 2 minutes with the mask on, and not feel like it is hard to breathe?
  6. Sizing/fit evaluation: Does the mask conform reasonably well to an average user’s face? Are there large gaps or poor sizing over facial features such as the nose bridge? Is the fit good enough that the majority of air being breathed passes through the filter component when used?

How do I submit a model to the site?

We request you provide as much detail as possible in your design submission, and in your user profile. Not all entries will be reviewed, but entries without sufficient information will not be considered. Exact specifications are encouraged. A PDF with step-by-step instructions is availble here. For further information, you can reach out to us via the site contact form.

Which designs are tested, and in what order?

We want to let you know what our process is for prioritizing clinical testing. Each submission is given a score that determines where in the queue they are for testing. This score includes the following criteria:

1. Demand- is this an item that has been identified in the community and/or logistics supply chains as in short supply or at risk of running out?

2. Feasibility- Is this design printable as described, and does the design look like it will reasonably work as described?

3. Detail- Is the submission complete, with detailed instructions on how to print the part and how to use the part?


What happens if a design is evaluated and it does not pass?

If we find design flaws or other concerns when reviewing a prototype, a member of the device review team will reach out to the user by email to give constructive feedback. Our goal is to help get you to a successful design. After iteration, the reviewing team(s) will re-evaluate and if you have addressed the concerns successfully, and we will move the design to the appropriate category.  

What can I do to speed up the review process of my proposal?

Due to the growing number of submissions, the VA and its collaborating reviewers cannot guarantee that all designs will be reviewed, and there is no process to "fast-track" any reviews. Note that the NIH 3D Print Exchange team does not play a role in the selection or review process. Please do not contact us to inquire.

Designs that have been marked “Reviewed for clinical use” are a great resource for understanding what good documentation looks like. In general, you want to provide information about what type of printer your design should be printed on, what types of materials should be used, what the clinical indications of the design are, and how the design should be constructed and used.

I uploaded my design, now what?

Thanks for sharing! At present, all entries will be automatically tagged in the "Prototype" stage. Administrators may modify this prior to review if the design is for a device that could have safety risks, such as ventilator parts.

Site administrators and partners at the VA will look at new models and prioritize designs for testing.

  • Designs without sufficient detail of information will not be reviewed. In some cases, admins or reviewers may reach out to you for additional information.
  • It is helpful to have information about yourself in your user profile, so that reviewers and users have an idea from where/whom the design is coming.

Designs that have been reviewed in the VA Innovation Ecosystem or their contributing partners may be promoted to "Community Use" or "Clinically Reviewed." Not all designs require FDA approval, however some may be submitted to the FDA for Emergency Use Authorization, and will be marked as such. In addition, some designs that have undergone validation may be supplemented with a Technical Data Package (TDP). Site admins or content reviewers may contact you if a TDP is in process.

What is needed for an N95 design proposal?

Respirator (N95 type) devices offer the highest level of protection to the user, and because of this, require the highest level of performance testing and evaluation of the three types of face masks. A proposal for supplemental respirator device requires a formal submission of an Emergency Use Authorization (EUA) to the FDA. More information about what is required can be found in these FAQs and in the Enforcement Policy for Face Masks and Respirators During the Coronavirus Disease (COVID-19) Public Health Emergency guidance from the FDA.

Some of the performance testing requirements for these face masks which are needed for the EUA submission include NIOSH Approval of Respiratory Protective Devices - 42 CFR 84 and OSHA Respirator fit testing - 29 CFR 1910.134 Appendix A.