For the uninitiated, electrical safety certification of medical devices is a dazzling cornucopia of intermeshed standards and marks. It takes some in depth studying to disentangle all the various aspects. But let’s give it a go!
NRTL’s, Standards, Marks, and Regulatory Agencies
What makes this topic especially confusing is that there are multiple aspects to consider, which all intersect and intermingle.
NRTL’s
NRTL is an acronym for “nationally recognized testing laboratory”. These are companies that have been authorized by the US government to certify products to the standards. Two of the biggest traditional laboratories are UL (Underwriters Laboratories) and CSA (Canadian Standards Association). CSA is a state-owned enterprise of the Canadian government. UL is a private organization in the United States that has been certifying product safety since 1894.
There are other testing labs that can also perform certification testing. The number of NTRL’s is increasing in recent years. All these various NRTL’s are in competition for your business. Some of the newer NRTL’s may be considerably less expensive than the better known NRTL’s.
The Standards
The standards you need to comply with depends on your market and applicable regulatory laws.
IEC establishes the most general standards which have the greatest applicability for a variety of global markets. Most medical products will be covered by at least one of two basic standards. IEC 60601-1 is the standard that defines basic safety and essential performance for medical devices. This standard typically applies to devices that have direct contact with the patient, with applied parts or energy delivery. For in vitro diagnostics, IEC 61010-1 for laboratory equipment is the standard that usually applies. There are other more specialized standards that may apply for particular applications.
The IEC 60601-1 standard is intended to align closely with ISO 14971 design control for medical devices. IEC standards also serve as the harmonized basis for many other organizations’ standards.
This is where it really gets confusing. Some NRTL’s also have their own standards that they’ve established.
CSA is not only an NRTL. It also defines its own standards. Products tested to the CSA standard can bear the CSA mark on their label. Medical devices sold in the Canadian market will need to comply with the CSA standard. But the CSA NRTL testing service can also certify to other standards, including IEC 60601-1.
UL has its own standards, including some derived from IEC standards. The UL mark is not mandatory in the US.
Within the EU, the CE mark is granted by a notified body. The EU requires compliance to the IEC standards for electrical safety. Well known notified bodies include BSI, TÜV, and Eurofins, but there are many other newer companies as well.
Medical device companies will typically choose one NRTL for their electrical safety testing, and have them test to a variety of standards depending on their intended market.
Marks
Once you’ve been certified to an NRTL’s standard, their mark can be applied to your product label to claim compliance to their standard.
These marks may involve a periodic audit by the NRTL to ensure continued compliance to the standard. If the product is revised, the NRTL may require you to perform testing again to keep your certification. The certification report will typically include a list of critical components included in your original testing. If one of these components needs to be changed, such as due to obsolescence, your product may fall out of compliance. The NRTL may revoke your certification and disallow application of their mark.
UL and CSA are commonly applied marks. Lesser known NRTL’s are growing in popularity, including Eurofins’ MET mark and Intertek’s ETL mark among others.
For the EU, a variety of companies are recognized as notified bodies, authorized to grant the CE mark. The CE mark is the general safety mark required under EU MDR for all medical devices, and may include electrical safety as one aspect of product safety.
If you don’t require a particular mark for your intended market, it may be preferable not to apply the NRTL’s mark to your label, in order to avoid the burden of perpetual compliance audits and retesting.
Regulatory Agency Requirements
The FDA requirements on electrical safety are somewhat vaguely defined. While the FDA does not explicitly require compliance to any particular standard, it does officially recognize some standards. Certification to these standards may be used as part of a regulatory submission to demonstrate safety.
With design changes that may impact electrical safety, it’s not always clear whether recertification to a standard is required. The FDA ultimately requires the manufacturer to demonstrate safety and efficacy of their product. It’s up to the manufacturer to manage risk and ensure continued compliance. The manufacturer is likewise responsible for notifying the FDA of significant design changes to their product. Like-for-like component replacements which don’t involve a change to form, fit, or function may be justifiable without a recertification. If the product doesn’t bear the mark of an NRTL, it’s up to the manufacturer to determine whether retesting to a standard is required.
The EU requires compliance to applicable IEC standards as part of the CE mark process. It is the responsibility of the manufacturer to assess risk, ensure continued compliance, and notify the certifying agency of significant design revisions.
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