IEC 60601-1-11 IP rating

[Julie]

Hi,


I’m currently certifying my product IEC 60601-1-11 and I’m wondering how to tackle 8.3.1 and the IP rating.

My product is Body-Worn, but it hasn’t been designed to have any water resistance. My product doesn’t have essential performance as it never comes into direct contact with the user.

If my product does come into contact with liquid or dust there is little risk to the user and I have information in the IFU regarding the water resistance.

If I do require IP rating, is this something that I can do myself? Rather than using a safety test house?

Thanks.

 

[BuckeyeBurro]

Hey Julie,

I have a couple of clarifying questions to ask:

• Does your device fit the definition of Medical Electrical Equipment (ME Equipment) according to IEC 60601-1? If not, though it may serve a clinical purpose and be a medical device, IEC 60601 may not be applicable. Instead, you may be looking at IEC 62368 or some similar standard. If IEC 60601-1 does not apply, you likely would not need to be certified to the collateral standards.
• Are you positive your device does not have essential performance? Essential performance does not necessitate direct contact; rather, it is a clinical function—the loss or degradation of which results in unacceptable risk. Nowadays (especially with the latest 3.2 edition of 60601-1), it is uncommon for a device not to have essential performance while also falling under the scope of 60601-1.
• If your device does not have essential performance, do you have basic safety? If so, section 8.3.1 still applies for basic safety.

If your device falls under the scope of 60601-1 and is designed for the home healthcare environment, or you just want certification to this particular collateral standard, then section 8.3.1 of 60601-1-11 would apply. In those cases, 8.3.1 is explicit that Body-Worn ME Equipment shall maintain basic safety and essential performance to at least IP22. If it is not body-worn or the other types listed, it shall maintain basic safety and essential performance to at least IP21.

Side note, if your device itself was not designed to be water resistant and you are too far along for a major design change, you can make a water-resistant/proof carrying case. The device will then just need to pass while in that case.

 

[BuckeyeBurro]

Hey Julie,

I have a couple of clarifying questions to ask:

• Does your device fit the definition of Medical Electrical Equipment (ME Equipment) according to IEC 60601-1? If not, though it may serve a clinical purpose and be a medical device, IEC 60601 may not be applicable. Instead, you may be looking at IEC 62368 or some similar standard. If IEC 60601-1 does not apply, you likely would not need to be certified to the collateral standards.
• Are you positive your device does not have essential performance? Essential performance does not necessitate direct contact; rather, it is a clinical function—the loss or degradation of which results in unacceptable risk. Nowadays (especially with the latest 3.2 edition of 60601-1), it is uncommon for a device not to have essential performance while also falling under the scope of 60601-1.
• If your device does not have essential performance, do you have basic safety? If so, section 8.3.1 still applies for basic safety.

If your device falls under the scope of 60601-1 and is designed for the home healthcare environment, or you just want certification to this particular collateral standard, then section 8.3.1 of 60601-1-11 would apply. In those cases, 8.3.1 is explicit that Body-Worn ME Equipment shall maintain basic safety and essential performance to at least IP22. If it is not body-worn or the other types listed, it shall maintain basic safety and essential performance to at least IP21.

Side note, if your device itself was not designed to be water resistant and you are too far along for a major design change, you can make a water-resistant/proof carrying case. The device will then just need to pass while in that case.

Sorry, I forgot to answer the last part of your question. While you can do such testing in-house to evaluate your design, you could not get a listing mark from an NRTL unless they perform the test themselves. I also would not suggest such testing as the burden of proof to demonstrate you have built a test system meeting the requirements of IEC 60529 is no easy task (unless you have the capital to purchase one).

 

[Peter Selvey]

The IP22 requirement in IEC 60601-1-11 is a bit of overreach and will probably be clarified in the future. Likely what the intention of the standard was to require that all devices undergo an IP22 test as an abnormal condition, in which generally essential performance is not required except in special cases (e.g. a high risk device that should continue to perform or shut down safety). And of course, any device that has exposure to liquids in normal condition should be designed and tested for those as a normal condition, and essential performance should remain (even for low risk devices). However, this aspect is already covered by 11.6 in the general standard.

It is not practical for many devices to work normally during or after in an IP22 test, which is a basic requirement of IEC 60529 (irrespective of any essential performance claim, see Clause 14.3, "water ... shall not ... interfere with normal operation ... "). For example, a common medical device used at home is a NIBP (non-invasive, cuff based, blood pressure). This kind of device could not reasonably perform during an IP test, or directly after the test (even with surface water removed), as the cuff would probably take days to dry effectively to the point where it doesn't affect sensitive pressure measurements.

However, if such a device has warnings against use with liquids, rain etc, using the umbrella mark (keep dry), then the IP22 test can be seen as an abnormal condition, for which it needs to be confirmed that the device does not catch on fire, cause shock or other basic safety issue.

Although the standard does refer to "essential performance", it is possible to define different levels of performance for different conditions. Under normal conditions, most devices should work normally. It is not reasonable to claim any device has no essential performance, although this is popular route. Rather, EP should be refined to cover different conditions, not a single blanket statement. Then, if the IP22 test is identified as an abnormal condition then it is plausible to claim "no essential performance" for that condition.

For a body worn device, there will potentially sweat and also rain. Therefore, the claim that IP22 is genuinely an "abnormal" condition would need to be carefully evaluated. If liquids are expected a waterproof design is reasonable and performance should be maintained under those conditions, even if low risk. It is nonsensical to have a medical device that cannot perform under reasonably expected normal conditions, regardless of the risk category. Note that the water exposure test condition could be refined to match the expected normal condition, if IP22 is considered excessive or not representative.