Flame Rating Class for Plastic Materials in Enclosure of Medical Equipment

[temujin]

Dear Forum,

I am in the process of building up the Technical File for the CE-Marking of a medical device.

Our Notified Body has required me to provide certificates/information on the Flame Rating (UL Rating) of all plastic material in the enclosure.

However, reading 60601-1, I cannot find any explicit requirements regarding Flame Rating for enclosures. My contact at the NB is also not sure where the requirement originates, he simply wants to have it.

Does anyone have experience with this requirement+


regards
t.

 

[Sunset - 2011]

Re: Flame Class for Enclosure of Medical Equipment

Hi temujin,
your enclosure is a critical safety component.

If I remember right, materials for medical devices must have a special flame rate class according to the standard ANSI/UL 94. I'm sorry, I actually forgot the mimimum requirement.

But you can go on the UL-website and search under certification for plastic material or plastic material companies or the UL code QMFZ2, if you click on one certificate, you'll find on top a link to general requirements for plastic components. May you find more information there.

The flame class also gives the maximum temperature for the material and maximum temperature requirements are under point 42 in the IEC 60601-1, I think. Please check.

I hope that helps a bit!

Anyone else if I'm wrong, please correct me.

Cheers,
Sunset

 

[temujin]

Re: Flame Class for Enclosure of Medical Equipment

Thanks Sunset,

As a European manufacturer we are not required to follow the ANSI/UL standard. Unfortunately I have only the 3rd edition of 60601-1. Does anyone know where to find "temperature requirements are under point 42 in the IEC 60601-1" in the 3rd edition?

regards
t.

 

[Sunset - 2011]

Re: Flame Class for Enclosure of Medical Equipment

HI temujin,

I'm sorry, I haven't got the third Edition, but if you follow through the standard, there will be a point with temperature requirements. There is a table which shows maximum requirements for components in medical devices.
Point 42 is of the 2nd Edition.

May someone else can help?
Thanks
Sunset

 

[Marcelo]

Re: Flame Class for Enclosure of Medical Equipment

There´s a new concept in the third edition called "fire enclosure", in clause 11.3. This is an alternative way to deal with the hazards described in 13.1.2 (emissions, deformation of enclosures or exceding maximum temperature). Keep in mind that just the flammabiulity classification (FV-1, FV-2) is not enough, you need to comply with all requirements of the clause, for example, the baffle construction if the equipment have openings as seen in figures 38 and 39. As you said that

My contact at the NB is also not sure where the requirement originates, he simply wants to have it

it seems that your NB does not know that (not a surprise, but still a stupid request as he seems to not know what he´s talking about).

 

[temujin]

Re: Flame Class for Enclosure of Medical Equipment

Thanks to all,

I am aware of the section on FIRE ENCLOSURE. However, what happen if the FIRE ENCLOSURE itself is covered by a second plastic ENCLOSURE? Would there be any specific requirements regarding the material of this secondary ENCLOSURE?

regards
t.

 

[Marcelo]

Re: Flame Class for Enclosure of Medical Equipment

If there were a second plastic ENCLOSURE, then the first ENCLOSURE would not fit the definition of ENCLOSURE anymore so it would not be a fire ENCLOSURE anymore! An ENCLOSURE is an external part. In this case, the plastic enclosure would have to comply with all requirements of the clause for fire ENCLOSURE.

 

[Steve McQuality]

Re: Flame Class for Enclosure of Medical Equipment

Hi Temujin:

Just got one of the Medical Industry Trade magazines today and there is an article in the most recent MD&DI that talks about plastic molding. I remembered reading your post this morning and thought I'd send this tid-bit along to you. Within the article, they talk about the UL Fire Rating. It might be worth a quick perusal and may help define the requirements as they stand alone. As far as their relationship to IEC 60601-1, I can't help you there...

Here's the link - http://www.devicelink.com/mddi/archive/08/07/006.html

Good luck,
-Steve
( I just realized this was my 100th Post - yea me!)

 

[jmalm]

Re: Flame Class for Enclosure of Medical Equipment

In terms of "enclosure", does anyone know if the flammability ratings extend for cables and applied parts as well?

Example, say I have an esophageal temperature probe and a cable that connects to a measurement device. Do the external surfaces of the probe and cable need to have 94V-2?

I know many applied parts carrying electrical signals use Pebax as the outer shell (eg some ablation catheters); Pebax is rated 94-HB so wouldn't seem to be covered by 60601's definition of "enclosure" for the purposes of applying flammability ratings (unless the Pebax they use has enhanced flame ratings).

 

[noorain]

Re: Flame Class for Enclosure of Medical Equipment

I'm aware that its to late to answer this, but assuming that other people might also be looking for the same answer, the auditor is looking for FV-2/ FV-1 flammability requirements.