×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

NFPA 70E arc flash hearing PPE

NFPA 70E arc flash hearing PPE

NFPA 70E arc flash hearing PPE

(OP)
The 2009 70E standard, while not available for delivery yet, is however, viewable at http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70e

I see that the requirement for hearing protection (Table 130.7(C)(10) has dropped two levels to risk category 0. In 2004 is was at 2, then went to three for the preprint proposal. This was never had an AR designation, so I assume the protection is for the sonic effect of a possible arc. Do you agree? Why is it the target moving around so much? And are not the insert style protectors melt-able and likely to contribute to injury?

Thanks.

RE: NFPA 70E arc flash hearing PPE

I have the 2009 70E sitting on my desk, got it about 3 weeks ago. I also noticed the hearing protection is in the FR PPE catagory, wonder if they need to be FR? Dont think so, because they would be covered by a head sock or flash suit hood but I am not sure on that. Cant find any guideance in the standard.  

RE: NFPA 70E arc flash hearing PPE

(OP)
Guess it the handbook I'm waiting on.

Most of the stuff listed under FR equipment is not arc-rated. I agree that the inserts would normally be covered by a face shield, sock, or hood. But risk category 0? Our worker has mad sure he is wearing no melt-able fabric, then sticks plastic foam in his ears?

RE: NFPA 70E arc flash hearing PPE

It's an interesting question.  I don't recall ever seeing any guidance on FR rating of ear canal inserts.

It's a work in progress - as always....   

RE: NFPA 70E arc flash hearing PPE

(OP)
I did a little more pouring over http://www.nfpa.org/assets/files/PDF/ROP/70E-A2008-ROP.pdf
Seems a proposer had an article showing category 0 arcs exceeding the OSHA impulse level of 140 dB. The committee rejected his proposal twice, but I guess it made the cut further into the process. No consideration to how hearing protection might contribute to injury could be found in the document.

There is at least one hearing protection product that is geared toward arc blasts. No mention of FR or arc ratings in any of it's literature.

To add to the confusion, it was suggested that the X under category 2 in the '07 70E was in error along with the reference to note 8.  

RE: NFPA 70E arc flash hearing PPE

(OP)
Update:

Seems e-hazard has done some testing. The yellow foam (don't use red) will not sustain a flame, and they won't fuse into the ear canal as I feared. A little bit of melting at the exposed end can occur, and they are still removable afterward. Doesn't neet NFPA, but it's all we got.

RE: NFPA 70E arc flash hearing PPE

Is the yellow foam the same across all brands or was a specific brand tested?

RE: NFPA 70E arc flash hearing PPE

If you are wearing all of the proper PPE the hearing protection wont be exposed to the arc flash. Thats why there is not a FR requirement for them.  

RE: NFPA 70E arc flash hearing PPE

(OP)
wbd,
I believe a sampling of brands was tested, with similar results.
Zog,
HRC 0 does not require any PPE over the plugs, such as as an FR face shield or balaclava. The table lists the hearing protection under "FR Protective Equipment."  

RE: NFPA 70E arc flash hearing PPE

And HRC 0 is for Ei's less than 1.2cal/cm2, the plugs wont melt. As far as the section they were placed in the tables, where else would they put them?

RE: NFPA 70E arc flash hearing PPE

(OP)
Zog,

At HRC 0 and higher, one is forbidden from wearing meltable articles. E-hazard's testing confirms that they do melt, although minimally.
 
I don't know where they should be put, but the presently available plugs cannot be considered to be FR. NFPA seems to have got in front of the manufacturers and ASTM by requiring a protective item that does not yet exist.

RE: NFPA 70E arc flash hearing PPE

"NFPA seems to have got in front of the manufacturers and ASTM by requiring a protective item that does not yet exist"

They exist, just not widely available. I will talk to the ehazzard owner on Monday and get more info on the testing.  

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources