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ekstra   ara
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PostPosted: Sat Apr 11, 2009 7:41 am 
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Upon reading this passage several times and listening to the input from other forum members, I would also agree that the interpretation is implying that that balaclava would be necessary from 1.2 to 8.0 cals. If we are correct in this interpretation, then the real question arises - Who is proof reading the handbook? What this has done is to create a severe conflict between the code and the interpretation. The handbook interpretation, and the HRC1&2 item list, can NOT both be correct simultaneously. We are all taught that the Code overrules the interpretation, so HRC1&2 code does not include the balaclava The only assumption possible is that protection is provided by the face shield, and that the back of the neck is effectively protected because of the deflection of the blast around the shield. For the author to add an interpretation that under 8 cals the balaclava required is in clear conflict. IF the author felt that the balaclava was a requirement, then he should have insisted that it be included in the Table for HRC 1&2. I really have to question the 'quality control' of the NFPA product. It is amazing to me that this was not caught and corrected before release. NFPA missed this, and they also missed that IEEE meant 208V and below was to be exempt from analysis and not the 240V and below NFPA published.

To avoid the hailstorm of comment, I am not debating whether or not the balaclava is needed below 8 cals. All I am stating is that the 'handbook' is supposed to interpret and examplify the 'code' so that it can be better understood. Since the Table does not include a balaclava for HRC 1&2, the author never should have made this claim, and the NFPA editor should have caught it.

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PostPosted: Tue Jun 02, 2009 4:36 pm 

Joined: Tue Jun 02, 2009 1:40 pm
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haze10 wrote:
Are you then saying that the balaclava is required for all IE > than 1.2 cal/cm2. If so, why is the handbook referencing 7.9 cal/cm2.

If the 'front' is 1.2 cals exactly, then anything further away from the 'front' like the 'back' of your neck is less than 1.2 cals and doesn't need protection.

So is the handbook saying that when the working distance (the 'front' of the chest and face) is 7.9 cal/cm2 only at that level and higher you need the balaclava? You seem to be saying at anytime the back of the neck is greater than 1.2 cal/cm2. But all calcs are done to the 'front'. So is it that at 7.9 in the 'front' you have 1.2 (based upon average neck thickness) in the 'back' (and greater of course).

Sorry, but I just find this very confusing.

To add to the confusion, what about the case where the IE at the hand is say a 5 and your head is out of the boundry but the fireball travels up your arm goes under your face shield and hard hat and burns all the hair off your head including eye lashes. What IE is required to burn the hair off the back of your neck. As for hood versus sock, when we reach the hood stage we are wearing the sock inside it. Our hoods do not seal to the jacket of the 40 cal suit (hood, jacket, overalls) so the possibliltiy exists that flame could get under the hood.

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