7.7 Head, Face and Eyes Protection
At present, there is no IEC standard for arc protection for the head, face and eyes and IEC 61482-2 is only for garments. There is, however, a standard being written with the probable title of “Live Working – Eye, Face and Head Protectors against the Effects of Electrical Arc – Performance Requirements and Test Methods”.
In the meantime, there are a choice of products available that may give the protection that you need. The advice is that you must use a face shield with a reputable arc rating. Where fabric forms part of a head assembly as shown in the following image Figure 7.9, then the fabric can be tested to either the box test or the open arc test and given either an arc protection class (APC) or an arc rating. There are also many products on the market that are tested to ASTM standards (American Society for Testing and Materials) such as the ASTM F2178 / F2178M - 20 Standard Specification for Arc Rated Eye or Face Protective Products. If it tested to that ASTM standard, then an ATPV is available but not an ELIM. There are German standards available that require testing to box test to BG-Prüfzert GS-ET-29:2010- 02: Supplementary requirements for the testing and certification of face shields for electrical works and suppliers will often quote both an ATPV as well as a box test APC 1 or 2. A face shield which is tested to American standards will be valid as they are similar to the IEC open arc test.
The face shields are often made from energy absorbing formulations that can provide higher levels of protection from the radiant energy. The shields are tinted so advice should be sought from the manufacturer in respect of light transmission class, as they may compromise colour perception visual acuity. This is obviously an important issue and supplementary illumination of the work area might be necessary when these types of arc protective face shields are used.
There may be a requirement for the protectors to cover not only eyes and face, but also further the entire head, including the neck. This needs to be addressed in the risk assessment. If necessary, this can be provided by a hood to cover all the areas simultaneously.
The images below (Figure 7.9) show typical face shields mounted with a fabric chin and neck guard on a helmet or a brow guard and often come with an open arc test ATPV of around 12 cal/cm2 and typically box test APC2.
Figure 7.9 Images courtesy of J K Ross
These examples can be supplemented by an FR balaclava to give 360-degree protection.
7.8 Hand Protection
Hand protection comprising rubber insulating gloves and leather over protectors have been worn for electric shock protection for many years. The good news is that the same combination provides fairly good protection against arc flash as well. There are, however, arc flash protection gloves that have been tested to both box and open arc test methods and they are readily available in Europe. Furthermore, products are available with high level of cut resistance and chemical protection. Care must be exercised if choosing leather over protectors to ensure that they are unlined or lined with non-flammable, non-melting fabrics. Heavy-duty leather gloves with minimum thickness of 0.7mm meeting this requirement have been shown to have ATPV values in excess of 10 cal/cm2. (Source - NFPA 70E:2015 Standard for Electrical Safety in the Workplace) The specialist arc flash protection gloves are available with an ATPV of > 50 cal/cm2 and/or ARC 1 or 2 classification.
The standard for insulating gloves is IEC 60903 Electrical Insulating Gloves. There are insulating gloves on the market in Europe that claim that over protectors are not required although care is always required that the dielectric properties are not compromised through heavy use. From personal experience, leather or specialist over protectors do not reduce dexterity if sized properly and paradoxically can sometimes improve the grip of small components. To determine the size, measure the distance around the palm of the hand, just behind the knuckles and choose the next available size up.
7.9 Foot Protection
I am not aware of any standards but normal industrial heavy-duty leather footwear provides a degree of arc flash protection. You may think that the feet will be the body part furthest away from an arc flash incident and usually you would be right. There are situations however, when they are the closest to a possible arc such as phasing out a pavement mounted link box for an electrical utility for instance.
Although hearing protection for arc flash protection is much debated, there are no specific standards requiring arc rated hearing protection. Future standards may deal with the need for testing FR ratings if part of an overall head and face protector.
The general consensus of opinion appears to be that standard canal inserts to reduce sound pressure exposure above 100 dB will be adequate. In this way the inserts (and the person’s ears) will be protected by a shield, hood or balaclava. Canal inserts typically give a SNR (Single Number Rating) of 30 and most large suppliers have SNR 33 canal inserts which will give the desired protection. Canal caps are not favoured they tend to be held in place with plastic that can melt and tend to be less efficient.
7.11 Pragmatic Approaches to PPE Selection
At this stage, if you have followed the 4P approach, any PPE that is prescribed will be as a last resort and for the residual risk only. Where an ATPV is used, it is likely that the majority of calculated incident energy levels at control panels and switchgear will now be below 1.2 cal/cm2, or the threshold of a second-degree burn. Furthermore, the vast majority of incident energy levels in industrial and commercial environments will be in single figures. The remainder may be quite high in magnitude. This fact will allow the duty holder to think about protection in terms of categories based upon the risk assessments on a local basis. So, if the majority of levels are below 8 cal/cm2 for instance, then a simple approach will be to have a standardised level of 8 cal/cm2. At this level, there are many options available giving a very comfortable single layer solution. This has been called “basic protection” and every situation above this level as “enhanced protection”. (reference Jim Phillips – Arc Flash Hazard Calculation Studies) For those enhanced protection situations there may be a simple solution involving layering which is covered in my earlier section on layering.
- PPE can only be prescribed in Europe after the employer has analysed and assessed the risks which cannot be avoided by other means.
- Follow the assessment of PPE which shall involve an analysis and assessment of risks which cannot be avoided by other means.
- Involve the users at an early stage to get acceptability and compliance.
- Try to follow a simplified pragmatic approach to PPE Selection.