how to use bubble bombs_Protective helmets requirements and selection

Introduction In many industrial working environments, for example, mining, power, construction, and forestry, the risk of head injury to workers is constantly present. The most serious risks are physical injuries, which can be as a result of the impact of a falling object or collision with fixed objects at the workplace. Due to the nature of these work activities, it is not always possible to eliminate such risks with just appropriate organisational solutions or collective protective equipment. Therefore, the only way to ensure the safety of workers is by using safety helmet s. The type of helmet will depend on the specific nature of the physical risks that have been identified in the risk assessment undertaken for the activity. This article provides information for users of protective helmets as well as employers and OSH engineers. It includes information on definitions and gives the requirements for different kind of protective helmets that offer protection against physical risks. Basic information Personal protective equipment (PPE) means all equipment which is intended to be worn or held by people at work and which protects them against one or more risks to their health and safety, and any addition or accessory designed to meet that objective. All PPE should be used as a last resort to reduce the risk taking into consideration that the risk will not be eliminated. Safety helmets are one of the most frequently used forms of PPE. Safety helmets will protect the user’s head against: impact from objects falling from above, by resisting and deflecting blows to the head. hitting fixed dangerous objects at the workplace, lateral forces - depending on the type of hard hat selected. Traditional hard hats are not designed to protect users from impacts to the front, side or back of the head. open flame, molten metals splash, electric shock, high temperature – depending on the additional protective properties of the hard hat selected, e.g. a basic, standard safety helmet does not protect against an electric shock. In general, protective helmets, or hard hats, should: Resist penetration by objects, Absorb the shock of a blow, Be water resistant and slow burning, and Come with instructions explaining proper adjustment and replacement of the suspension and headband. All employees working in areas where there is a possible danger of head injury from impact, or from falling or flying objects, or from electrical shock and burns, shall be protected by protective helmets. Safety helmets must be worn when performing most construction works, works in the vicinity of lifting equipment (cranes, hoists, etc.) and suspended loads, works in forestry, works in cisterns, wells, shafts, tunnels, etc. In these situations the use of a safety helmet will help protect against injuries to the scalp, skull and cervical vertebrae. It is the responsibility of the employer to conduct a risk assessment and determine the need for head protection at the workplace. In some situations the safety helmets serves as a base for other kinds of PPE i.e .will be used together with other PPE, e.g. hearing protection, face visors or respiratory protection equipment. In these situations it is important that the suitability and the compatibility of the different PPE are considered. Figure 1 shows the construction and the individual components of an industrial safety helmet. All safety helmets should come with instructions on how to correctly adjust and adapt the helmet for each individual user’s needs. It is therefore important that before using the safety helmet, the user should read and become familiar with these safety instructions. When adjusting and positioning a safety helmet on the head, the user must ensure that the: harness straps crossing the top of the helmet adhere closely to the head, headband which runs around the head strictly adhere to the forehead and nape of the neck, safety helmet is securely mounted on the head i.e. the helmet must be positioned on the head and should be limited by the minimum amount of clearance between the hard shell and the skull. This will give a low center of gravity and provide exceptional balance. helmet should be adjusted in a manner that even without the use of a chin strap it will stay on the head without falling. Labelling of helmets and safety requirements EU legislation distinguishes between two areas of regulations regarding personal protective equipment. The first is discussed in Directive 89/656/EEC [1] , which determines the obligations of the employer regarding ensuring safe use of personal protective equipment. The provisions of this Directive also include employers’ obligations connected with the necessity to use personal protective equipment. Safety helmets should be appropriately selected by the employer, based on a risk analysis, and delivered to the employees free of charge. The employer is also responsible for the maintenance of safety helmets and their replacement, in particular if the used items have reduced protective properties. The second area of regulations with regards to personal protective equipment is connected with Regulation 2016/425/EU [2] . It concerns the rules of placing the products on the common market, i.e. the assessment of conformity with essential health, safety and ergonomics requirements (EHSRs). Therefore, hard hats, should meet the requirements of the Regulation referred to above. It follows from these requirements that the manufacturer of hard hats — or their authorised representative — is responsible for the conformity of the products placed on the EU market with the essential requirements specified in the Regulation, which is confirmed by placing a CE mark on the product. The minimum information that should be included with the helmets is: European standard number name or a logo of the manufacturer production year and quarter type of helmet size. A helmet which offers additional protective features may also have a label on the shell with information regarding: electric insulation properties, resistance to lateral forces, resistance to molten metal splashes, resistance to very high temperatures, resistance to very low temperatures. Operating manual / Safety Instructions Under Regulation 2016/425/EU the manufacturer is required to provide safety information regarding the hard hat in their technical file. All safety helmets should come with an operating manual / safety instructions which should cover all relevant information such as: safety features, adjustment methods, how to fit it properly onto the user’s head, maintenance, storage and repairs / replacement. These instructions should be clear and comprehensible. Types of helmets Industrial safety helmets According to EN 397 [3] , the most common and basic form of PPE aimed at protecting an employee’s head is an industrial safety helmet. Regardless of the differences in their structural protection, these type of helmets will feature the following components: shell, harness and headband. Figure 1: Construction of an industrial safety helmet. 1 – shell, 2 – harness, 3 – harness fixing, 4 – headband, 5 – sweatband, 6 – peak, 7 – chinstrap. Source: CIOP-PIB The helmet’s shell is the rigid outer section of the helmet, and is usually made from polyethylene, ABS (Acrylonitrile Butadiene Styrene – a thermoplastic) or fibreglass hardened with polyester resins The basic function of the shell is to provide protection by reducing the force of a falling object striking or impacting on the users head. Depending on its design, the shell can have a peak, a brim or a rain gutter, ventilation openings, or attachment devices for eye and face protection and ear protectors. The harness is the internal part of the helmet (fastened to the inside of the shell) consisting of a system of strips made of woven bands or polyethylene. The main purpose of the harness is to absorb the energy from an impact on the shell and to spread the force evenly over the wearer’s head, minimising the risk of harm to the user. It should be noted that a helmet, with the harness closely attached to the rim of the shell and without any additional protective padding, will not provide effective protection against any lateral impacts [4] , [5] , [6] , [7] . However, helmets with shells of sufficient rigidity [3] will also provide partial protection of the user’s head against any lateral forces. The shell and harness have been designed to work together in the helmet as a unit when fitted the correct way round i.e. the peak facing forward. The harness should not be removed and refitted so that the helmet can be worn backwards because the helmet has not been designed to absorb impact when worn in this way. The headband is the part that contours the head at the height of the forehead and the base of the skull and, together with the harness, allows for the stable positioning of the helmet on the user’s head. The headband is equipped with two adjustment mechanisms for changing its length and the wearing height, and this increases its stability when positioned on the head. Most industrial protective helmets will have a sweatband incorporated in the headband which acts as a sweat-absorbing pad. Industrial safety helmets can also have additional equipment which does not need to be included, such as a chinstrap that is designed to keep the helmet in place and prevents it from falling when workers move their heads or they might include grips for attaching other personal protective equipment elements, e.g. eye and face protection. Industrial bump caps Industrial bump caps (standard EN 812) [8] should only be used in workplaces where the risk assessment has identified no hazards from objects falling from above and only a danger of superficial head injuries caused by light impact against structural elements. In these cases an industrial safety helmet [3] would not be required. By wearing an industrial bump cap, workers can avoid the following discomforts: the pressure being exerted by the harness and the headband on the users head. the additional weight on the neck muscles from the helmet mass bump caps are lighter than industrial safety helmets. the lack of ventilation on the upper part of the head. This is especially bothersome whilst doing hard physical work and or when working at high temperatures in the workplace. The most important elements of an industrial bump cap in comparison with designs that comply with the specifications in EN 397 [3] is their lower mass and their smaller dimensions. Figure 2 shows an example of an industrial bump cap. Figure 2: Construction of an industrial bump caps. 1 - internal shell, 2 - nape band, 3 - protective padding Source: CIOP-PIB Bump caps consists of a thin polyethylene shell, a harness and a headband which is made of plastic by an injection method. Bump caps can also be made of textile materials (making them approximately 50% lighter than helmets complying with EN 397) and equipped with a special protective padding. High performance industrial safety helmets There are industrial workplaces where the risks of head injuries are so high that industrial safety helmets compliant with the EN 397 [3] are not sufficient to provide a suitable degree of protection. Examples of industry sectors where such workplaces exist include mining and construction. In such cases, the risk assessment undertaken would have identified that employees must be equipped with high performance industrial safety helmets i.e. helmets that comply with EN 14052 [9] . Compared to the helmets compliant with the EN 397 [3] , these helmets are characterized by the following properties: they provide the same level of shock absorption (i.e. force transmitted to the user’s head) when exposed to an impact with a double energy (the impact energy during the testing of high performance industrial safety helmets (EN 14052) is approximately twice the amount used for industrial helmets (EN397)). they protect the head against vertical impacts (on the highest point on the shell) and against lateral impacts (from the front, back and sides). they ensure an increased level of protection against the impact of sharp objects. High performance industrial safety helmets also consist of a shell, harness and a headband. The most popular method of enhancing the helmets shock absorption properties and provide protection against lateral impact, is by the introduction of protective padding that absorbs the energy from the impact and therefore reduces the forces transmitted onto the user’s head. This padding is usually made of foams with adequate force-deformation ratio properties, e.g. polyurethane or high-density polystyrene. An example of such a design is shown in figure 3. Figure 3: Construction of a high performance industrial safety helmet. 1 – shell, 2 – harness, 3 – headband, 4 – sweatband, 5 – chinstrap, 6 – protective padding Source: CIOP-PIB The design of these types of helmets includes a more stable method of fitting onto the user’s head in order to prevent it from falling during an impact, especially lateral ones. This additional stability is reflected in the construction of the headband, the chinstrap and the system of supporting the helmet. Better resistance to penetration is achieved by using shells made of thicker or harder materials. However, achieving this additional protection results in an increase in mass of the helmet and therefore an additional load on the user. Requirements and selection To provide the users head with a suitable level of protection against physical factors, the helmet must be properly selected, fitted and used. Selecting a helmet to suite the user and situation The term “selected" refers to the employer undertaking a comprehensive risk assessment to establish the need for head protection within the area and to determine its suitability. It is important to note that all PPE should be used as a last resort and only after implementing other controls. With regard head protection the employer will have a choice of three different types of head protection i.e. industrial bump caps, industrial safety and high performance industrial safety helmets. According to the above-mentioned standards EN 397, and EN 14052 safety helmets must comply with a series of requirements, which relate to the following issues: materials used for the production of shells and interior equipment geometric structural parameters shock absorption resistance to penetration resistance to flame. Special purpose helmets have to comply with additional requirements regarding: breaking strength of the attachment points of the chinstrap dielectric properties resistance to lateral forces resistance to molten metal splash resistance to high temperatures. In order to provide proper protection of the user’s head against mechanical impact, safety helmets must be suitably selected from different types and constructions. When making a decision on the selection of a particular helmet, the employer must choose taking into consideration the following factors: The characteristics of the risk factors identified in the risk assessment and for which protection is needed (e.g. vertical impact, lateral impacts, transverse compression forces, etc.) Operating temperature range. The helmet shall maintain its safety parameters in the entire range of temperatures occurring at a workplace. There are four categories of helmets classified according to this feature: basic (operating temperature range from -10°C to +50°C - no special marking of the helmet) for low temperature applications (operating temperature range from -20°C - labelling on the helmet -20°C) for very low temperature applications (operating temperature range from -30°C – labelling on the helmet -30°C) for very high temperature applications (operating temperature range to +150°C – labelling on the helmet +150°C) Must suit the user – consider the size, fit and weight of the helmet. Adjustment range of the main ring and the wearing height of the helmet must be appropriate for user’s head size. If the users help to choose their head protection, they will be more likely to use it. Adjustment means conducting proper fitting, i.e. adjusting the perimeter of the main ring, the height of wearing, and the length of the chinstrap in order to adapt the helmet to the size of the user’s head. Presence of other hazards (e.g. electric shock, high temperature): at workplaces where there is an electric shock hazard, helmets with dielectric strength shall be used – labelling on the helmet: 440V AC. at workplaces where worker is exposed to the impact of melted metal fragments, helmets resistant to such impact shall be used – labelling on the helmet: MM. at workplaces where there is a risk of lateral deformation of the head, helmets resistant to this type of hazard shall be used – labelling on the helmet LD. at workplaces where intense physical effort is required at high ambient temperature, causing excessive sweating, a helmet with good ventilation should be chosen, e.g. equipped with ventilation openings and a sweat absorber. at workplaces threatened with explosion hazard, helmets with anti-electrostatic properties shall be used. Performing tasks that can cause the helmet to fall down from the head (e.g. using it together with personal protective equipment for the protection of falls from a height If the tasks performed at a workplace may cause the helmet to fall down from the worker’s head, for example due to the position that he must adopt during work, then a helmet should be selected with a construction that will prevents this, i.e. with a specially formed headband to precisely fit the back of one’s head or with a chinstrap. A requirement to use other elements of personal protective equipment and additional accessories (e.g. eye and face protection, ear protectors, a lamp installed above the peak, etc.) together with the helmet. It is important to make sure that if more than one item of PPE is being worn that they can be used together. Proper use of the Safety helmets Proper use means following the rules and instructions specified by the manufacturer in the operating manual e.g. conditions and ways of using the product, recommended methods of maintenance and storage as well as the conditions for qualifying a helmet for withdrawal from service. The most important rules of proper use of safety helmets include: Prior to using, a helmet must be fitted to the user’s head by proper adjustment: of the headband, height of wearing and the length of the chinstrap (if it is present). Helmet must be withdrawn from service if it was exposed to a strong impact or shows signs of damage. Interior elements of a safety helmet must be regularly inspected (harness, headband, sweatband) as they are exposed to sweat, dust, etc. These factors cause an accelerated degradation of the materials of which the helmet components are made. Parts inside the helmet shall be replaced as often as required by the manufacturer and every time any damage is detected during inspection. In the case of doubts, interior elements shall be replaced or the entire helmet substituted by a new one. Helmet should be withdrawn from service if its expiry date, specified by the manufacturer in the operating manual, has passed. Helmet shall be stored in compliance with the conditions specified by the manufacturer, which pose no threat of losing its safety parameters (far from heat sources, direct solar radiation, etc.). The construction of the helmet must not be modified by users, no stickers shall be attached to the shell nor shall it be painted, etc. The maintenance of the helmet shall be conducted using methods recommended by the manufacturer. Usually helmets can be cleaned with mild detergents and warm water (not hotter than 45°C). Conclusions Statistical data regarding occupational accidents show that the most common cause of head injuries are impacts from falling objects and impact against sharp and hard items. The consequences of such an occurrence depend principally on the kinetic energy of the impact and the shape and hardness of the material coming into contact with the head. Injuries caused by mechanical factors may affect skin on the head, skull, brain and neck segments of the spinal cord. In extreme cases, these injuries may lead to permanent disability or even a person’s death. All the tasks related to the selection, maintenance, training in safe use, conducting inspections and running a register of safety helmets is the responsibility of the employer. When it follows from a risk assessment the user must wear a safety helmet from the very beginning of his work and for the entire duration of the shift and is responsible for using head protection equipment in accordance with its purpose. He shall also notify the employer or a suitable occupational health and safety representative of any defects of this equipment. However, one must remember that the use of helmets does not eliminate dangerous factors but only reduces the gravity of their consequences. References [1] Directive 89/656/EEC - use of personal protective equipment of 30 November 1989 on the minimum health and safety requirements for the use by workers of personal protective equipment at the workplace. Available at: [1 ] [2] Regulation (EU) 2016/425 on personal protective equipment of the European Parliament and of the Council of 9 March 2016 on personal protective equipment and repealing Council Directive 89/686/EEC (with effect from 21 April 2018). Available at: [3 ] [3] EN 397 Industrial safety helmets. European Committee for Standardization. Available at: https://www.goodsafetyhelmet.com/ [4] Korycki, R., ‘The Damping of Off-Central Impact for Selected Industrial Safety Helmets Used in Poland’, JOSE, volume 8, number 1, 2002, p. 51-70. Available at: https://www.goodsafetyhelmet.com/products [5] Baszczyński, K., ‘Industrial safety helmets – protection of the head against side impact’, Occupational Safety, CIOP - PIB, Warsaw, May 2002, number 5, page. 10-13.