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Head Protection Equipment [Jan 2005]

Need an item of protective headwear?

Easy! Just visit the local DIY, industrial supplies or sports shop and pick it off the shelf. Well no, it’s not as simple as that.

Every year many workers are killed or seriously injured in the construction industry as a result of head injuries. Wearing an appropriate safety helmet significantly reduces the risk of injury or even death. Protective headwear could save your life.

Protective headwear has developed significantly in the last twenty years and the range and scope of headwear solutions available for individual tasks is vast. That means it can be confusing for Health and Safety professionals trying to ensure adequate protection is afforded to employees. This confusion is magnified further when considering consumer markets.

The variety and diversity of the activities undertaken by individuals in both business and leisure necessitates the need for numerous different types of head protection. Headwear applications range from simple industrial bump caps to modern sophisticated integrated, head, eye, respiratory protection and communications equipment used by the emergency services.

Personal Protective Equipment (PPE) is defined as ‘any device to be worn or held by an individual for protection against one or more health and safety hazards’. The Regulations also apply to any system placed on the market in conjunction with PPE for its connection to another external, additional device.

Protective headwear is expected to be safe and fit for its stated purpose. Before purchasing any PPE specifiers should consult the ‘Personal Protective Equipment at Work Regulations 1992’. The Regulations contain 14 regulations for employers to consider as part of their pre-purchase risk assessment. Purchasing to a standard does not necessarily satisfy all of the requirements of Regulation 6 – Assessment of PPE.

What does protective headwear do?

The head is vulnerable to many dangers and protective headwear is designed to reduce the risk of injury to the wearer and, if supplied as PPE, to reduce the risk of litigation against the employer.

Headwear, depending on the application, should be selected to protect the wearer from an identified risk. Not all headwear offers the same levels of protection, for instance an industrial hard hat does not offer the same level of protection as an equestrian helmet. Headwear is intended to:

• Protect against direct impacts
• Prevent electric shock
• Reduce contre coup (whiplash neck) injury
• Withstand flame
• Protect against penetration
• Protect against radiant heat
• Reduce rotational element of injury
• Protect against crash

What are you protecting?

The human head is made up of distinct levels of complexity.

• Scalp - The outer covering of skin, muscles and blood vessels
• Galea - A thick covering between the bone and muscles of the scalp
• Bone (skull) - Frontal and Occipital are thick. Parietal on the side is thin
• Dura matter - Thick fibrous adherent membrane covering between the brain and bone
• Brain - Including arachnoid matter with blood vessels

Protecting the brain

In essence the brain is extremely well protected by the biological make up of the human head. The Frontal lobe and the Occipital lobe are protected by bone. Many small and thin bones surround the Medulla at the base. However the Cerebrum on the side of the head has poor protection.

Head injuries

The severity of injury sustained is dependent on the nature and energy of impact and, when worn, the appropriateness of the headwear. Even when there are no visible cuts and abrasions the internal trauma suffered to the brain can be significant resulting in concussion, internal haemorrhage and brain swelling. Where impact penetrates the skull there is a high risk of Meningitis and brain abscess or even posttraumatic epilepsy.

Rotation and acceleration/deceleration injury are more damaging to the brain than direct impact against the fixed, immobile head. This is because rotation causes the layers of brain tissue to glide over each other like a pack of cards, causing shearing of the delicate connections between the nerve fibres. This can also cause small blood vessels deep within the brain to rupture. This type of injury requires expert neuropthological diagnosis and cannot be repaired through surgical procedures.

Minor jarring of the brain causes concussion, a clinical state of transient loss of consciousness due to temporary nerve cell dysfunction. In many instances retrograde amnesia can occur. Bruising on the surface of the brain is called cerebral contusion. There are two distinct variants of this:

• Coup contusions: a blow to the head when it is free to move accelerates the head and causes cerebral contusion at the point of impact. Scalp injury (bruise, abrasion or laceration) is likely to occur at the point of primary impact. Contusion or laceration of the brain surface often occurs at the site of a fracture, especially if it is depressed
• Contre-coup contusions: when the falling head strikes the ground it decelerates abruptly while the semi-fluid brain continues moving towards the point of impact. This causes more severe contusions in the area diametrically opposite the point of impact

Brain damage

Brain damage can occur through a variety of ways:

• A direct impact to the head that causes bleeding
• A penetration injury to the head that goes through the scalp and the skull causing localised damage. Depending on the nature of the object that penetrates this can also be the cause of serious infection
• Rotation. This occurs when the brain moves inside the skull cavity resulting in damage to small blood and nutrient vessels

Skull fractures

When the skull experiences a localised impact it may be deformed and may cause internal damage even when the skull does not fracture. A severe impact will result in a fracture. Medical research indicates that uncomplicated skull fractures are rarely fatal and it is the associated internal damage that is potentially lethal. Skull fractures may occur with no associated neurological damage and, conversely, fatal injury to membranes, blood vessels and the brain may occur without fracture of the skull.

A fracture of the skull is dependant on many variables including the thickness of the hair, scalp and skull, which part of the skull is struck or the direction of impact. It does not take great force for a skull fracture to occur.

Skull fracture can result not only from severe impacts to the head but also from merely walking into a fixed obstruction (73 Newtons or 5 foot pounds), from the 4.5 kg adult head falling from a height of 1 metre onto a hard surface (510 N), the head falling from a standing position (873 N), running into an obstruction (1020 N) or a 100g golf ball or stone thrown with moderate force against the temple.

Statistics

Headway, The Brain Injury Association, report that in the UK an estimated 1 million people in Britain attend hospital each year as a result of a head injury. Of the total injuries minor head injuries, resulting in unconsciousness for 15 minutes or less, account for 150,000 people. In addition 10,000 people will suffer moderate head injury, which can cause unconsciousness for up to six hours. Physical or psychological problems can still persist up to five years following the incident. Statistically 11,600 people will suffer severe head injury and remain unconscious for six hours or longer and after five years, only 15% will have returned to work.

In general, males are two to three times more likely to have a head injury than females. The age group most at risk of head injury is 15 to 29. In this age group, males are five times more likely to sustain injuries. The death rate following traumatic brain injury is approximately 9 per 1000. Therefore, this leaves a large proportion of young survivors who have more or less unimpaired life expectancy. By the year 2000 it is estimated that 135,000 people in the UK will require round the clock care after surviving severe head injury.

Road traffic accidents account for between 40% and 50% of all injuries; they are also often the cause of the most severe injuries. Domestic and industrial accidents cause between 20% and 30% of all head injuries; sports and recreation - 10% to 15%; assaults - 10%. Of particular concern is that 20% of all head injuries in children are caused by cycling injuries. Cyclists who wear helmets are 85% less at risk of head injury.

Statistics published by the Health and Safety executive illustrate the number of injuries sustained through work activities specific to being struck by moving objects, including flying or falling objects [see Table 1]. What is not clear from the statistics is the precise number of injuries and fatalities in total for head trauma through the wearing or omission of protective headwear.

Table 1: Injuries to workers struck by moving, flying/falling objects#

*Provisional figures
# Includes employed and self-employed

Legislation

As well as the product performance standards for head protection products there is also a raft of legislation to which employers and specifiers must comply. In the UK employers are subjected to four main aspects of law:

• Health and Safety at Work, etc Act 1974
  This Act states that employers or the self-employed are responsible for ensuring, so far as is reasonably practicable, the safety of their employees and others. This responsibility is reinforced by regulations
• Personal Protective Equipment at Work Regulations 1992
  The Regulations contain 14 regulations for employers to consider as part of their pre-purchase risk assessment. Purchasing to a standard does not necessarily satisfy all of the requirements of Regulation 6 – Assessment of PPE. The requirement is that PPE supplied is suitable in relation to the risk. PPE should be provided free of charge by employers
• The Construction (Head Protection) Regulations 1989 The regulations state that every employer shall ensure so far as is reasonably practicable that each of his employees who is at work on operations or works to which these Regulations apply wears suitable head protection, unless there is no foreseeable risk of injury to his head other than by his falling
• The use of protective headwear under certain circumstances is also referred to in other legislation including:
  • The Control of Lead at Work Regulations, 1980
  • The Ionising Radiation Regulations, 1985
  • The Control of Asbestos at Work Regulations, 1987
  • The Noise at Work Regulations, 1989

• Personal Protective Equipment Directive (86/686/EEC)

  For PPE products to be sold within the European Economic Area (EEA) they must be CE marked. The Personal Protective Equipment Regulations 2002 (SI 1996/3039) contain the enforcement powers extended to Trading Standards Departments.

  Failure to comply with these Regulations may mean that PPE may be prohibited from being placed on the EEA market. It should also be noted that if the product is placed on the market in non-compliance, the chance to CE mark the product may be forfeited.

  There are a few exemptions within the PPE Directive relating to equipment specifically for the Armed Forces, Police, PPE for self-defence (aerosol canisters, etc) and helmets and visors for two or three wheeled vehicle users. The PPE Directive breaks the certification of personal protective products into three categories:

• PPE of simple design, defined as ’products where the designer assumes that the user can himself assess the level of protection provided against the minimal risks concerned the affects of which, when they are gradual, can be safely identified by the user in good time’ – for example gardening gloves, thimbles, etc
• PPE of complex design, defined as products the design of which is ‘intended to protect against mortal danger or against dangers that may seriously and irreversibly harm the health, the immediate effects of which the designer assumes the user cannot identify in sufficient time’ – for example respiratory protective devices, chemical suits, and fall arrest equipment
• PPE of intermediate design, product that is of neither simple nor complex design – for example most forms of eye protection

The CE mark is a product conformity mark; it is neither a product quality mark nor a mark of origin and should not be interpreted as such.

Voluntary certification

Manufacturers can underline the quality of their product through voluntary third party certification marks such as BSI’s certification trademark, The Kitemark. Voluntary certification requires products to be subjected to continual testing and quality systems auditing. In the case of Kitemark, this can be achieved for a wide range of personal protective equipment including most headwear applications.

What are the differences between CE marking and Kitemark?

The CE mark and Kitemark are not identical; one does not supersede the other. The Kitemark complements the CE mark. While the CE mark is the minimum legal requirement for Europe, the Kitemark offers an additional programme of continual compliance monitoring of product and quality systems and thus gives peace of mind.

Product specifications

Covering the complete scope of headwear applications there is a range of applicable product standards and specifications available [see Table 2]. Each standard is pertinent to a particular type of headwear and the product performance criteria differ extensively in line with the risk associated with the related activity.

Table 2: Headwear related specifications

The direct comparison of specifications is always difficult and subjective. To demonstrate the diversity of test performance criteria Table 3 outlines the impact levels for selected specifications.

1. Maximum permitted deceleration/transmitted force:
   1. For tests during which headform is dropped deceleration on impact is measured in units of deceleration due to gravity
   2. For tests during which a striker is dropped onto the test sample transmitted force is measured in kilo Newtons
2. The mass of each test headform is dependent upon its size, drop heights vary cross the size range of test samples to give nominally the same impact energy irrespective of helmet size
3. The mass of each test headform is dependent upon its size. Drop heights are constant across the size range of test samples giving the lowest impact energy for the smallest size helmet and the highest impact energy for the largest size helmet

Selection of head protection

When evaluating the suitability of head protection for a specific application consideration must be given to the definition of suitability in relation to the Regulations:

• It is appropriate for the risk or risks involved and the conditions at the place where exposure to the risk may occur
• It takes account of ergonomic requirements and the state of health of the person or persons who may wear it
• It is capable of fitting the wearer correctly after adjustments within the range for which it is designed
• So far as is practicable, it is effective to prevent or adequately control the risk or risks involved without increasing overall risk
• It complies with any enactment (whether in an Act or instrument) which implements in Great Britain any provision on design or manufacture with respect to health or safety in any relevant Community directive listed in Schedule 1 which is applicable to that item of personal protective equipment.

[Personal Protective Equipment at Work Regulations 1992]

Compatibility

Where there is the presence of more than one risk to health and safety with a resultant need for the use of more than one item of PPE simultaneously these individual items must be both effective against the risk and fully compatible. Some manufacturers supply fully integrated systems encompassing head, hearing, eye and respiratory protection to ensure that these items can be easily sourced.

The integrity of PPE equipment can only be verified when there is suitable compatibility of protective products in manufactured condition and under no circumstances should PPE equipment be modified or adapted. Drilling a hole in a protective helmet or attaching unsuitable ear defenders can severely undermine the performance characteristics of the item of PPE. In turn this will negate both the legal compliance of the product and the suitability for use under the Regulations.

All employers have an obligation to ensure regular maintenance of any PPE equipment supplied to ensure it is in an efficient state, in efficient working order and in good repair. Head protection should be periodically checked for damage such as cracks, serious scratches and dents and be replaced whenever necessary; the usual recommendation is every two years (or sooner if required).

Table 3: Test performance data