Thousands of workers each year suffer from work related eye injuries that range from minor injuries like dust in the eye resulting in temporary conjunctivitis, to serious injuries that cause the loss of one or both eyes.
Section 8 of the Occupational Health and Safety Act stipulates the general duties of employers to their employees in South Africa and determines the following:
Every employer shall provide and maintain, as far as is reasonably practicable, a working environment that is safe and without risk to the health of his employees.
It also requires the employer to provide, free of charge, any personal protective equipment (PPE) required to enable employees to perform work safely and without risk to health. Therefore the employer must provide eye and face protection where the risk to injury or disease exits to protect such an employee against the following hazards: radiological, chemical, environmental or mechanical irritants in the work place.
Risk and PPE assessment
As with everything else in health and safety in the workplace, protecting the face and vision of an employee starts with a risk assessment. When assessing the workplace and implementing control measures other means of protection should always be considered before resorting to PPE. If the hazards cannot be controlled by other means such as engineering controls and the hazard necessitates the use of eye and face protection, the employer needs to ensure that the correct PPE is issued to prevent exposure or harm to the individual.
Pictograms, demarcation, emergencies
PPE should always be used in conjunction with guards, sound manufacturing processes and proper engineering controls in order to protect the worker optimally. As with colour coding, demarcation is used to convey a message or warning to the employee in the workplace. All hazardous areas where the risk of eye or face injury exists must be highlighted for easy recognition, with the appropriate and correct pictograms and demarcation of the hazardous area. The pictograms should indicate where the usage of eye or face protection is mandatory. Informative pictograms should be displayed at all emergency showers and eye wash fountains. Employees should be trained to recognise the meanings of the different pictograms and demarcation areas and where to find all emergency equipment, as well as which procedures to follow under different emergency conditions.
Eye injuries and diseases
As detailed in the following sections, workplace eye injuries and diseases include cataracts caused by workplace exposure, changes to depth, contrast and colour of vision.
Cataracts caused by workplace exposure
A cataract is a clouding of the clear lens of the eye. Cataracts are mostly age related. Ultraviolet B (UVB) radiation exposure of the eye increases the risk of getting cortical or nuclear cataracts. Exposure to sunlight, welding arc and infrared radiation are all contributing factors in cataract formation in the work place and such cataracts are a reportable disease to the compensation commissioner in South Africa.
Some individuals are exposed to greater than normal amounts of ionising radiation and are also at risk of cataract formation. Radioactive materials give off ionising radiation and certain occupations are at higher risk of ionising radiation than others. Examples of such occupations are astronauts, industrial and nuclear power plant workers and x-ray operators.
Employees at risk of cataracts because of their occupations should be placed under medical surveillance and screened for cataracts, at least annually, by the occupational medical practitioner.
Depth and contrast
Vision works in stereo. The brain combines the image of the left and right eye into one image, which gives a person depth perception. If a person closes one eye, the brain will only receive half the information required to determine distance. Losing sight in one eye, therefore, will cause loss of depth perception. A person who loses sight in one eye, such as in an industrial accident, will be able to draw on past experience to contextualise the position of objects related to their size; e.g. a bird appearing larger than an aeroplane is a case of the bird being nearer and the aeroplane further away from a person.
Often sight defects from birth will affect both eyes in some way. If one eye has good visual acuity and a full visual field in the good eye is present, there is no reason for such a person not to drive a vehicle, as they will learn from childhood to rely on monocular clues for distance and depth perception.
The loss of depth perception causes a significant effect on an individual and is closely related with the loss of contrast. Loss of contrast refers to the inability to distinguish between shades that are close in colour. Some may experience loss of contrast that further darkens the dark parts of an image, while others may experience the overall image becoming greyer – to such a point that the sharp edges merge into the grey of the rest of the image. The edges of a staircase, for example, may not be as visible, posing a hazard of missing the step. Uneven surfaces and loss of depth perception may lead to an individual who may not be able to determine the depth of the depressions in the surface when walking, leading to missed footing.
Work place conditions that can result in impact objects, dust or other foreign bodies entering the eye should be prevented at all costs. Face and eye protection should be selected in such a way as to first identify the type of hazard and then to ensure that the face and eye protection will give the maximum protection to such a hazard.
Usually inherited, colour blindness is a condition whereby an individual is unable to clearly distinguish between different colours of the spectrum. Achromatopsia is the total inability to distinguish colours and is very rare. Normal colour vision requires the cones (specialised receptor cells in the retina of the eye) to be free of defects. To enable a person to see a wide spectrum of colours there are three types of cones: red, blue and green.
Colour blindness is sometimes acquired through chronic illness such as diabetes mellitus, leukaemia, glaucoma, liver diseases, chronic alcoholism, macular degeneration, and retinitis pigmentosa. Occasionally changes in the eyes above the age of 60 may cause loss in colour vision.
Damage to the brain, accidents or illness may lead to loss in colour vision. Certain medication can also cause loss in colour vision; for example, antibiotics, anti-hypertensive medication, anti-tuberculosis drugs or barbiturates.
Inherited colour blindness cannot be cured. In some instances, such as when the use of medication is the cause, by removing the cause the loss can be reversed.
Workplace eye injuries resulting in damage to the retina can result in permanent loss of colour vision. Workplace injuries should be addressed in the risk assessment, therefore, and issuing of correct face and eye protection should be ensured to prevent eye injuries – specifically eye injuries that can damage the retina.
When selecting eye and face protection one should consider the following requirements and limitations:
• Protector selection and fitting
• Welding helmets, hand shields and face shields
• Spectacles – metal, plastic and combination
• Eye cups – for chippers, welders and cutters, to protect against dust and splashes
• Attachments and auxiliary equipment such as lift fronts, chin rests, snoods, aprons, magnifiers, and permanent side shields on eyewear
The risk assessment and man task observations should play a leading role in the selection of PPE. The risk assessment should also consider employees wearing prescription eyewear and contact lenses.
Other factors to consider in the selection of impact resistant eyewear include:
• Level of protection required
• Ease of repair
• Resemblance with more attractive, regular eyewear
• Weight of the eyewear
• Compatibility with prescription eyewear
• Sweat bands to help prevent eye irritation and aid visibility
• Fog accumulation
Fog accumulation can cause impaired vision and if such a hazard exits, one should consider providing employees with anti-fogging eyewear. If this is not possible, defogging material and wiping tissues along with a receptacle for discarding the waste should be provided.
Note that face shields cannot be used as basic eye protection against impact and should be combined with impact eye protection when such a risk exists.
Protective eyewear should be fitted as close to the eyes as possible, but one should take care that the eyelashes do not make contact with the lenses of the eye protection in order for it to give the widest possible field of vision.
Cup protective eyewear should have cups large enough to protect the eye socket and also have the ability to distribute any impact over a wide area of the facial bones. It should be flame resistant, corrosion resistant and non-irritating to the skin.
Welding lenses should always be shielded by a cover lens and should be protected by a transparent, durable coating if exposed to pitting from grinding wheel sparks.
Data from accident investigations and studies suggest that contact lens wearers do not appear to have problems when using the correct protective eyewear in conjunction with their contact lenses in the workplace. Work environments where the employees are exposed to chemicals, vapours, splashes, radiant or intense heat, or a high particulate atmosphere should be considered a higher risk for contact lens wearers and they should be issued with prescription safety eyewear, rather than combining the contact lenses with general protective eyewear.
Visitors and employees should be informed during the induction training of areas where contact lens use is allowed and where it is restricted. The induction training should include the instruction to remove contact lenses immediately if redness of the eyes, blurred vision, or pain in the eyes occurs when using contact lenses in a demarcated eye protection usage area. It is also recommended that employees and visitors keep a spare pair of contact lenses available should they damage or lose a lens while working. If contact lenses are allowed in certain work areas, these areas should be specified. Management should include the use of prescription eyewear, be it spectacles or contact lenses, in the PPE Policy.
A document should exist that lists all employees that wear contact lenses and access control should check whether visitors wear lenses, in case of an eye emergency incident occurring in the workplace. First aid and medical personnel must be trained and declared competent in the correct procedures and use of equipment to remove both hard and soft contact lenses from conscious and unconscious workers.
In addition to physical and chemical agents, welders are subjected to radiant energy (ultra-violet as well as visible and infrared bands of the spectrum) that can cause adverse health effects to the eyes. All welding presents problems, especially within the field of controlling infrared and visible radiation. Depending upon the flux used and the size and temperature of the pool of melted metal, the welding process will emit both infrared and visible radiation. The proportion of exposure in the visible range increases as the temperature rises. Additional problems are created in the control of UV radiation in instances where heavy-gas welding and cutting operations take place, as well as where arc cutting and welding exceeds 30 amperes.
Where only glare was identified as a hazard, eye protection with mild filter shade lenses or polarising lenses and opaque side shields offers adequate protection. In instances where hot metal may spatter or where visible glare must be reduced, however, one must specify that a plastic face shield must be worn over mild filter shade spectacles with opaque side shields.
To obtain the added advantage of protecting the eyes from other welding operations or even from accidental arc exposure when the helmet is raised, one can combine the shade of the plate in a welder’s helmet with the shade of the safety eyewear worn underneath the helmet.
Protective lenses should be installed in a handheld shield or welder’s helmet to protect against UV and infrared radiation and visible glare in inspection operations. Care should be taken that the shield is made of non-flammable material, which is opaque to dangerous radiation and a poor conductor of heat.
Laser beam protection
The use of safety eyewear in an environment where laser beams are used may cause a false sense of security. For certain occupations, however, specifically designed eyewear is essential, such as for laser technicians and researchers who need to wear eye protection to protect against laser beam exposure.
One requirement to keep in mind is that because of the wide spectrum of laser wavelengths, no single type of eye protection will offer protection from all wavelengths. It is necessary to know the type of laser wavelengths when selecting the anti-laser eyewear. Also keep in mind that laser safety eyewear exposed to intense energy or power density levels may lose effectiveness and should be discarded. To ensure ultimate protection, operators should be shielded from the laser beam by the use of engineering controls.
Acid hoods and chemical protection
Face shields should be shaped in such a way that they cover the whole face and should be selected while keeping the hazard in mind. The shield should be supported by a headband so that the user can tip it back and clear the face easily. The user should also be able to readily remove the hood or face shield in case it becomes contaminated with corrosive or other hazardous chemicals. A hood that is made of chemical-resistant material with a glass or plastic window will give adequate protection – provided that if replaceable inner and outer windows form part of the hood, secure joints between the windows and the hood material exists. For severe exposure potential, the worker should wear a face shield together with flexible-fitting chemical eyewear.
The general rule is that face protection should always be used in conjunction with suitable basic eye protection. The basic styles of face shields protecting the face, eyes and neck from flying particles, molten metal and chemicals are:
• Headgear without crown protectors
• Headgear with crown protectors
• Headgear with crown and chin protectors
The face shields are available with one of these replaceable window styles:
• Wire screen
• Tinted transparent
• Clear transparent
• Combination of plastic and screen
• Fibre window with a filter plate mounting
When selecting face shields and hoods one should ensure that the materials used in manufacture combine mechanical strength and the ability to withstand frequent disinfecting operations with light weightiness and non-irritation to the skin of the user. The shield should be manufactured from non-corrosive metals and slow burning plastics and only optical grade plastic, which is free from flaws or distortions, should be inserted for the windows.
The policy must be approved and signed off by top management and should clearly state the need for and correct use of PPE. It should:
• Provide guidelines on the selection of PPE
• Be communicated to all employees and visitors as needed
• Indicate measures taken to enforce the usage of PPE
• Indicate the training programme in place for the usage of PPE for all hazards identified
• Provide guidelines on the inspection, use and maintenance of different types of PPE used within the company
• Discuss how to deal with the different types of emergencies that may emerge in and around environments where the use of PPE is required
• Discuss the capabilities and limitations of the PPE selected by the company for the different types of hazards present
• Discuss how the PPE will be paid for
Published: 21st Jul 2015 in Health and Safety Middle East