Enquête sur l’hygiène Copy

Hygiene Survey

An occupational hygiene survey anticipates, identifies, and quantifies hazards in the workplace to formulate controls that match the severity of the exposure and risk⁴. The main purpose of an occupational hygiene survey is to communicate measures for the control of an exposure/s that could cause harm or adversely affect health, to provide legitimacy to the control measures recommended, be based on scientific evidence to support the conclusion that a health risk is of sufficient severity to warrant the extent/magnitude of controls recommended.

Since most illumination measurements and recommendations for lighting levels are given in units of illuminance, called Lux (lx) levels, a device that measures Lux directly is required. A Lux (or light) meter is generally used to measure lighting levels. The light meter is a photoelectric device that causes an electric current to flow in the measuring circuit and this current is registered on a suitably calibrated meter. An occupational hygienist is involved with a hygiene survey that assesses, measures and controls physical, chemical, biological or environmental hazards in the workplace which could cause injury or disease. Physical hazards include noise, thermal stress, illumination extremes, ionizing or non-ionizing radiation and ergonomics.

Although there are many aspects to occupational hygiene (work) the most known and sought after is in determining or estimating potential or actual exposures to hazards such as noise, lighting, and chemical measurement. Several methods can be applied in assessing the workplace or environment for noise which is a physical hazard.

The main steps outlined for assessing and managing occupational exposures⁶:

Basic Characterisation (identify agents, hazards, people potentially exposed and existing exposure controls)
Exposure Assessment (select occupational exposure limits, hazard bands, relevant toxicological data to determine if exposures are “acceptable”, “unacceptable” or “uncertain”)
Exposure Controls (for “unacceptable” or “uncertain” exposures)
Further Information Gathering (for “uncertain” exposures)
Hazard Communication (for all exposures)
Reassessment (as needed) / Management of Change

Identification of visual or ocular hazards:

Flying debris often found in manufacturing, mining and other industries which have loose materials or materials that are being cut, welded, or brazed. In addition, areas in manufacturing, mining and construction industries create significant falling object debris which can cause eye injuries. Grinding operations release fine particles or sharp shreds that can cause eye injuries by embedding or penetrating the eye. Projectiles in any form, size, or shape, and may travel at high or low velocity.

Common projectiles include pieces of screwdriver blades, drill bits, grinding wheels, metal debris, rock, and steel rods, many of which pose a risk to the eyes.

Dusty environments are of the more common causes of workplace eye injuries is the presence of naturally occurring dust particles or particles created by work activities.
Heat: injuries resulting from exposure to extreme temperatures, splashes of molten metal, or hot sparks include burns. Workplaces that have these types of hazards involve pouring, casting, hot dipping, furnace operations and other similar activities.
Impact tools such as staple and nail guns pose a significant visual threat to employees. These hazards can cause severe and permanent eye injuries.

Chemicals: Specific hazards from chemicals occur most frequently during mixing and pouring chemicals from splashes, mists, vapours, or fumes. A chemical substance can enter the eye from this type of exposure. Damage from chemical substances contacting the eyes can often be extremely serious and irreversible.
Biological pathogens: Infections can be transmitted via the mucous membranes of the eye following direct exposure through blood splashes, respiratory droplets generated during coughing or suctioning, or from touching the eyes with contaminated fingers or objects from blood and body fluids (hepatitis or HIV).
Radiation: Radiation (infrared radiation (IR), visible light, ultraviolet (UV) radiation and heat) from molten materials, particularly glass and metal are the primary sources of IR. Laser work and other similar operations create high concentrations of heat, ultraviolet, infrared and reflected light radiation. Laser radiation and welding operations are two main areas of concern in the workplace. Unprotected laser exposure may result in retinal burns, cataracts, and permanent blindness. commonest UV source in industries. Other ocular problems associated with welding include foreign objects entering the eye and eye injuries resulting from the explosions. Sunlight is a major source of an individual’s total exposure to UVB radiation. Individuals working outdoors during the day are at higher risk of developing eye damage such as cataracts and pterygium due to chronic high exposure to solar UVB.

Computer Vision Syndrome (CVS): technology has changed the way we do business, shop, receive information and entertain ourselves. Desktop and mobile device screens reach across all industries, accelerating consumer transactions and changing business operations. eye strain symptoms can occur when eyes are focused on a digital device for two or more consecutive hours per day. It causes physical discomfort which includes dry, burning, itchy eyes. The strain on the eyes can cause blurred vision, headaches, and fatigue

Health effects (clinical signs and symptoms) of certain chemical and physical agents are not evident until maximum exposure is reached.6 Occupational exposure to ionising radiation, chemical agents and some physical agents such as heat, humidity, and optical radiation are controlled by setting limits (maximum permissible exposure) at a fraction of the threshold limit values (TLV) which result in clinical onset of adverse effects.⁶ Therefore, it becomes critical that occupational health and safety programmes include visual task assessments by optometrists that assess the visual functioning required for specific tasks and the associated eye impacts they may have.

Ways to control eye injury hazards
Reduce the risk of eye injury by controlling the potential hazards.

Replace high-risk equipment and toxic chemicals with safer alternatives wherever possible.
Move high-risk equipment to an isolated area.
Install safety barriers.
Maintain equipment and make sure all safety devices, including guards or shields, are in good working order.
Signpost work areas and equipment that require eye protection.
Use water to dampen dusty environments.
Manage fumes or dust with exhaust hoods, extractor fans or similar.
Read the Material Safety Data Sheet (MSDS) that the manufacturer supplies with the hazardous substance and comply with all instructions.
Run regular safety training sessions for the workers.
Provide adequate first aid equipment.

Illumination Measurements
All industrial settings require proper lighting to make tasks easier. Whether in a workshop, a mine or in offices employees receive about 85% of their information through sight. Appropriate lighting, without glare or shadows, reduces eye fatigue and headaches; it prevents workplace incidents and accidents by increasing the visibility of moving machinery and other safety hazards. Illumination can be defined as the use of light brighten or light up an area. Regulation 3 of the Environmental Regulations for Workplaces in the OSH Act and Sections 9 and 15 of the Mine Health and Safety Act, states that a “workplace must be illuminated as per the task-specific minimum levels, which are specified in the Regulations’ Schedule”^21,22.

SANS 10114-1:2020 Interior lighting Part 1: Artificial lighting of interiors. The aim of this standard is to provide basic guidelines and recommendations for the creation of good viewing conditions and a comfortable visual environment to facilitate productivity²². SANS 10114 recognizes the need for good energy management and cost-effective lighting schemes, the provision of sufficient illuminance on a task is a necessary element, the creation of conditions of visual comfort which workers require to maintain efficiency throughout the entire work period. In many instances this depends on the quantity of light, distribution of light throughout the workplace, glare, the luminance of surfaces such as walls, floors, ceilings and equipment and the control of unwanted reflections. SANS 10114-2:2020 Edition 2 Interior lighting Part 2: Emergency lighting²³ to provide basic guidelines and recommendations for the creation of emergency lighting in the workplace.

The lighting requirements of the Environmental Regulations for Workplaces, OSH Act and MHSA include the following:

Illumination surveys should be done by an approved inspection authority (AIA).
Illumination measurements must be done during the day and at night depending on shifts worked.
The average illuminance at any floor level in a workplace, within five metres of a task, must not be less than one-fifth of the average illuminance on that task.
Glare must be reduced to a level where it does not impair vision.
Lamps must be free from flickering that may cause dangerous stroboscopic effects on rotating machinery.

The stroboscopic effect of rotating machinery should be eliminated.
Luminaires and lamps must be kept clean.
Defective luminaires and lamps must be replaced.
Workplaces should have a sufficient amount of light, suitable for the task.
Lighting in a workplace must be uniformly distributed.
Workplaces must be free from glare that may impair vision.

Emergency sources of lighting must be provided where people habitually work at night.
The Environmental Regulations do not stipulate the time periods between each illumination survey. However, the OHSA and MHSA require that HRA and hygiene surveys of risks be performed every 2 years. For this reason, best practice accepts that the illumination levels should be measured every two years or when changes to installations occur. Furthermore, they must be done within 6 months of the establishment of a workplace.
The survey should be repeated when new machinery, or work processes are implemented, or new workplaces commissioned.
The results must be recorded and stored for forty (40) years
Vision protection and welfare programmes should be implemented in all areas where the visual risk exists.


The Path to Prevention
When an employer is fully committed towards preventing vision loss and eye injuries, employees are far more likely to follow this lead and be proactive in terms of protecting their own eyes.

Figure 5.3 Glare: Do You Know the Essentials? ¹⁷