Anne Helmenstine refers to chemicals as any substance consisting of matter. This includes any liquid, solid or gas. There are two types of chemicals: chemicals that occur naturally and those that are made artificially.
Naturally-occurring chemicals can be solid (i.e. plant fibres, animal bones, rocks, and soil or minerals such as copper or granite); liquid (i.e. water that is made up of hydrogen and oxygen); or a gas (i.e. hydrogen).
There are many types of artificially made chemicals. Combining copper and tin, for example, creates a malleable metal called bronze. During the industrialisation period combinations of elements resulted in the creation of stainless steel, foils, lightweight aluminium and other heavy metals. Artificial chemical compounds are used to flavour food, to create a range of textures in food from crunchy to chewy to smooth, and are even used in the pharmaceutical industry. Chemical preservatives such as nitrates are also added to food to increase the shelf life of the products.
other heavy metals. Artificial chemical compounds are used to flavour food, to create a range of textures in food from crunchy to chewy to smooth, and are even used in the pharmaceutical industry. Chemical preservatives such as nitrates are also added to food to increase the shelf life of the products.
“it is the employer’s responsibility to implement the roadmap set out in the risk assessment”
Chemical risk assessment
The intention of the risk assessment should be to prevent accidents and ill health in the workplace. Control measures should be the outcome of the risk assessment and must be specified in writing. It is the employer’s responsibility to implement the roadmap set out in the risk assessment in order to adequately safeguard employees against accidents or ill-health in the workplace. The following guidelines can be used when executing the chemical risk assessment.
Identify the substances
The first step is to identify the substances to which employees are exposed. These can be:
- Raw materials
- Substances generated or emitted during the production process and / or final product
Next, identify all employees who might be exposed: maintenance workers, production workers, operators, cleaners, contractors and even visitors.
Identify potential harm
Identifying the possible harm that chemicals may cause can be achieved using Material Safety Data Sheets (MSDS) and packaging labels as a critical part of the assessment. Possible hazards or risks to consider: fire, explosion, irritant, asthma, dermatitis, carcinogenic, asphyxiant, corrosive, mutagen or teratogen, and organ specific damage.
When assessing these hazards and risks it may be necessary to involve different parties of the multi-disciplinary team, such as the safety officer, occupational health team, occupational hygienist, environmental manager, suppliers, plant engineer, plant supervisor, and plant manager.
Furthermore, hazards and risks should be divided into short- and long-term exposure effects.
Identify activities giving rise to exposure
Under which circumstances does a possibility exist that a spillage or splash may occur? And what conditions can give rise to circumstances where a substance can be inhaled, swallowed, or absorbed through the skin?
Identify the risks to control
To determine the significance of the exposure, consider the following:
- Duration and frequency of the exposure
- Concentration of the substance or substances involved
- The consequences should exposure happen
In addition, identify the possible malfunctions or accidents that could take place that can result in serious exposure.
Specify measures in writing
Specify the control measures in writing after consulting with different members of the multi-disciplinary team. These controls should be measured against current industry practices, legislative requirements and standards.
The golden rules for establishing and implementing controls are:
- Eliminate the risk
- Substitute the chemical with a less hazardous chemical
- Engineering controls, i.e. local exhaust ventilation
- Administrative controls
- Personal protective equipment, which should always be the last resort for control
Address PPE’s limitations
Limitations of PPE also need to be addressed during the chemical risk assessment. These can be split into safety hazards and management requirements.
- Movement of the employee may be restricted due to the nature of the PPE
- Visual fields may be restricted because of the visual field limitations that are caused by using PPE
- Communication can be impaired because of the usage of face and respiratory protection and can even be worsened due to workplace noise
- Psychological stress resulting from the confining nature of the chemical protection suits needs to be assessed by a competent person and an employee who is suffering from claustrophobia should be restricted from working in such chemical protection wear or inside confined spaces
- Heat stress and the risk of dehydration should be properly assessed – if the highest levels of chemical personal protection are required, keep in mind that such an employee can also not wear the personal protection for longer than 30 minutes continuously: administrative controls should be put into place to limit the exposure time to include rest cycles in a cool environment. During such rest cycles, the employee must be encouraged to take at least 600ml of clean drinking water per hour to prevent dehydration
Management should establish a PPE programme that ensures effective use of PPE:
- Training in the correct usage of PPE
- Employees should be discouraged from growing facial hear, like a beard or a moustache that could interfere with the proper fit of a mask or respirator
- Prevention of improper use and penetration of PPE should be encouraged and should be included in the training programme
Selecting the correct PPE
When selecting PPE, one should bear in mind that there is no single combination of personal protective equipment and clothing that can protect an employee against all hazards. PPE is designed to provide employees with protection that can result in workplace hazards that could lead to injuries and/or occupational illness. Examples of such hazards can be chemical, radiation, physical and mechanical exposure in the workplace. When assessing these workplace hazards for chemical PPE selection, hazards affecting the respiratory system, the skin, eyes, face, hands, feet, head, body and hearing should be considered.
“heat stress and the risk of dehydration should be properly assessed”
Four levels of PPE
Level A PPE is used “when the greatest level of skin, respiratory, and eye protection is required” and consists of:
- Positive pressure air respirator with emergency self-contained breathing apparatus that is approved by the National Institute for Occupational Safety and Health (NIOSH) – a full face-piece self-contained breathing apparatus with positive pressure can also be used
- Inner and outer chemical resistant gloves shall be used
- Coverall as indicated by the HIRA
- Long underwear as indicated
- Fully protective chemical suit
- Hard hat to be worm under the protective suit
- Safety boots with a chemical resistant steel-toe and the boot shank (the supportive structure between the insole and outsole) must also be of steel
- A disposable protective set of suit, gloves and boots that can be worn over the protective suit
- Positive pressure air respirator with emergency self-contained breathing apparatus that is approved by the National Institute for Occupational Safety and Health (NIOSH)
- Double-layered chemical resistant gloves
- Chemical resistant clothing
- Safety boots with a chemical resistant steel-toe and the boot shank (the supportive structure between the insole and outsole) must also be of steel
Level C PPE is selected if the concentration and type of the airborne substance is known, and the criteria for using air purifying respirators are met and consist of:
- Air purifying full-face or half-mask respirators that are approved by the National Institute for Occupational Safety and Health (NIOSH)
- Chemical-resistant clothing that includes a hood-two-piece chemical splash suit and disposable chemical resistant overalls
- Inner and outer chemical resistant gloves
- Safety boots with a chemical resistant steel-toe and the boot shank (the supportive structure between the insole and outsole) must also be of steel; the outer boot covers must be chemical-resistant
- The following can be added as needed: escape mask, face shield, hard hat, coveralls
Level D PPE is used in cases of “nuisance” contaminants and offers minimal protection to the employee: chemical resistant steel toe and shank boots, disposable boot covers, coveralls, gloves, safety glasses.
The following can be added as needed: escape mask, face shield, and hard hat.
“Biological monitoring” means a planned programme of periodic collection and analysis of body fluid, tissues, excreta or exhaled air in order to detect and quantify the exposure to, or absorption of, any substance or organism by persons. Biological monitoring measures how much of the chemical has been absorbed into the body of an exposed or potentially exposed person.
Biological monitoring is the systematic collection and analysis of a biological specimen such as hair, blood, nails, etc. for the presence of an indicator of exposure or response in the worker. Biological monitoring may be contrasted with environmental monitoring, which uses an ambient environmental compartment (air, water, soil) as the sampled medium. Biological monitoring permits estimates of internal absorbed dose and environmental monitoring leads to estimates of external exposure, but, although different in sampling methods and purpose, the two types of monitoring are complementary: their results should be correlated.
Many jobs involve using chemicals which can harm the health of employees if they are not properly handled. The rate and amount of contaminant taken up by the body depends on factors such as:
- Size and nature of the contaminant
- Atmospheric conditions
- Breathing rate of the worker
- Whether a respirator or other protective wear is worn
- Whether the chemical can enter the body via routes other than breathing, such as through skin or ingestion
- Individual differences such as personal hygiene habits, age, gender, genetic susceptibility and fitness level
Actual exposures can be determined using biological monitoring. It is important to understand the meaning and limitations of biological monitoring results, as presence within the body does not necessarily correlate with occupational exposures or symptoms or damage to health.
“Biological effect monitoring” is the measurement and assessment of early biological effects and changes in the body and the organs of the body by absorption of a chemical.
Many include “biological effect monitoring” and “biological monitoring” under the same umbrella where in fact what is measured indicates the difference between the two types of tests:
- Biological effect monitoring tests for end organ damage, i.e. doing a full blood count or liver functions
- Biological monitoring tests for the actual chemical or chemical metabolite, i.e. testing for toluene or testing for the metabolite of tetra-bromoethane which is bromide
Biological monitoring tests for the actual substance within the body and can be useful in monitoring the effectiveness of the PPE used in the workplace.
Medical examinations for chemical exposed employees
Medical Surveillance is a planned programme of medical examinations on employees exposed to hazards that may have a long-term health effect on them and can entail six monthly, annual, biennial or even longer intervals, depending on the exposure period. The surveillance may consist of clinical examinations, biological monitoring or any other medical testing as deemed necessary by either the Occupational Health Doctor (OMP) or Occupational Health Nursing Practitioner (OHNP). The purpose of a medical surveillance programme is to prevent, detect or even treat occupational diseases.
The principal concern of the employer on the outcome of the Medical Surveillance Programme is the Medical Certificate of Fitness, or so-called Fitness Declaration Certificate. One needs to understand that Medical Surveillance is about the healthy employee at work. Complicating issues are primary health care problems like high blood pressure, high blood sugar, epilepsy and so on, in other words, your healthy employee on chronic treatment. The OMP must therefore set up a minimum medical standard of fitness for the OHNP to follow – defining the concept of “normality” and setting clear guidelines for the OHNP to follow in cases of “abnormality”. This includes notifying line management that some problem exists, that needs to be addressed as a “risk towards the health and safety” of the said employee or may even involve risk towards co-workers.
It is imperative that when the employer sends the employee for medical surveillance and fit to work certification, to send the Occupational Risk Exposure Profile (OREP) (also called the Man Job Specification). The OREP ensures that all hazards that may be present in the workplace are properly addressed during the medical examination of such an employee. Special care needs to be taken when examining Level A and B PPE employees, as the PPE in itself may pose a threat towards the health and safety of an employee. Heat stress is one hazard that needs to be considered during the medical examination of such employees. Heavy manual labour, combined with the usage of Level A or B PPE, will lead to an increase in the metabolic rate of the human body, which in turn may lead to heat overload in the human body. Therefore, it is imperative that the Occupational Health Practitioner should be familiar with the environment and job of employees that need to be declared fit to work in order to provide maximum health care and minimise workplace hazards. This can only be done if the OREP is available prior to starting with the medical examination.
Medical examination risk profile for Level A and B PPE employees (this includes employees who will be expected to perform work in an acid suit), needs to include at least the following:
- Workplace occupational history
- Medical history with the emphasis on type of medication used that is likely to increase heat illness. It is imperative that all employees should report to the medical station with their medication or a list of their medication. Below is a list of medication that may increase the likelihood of heat illness when exposed to a WBGT index of > 30° Celsius: drugs of abuse, anaesthetic agents, anticholinergics, antidepressants, antihistamines, anti-hypertensives (sympatholytic), ß-blockers, diuretics, bipolar disease, monoamine-oxidase inhibitors (MAOIS), phenothiazine antipsychotics, salicylates, stimulants, sympathomimetic, thyroid hormone •
- Social habits that includes alcohol and substance use
- History of previous heat disorders: heat rash, heat cramps, heat fatigue, heat exhaustion, heat stroke
- Older than 50 years
- The client is pregnant
- BMI index is ≥ 30 or ≤ 16
- JACCOL: jaundice, anaemia, clubbing, cyanosis, oedema or lymphadenopathy
- Cardiovascular abnormalities: Gross cardiovascular abnormalities require a full investigation
- The employee is using antihypertensive medication or is a known diabetic on insulin, tablets or both
- The lung function / chest x-ray is abnormal
- There are any rashes / furuncles / cellulitis of the skin
- The origins of proteinuria, glycosuria and haematuria should be established and assessed
“biological monitoring tests for the actual substance within the body and can be useful in monitoring the effectiveness of PPE”
Fitness declarations based on the above risk profile should follow a threefold approach:
- If the risk profile features only one of the above elements, (especially if the risk can be controlled), fitness should be regarded as “acceptable”.
- If the risk profile features two of the above elements, it should be viewed with concern and an employee should rather be restricted from working in Level A and B PPE or where the WBGT index exceeds 30°C unless the situation can be improved.
- If the risk profile features more than two of the aforementioned undesirable elements, it constitutes an unacceptable risk and the employee should be restricted from working in Level A and B PPE, or where the WBGT index exceeds 30°C.