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Börja nu gratis 5b. Occupational Exposure Health_students copy.pdf
Summary
# Definitions and routes of exposure to occupational hazards
This section clarifies fundamental safety terminology and outlines the primary pathways through which workers can encounter hazardous substances in their work environment.
### 1.1 Defining key safety terms
Understanding the distinction between hazard, danger, and risk is crucial for effective workplace safety management [5](#page=5).
#### 1.1.1 Hazard
A hazard is defined as a source or situation that possesses the potential to cause harm. This harm can manifest as human injury, ill health, damage to property, environmental damage, or a combination of these. Hazards can originate from various sources, including "tools" or "work processes" [2](#page=2).
#### 1.1.2 Danger
Danger refers to the relative exposure to a hazard. It represents the harmful condition created by a hazard; essentially, an unsafe situation [3](#page=3) [4](#page=4) [5](#page=5).
#### 1.1.3 Risk
Risk is a composite measure, defined as the combination of the likelihood of a hazardous event occurring within a specific period or under particular circumstances, and the severity of the injury or damage to health, property, or the environment caused by that event. It encapsulates both the probability and the consequence of harm [3](#page=3) [5](#page=5).
> **Tip:** The term "imminent danger" under Section 15 of OSHA 1994 is specifically defined as a serious risk of death or serious bodily injury caused by any plant, substance, thing, or circumstance in the workplace [4](#page=4).
### 1.2 Routes of exposure to occupational hazards
Hazardous and dangerous substances can enter the human body through several distinct routes in the workplace [7](#page=7) [8](#page=8).
#### 1.2.1 Inhalation
Inhalation is the process by which airborne hazardous substances are breathed into the lungs [10](#page=10) [8](#page=8).
**Workplace Precautions:**
* Wear respiratory protection suitable for the specific substance being handled [8](#page=8).
* Implement effective exhaust ventilation systems [8](#page=8).
* Utilize fume and dust extraction equipment [8](#page=8).
#### 1.2.2 Ingestion
Ingestion occurs when hazardous substances are taken into the body through swallowing. This can happen accidentally via contaminated hands, food, or drink [10](#page=10) [8](#page=8).
**Workplace Precautions:**
* Refrain from eating, drinking, or smoking while working in areas where hazardous substances are present [8](#page=8).
* Practice good personal hygiene, including thorough hand washing before eating or drinking [8](#page=8).
#### 1.2.3 Dermal contact
Dermal contact involves substances coming into contact with the skin, which can lead to various forms of exposure [10](#page=10) [9](#page=9).
##### 1.2.3.1 Absorption through the skin
Some hazardous substances can penetrate the skin and enter the bloodstream. This is a common route of exposure for substances like paints and agricultural chemicals [9](#page=9).
**Risk Occupations:** Painters, farmers [9](#page=9).
**Workplace Precautions:**
* Wear appropriate protective gloves [9](#page=9).
* Promptly wash any contaminated skin areas with soap and water [9](#page=9).
* Utilize barrier creams to protect the skin [9](#page=9).
##### 1.2.3.2 Direct entry through open cuts and wounds
Hazardous substances can directly enter the body through pre-existing breaks in the skin, such as cuts and wounds [9](#page=9).
**Workplace Precautions:**
* Ensure all cuts and wounds are promptly treated and properly dressed [9](#page=9).
* Keep all cuts and wounds covered securely while at work [9](#page=9).
---
# Occupational health concepts and services
Occupational health focuses on promoting and maintaining the highest degree of physical, mental, and social well-being for workers across all occupations by preventing health deviations, controlling risks, and aligning work with people and people with their jobs [12](#page=12).
### 2.1 Occupational health principles and determinants
Occupational health broadly addresses all aspects of health and safety within the workplace, with a significant emphasis on the primary prevention of hazards. Several factors influence worker health, including workplace risks that can lead to conditions such as cancers, accidents, musculoskeletal diseases, respiratory issues, hearing loss, circulatory problems, stress-related disorders, and communicable diseases. Beyond immediate workplace hazards, employment and working conditions in both formal and informal economies are crucial determinants. These encompass working hours, salary, and workplace policies related to maternity leave, as well as provisions for health promotion and protection [13](#page=13).
### 2.2 Focus of occupational health
The core focus of occupational health is multifaceted, aiming to:
* Promote and maintain workers' physical, mental, and social well-being at optimal levels [14](#page=14).
* Prevent illnesses and diseases that arise from the workplace or its associated processes [14](#page=14).
* Enhance the quality of the work environment and work processes to ensure they are suitable for worker safety and health conditions [14](#page=14).
> **Tip:** Understanding these three key focus areas is crucial for grasping the overall mission of occupational health.
### 2.3 Promotion and prevention concepts
Occupational health operates on a dual concept of promotion and prevention, addressing both workplace factors and individual lifestyle choices [15](#page=15).
* **Workplace Factors:** These include hazards, the work environment itself, and equipment or machinery [15](#page=15).
* **Lifestyle:** This encompasses individual habits such as smoking, alcohol and drug abuse, and hobbies [15](#page=15).
These elements are central to both preventing occupational diseases and workplace accidents, and promoting overall worker well-being [15](#page=15).
### 2.4 Disciplines within occupational health
Occupational health is an interdisciplinary field drawing on expertise from various specialized areas [16](#page=16):
* Occupational Medicine
* Industrial Hygiene
* Occupational Toxicology
* Ergonomics
* Epidemiology
* Industrial Psychology
### 2.5 Occupational health prevention and activities
Occupational health employs a hierarchical approach to prevention, encompassing primary, secondary, and tertiary levels of intervention [17](#page=17):
* **Primary Prevention:**
* **Health Promotion:** Encouraging healthy behaviors and improving overall well-being [17](#page=17).
* **Specific Protection:** Implementing measures such as regulations, control measures, immunizations, and universal precautions [17](#page=17).
* **Secondary Prevention:**
* **Early detection of hazards, disease, and provision of early treatment:** This involves health monitoring, first aid, and establishing emergency response plans [17](#page=17).
* **Tertiary Prevention:**
* **Limited disability and rehabilitation:** Activities include disability assessment, physiotherapy, compensation, and back-to-work programs [17](#page=17).
### 2.6 Occupational health at work: key roles
In practice, occupational health at work involves several key activities:
* Identifying and controlling hazards, alongside providing early treatment [18](#page=18).
* Educating both management and workers on their shared responsibility for ensuring and safeguarding safety and health at work [18](#page=18).
* Promoting healthy lifestyle programs among employees [18](#page=18).
### 2.7 Types of occupational health services
A comprehensive range of services is provided within occupational health [19](#page=19):
* Health promotion and education
* Exposure monitoring
* Health risk assessment
* Hazard control
* Occupational fitness assessment
* Medical surveillance
* Suiting the work and work environment to the worker
* General medication treatment
* First aid and medical aid
* Disability assessment
* Data collection, analysis, and recordkeeping
### 2.8 Competent persons and the occupational health team
Effective occupational health services rely on a team of competent individuals with specialized knowledge. These include [20](#page=20):
**Competent Persons:**
1. Safety and Health Officer (SHO)
2. Hygiene Technician
3. Competent Person for Noise
4. Chemical Health Risk Assessor (CHRA)
5. Occupational Health Doctor (OHD)
**Occupational Health Team:**
1. First Aid Officer
2. Ergonomist
3. Toxicologist
4. Safety Engineer
5. Health Promotion Officer
6. Industrial Psychologist
> **Example:** An Occupational Health Doctor (OHD) might conduct medical surveillance for workers exposed to specific chemicals, while a Chemical Health Risk Assessor (CHRA) would evaluate the extent of that exposure [20](#page=20).
---
# Occupational exposure standards and measurement
This topic delves into the essential aspects of occupational exposure standards, including their types, definitions, and the methodologies employed for measuring and calculating workplace exposures, with a particular focus on Time-Weighted Average (TWA) calculations [21](#page=21) [22](#page=22) [23](#page=23) [24](#page=24) [25](#page=25) [26](#page=26) [27](#page=27) [28](#page=28) [29](#page=29) [30](#page=30) [31](#page=31) [32](#page=32) [33](#page=33) [34](#page=34) [35](#page=35) [36](#page=36) [37](#page=37) [38](#page=38) [39](#page=39) [40](#page=40) [41](#page=41) [42](#page=42).
### 3.1 Types of occupational exposure standards
Occupational exposure standards serve as benchmarks to protect workers from the adverse health effects of hazardous substances and physical agents in the workplace. These standards are crucial for maintaining a safe working environment and can be broadly categorized into two main types: voluntary and compulsory [23](#page=23) [24](#page=24).
#### 3.1.1 Voluntary standards
Voluntary standards are typically developed by professional organizations and are not legally binding, although they are widely respected and often adopted as best practices within industries [24](#page=24).
##### 3.1.1.1 Threshold Limit Values (TLVs)
The American Conference of Governmental Industrial Hygienists (ACGIH) is a primary developer of voluntary occupational exposure standards, most notably the Threshold Limit Values (TLVs). TLVs represent the concentration of a chemical substance to which a worker can be exposed, day after day, without adverse health effects [24](#page=24) [26](#page=26).
There are three main categories of TLVs:
* **TLV-TWA (Threshold Limit Value - Time-Weighted Average):** This is an eight-hour time-weighted average value representing the concentration to which workers can be exposed during an eight-hour workday and a 40-hour workweek, without anticipated adverse health effects. The "8-hour reference period" concept treats occupational exposures in any 24-hour period as equivalent to a single uniform exposure for 8 hours [25](#page=25) [35](#page=35).
* **TLV-STEL (Threshold Limit Value - Short-Term Exposure Limit):** This refers to a permissible exposure limit value for a short duration. It should not be repeated more than four times per day, with at least 60 minutes between exposure periods. The STEL is the concentration to which workers can be exposed continuously for a short period without suffering irritation, chronic or irreversible tissue damage, narcosis that increases the likelihood of accidental injury, impairs self-rescue, or materially reduces work efficiency. It is typically a 15-minute time-weighted average concentration thought not to be injurious to health [25](#page=25) [28](#page=28).
* **TLV-C (Threshold Limit Value - Ceiling):** This is the highest concentration value that may not be exceeded at any time throughout the duration of work (#page=25, 29). Ceiling limits are generally higher than TWA values [25](#page=25) [29](#page=29).
##### 3.1.1.2 Biological Exposure Indices (BEIs)
In addition to air standards, there are also biological limits, such as Biological Exposure Indices (BEIs), which are considered in occupational health standards [23](#page=23).
##### 3.1.1.3 Carcinogenic substances
For substances confirmed as carcinogens, specific exposure limits like TWA, STEL, or Ceiling may not be established. These substances are often classified into categories [30](#page=30):
* A1 - Confirmed carcinogenic [30](#page=30).
* A2 - Suspected carcinogenic [30](#page=30).
* A3 - Proven on animals [30](#page=30).
* A4 - No classification [30](#page=30).
* A5 - No signs [30](#page=30).
#### 3.1.2 Compulsory standards
Compulsory standards, also known as legal limits, are mandated by government regulations and must be adhered to by employers [24](#page=24).
##### 3.1.2.1 Permissible Exposure Limits (PELs)
Permissible Exposure Limits (PELs) are legal limits used to measure exposure and are enforceable by regulatory bodies such as the Occupational Safety and Health Administration (OSHA) in the United States (#page=24, 26). PELs can be established as ceiling limits, eight-hour time-weighted average airborne concentrations, or maximum exposure limits (#page=26, 33) [24](#page=24) [26](#page=26) [33](#page=33).
The Occupational Safety and Health Act 1994 (Amendment 2022) and the Occupational Safety and Health (Use and Standards of Exposure of Chemicals Hazardous to Health) Regulations 2000 (USECHH 2000) are examples of regulations that define PELs for hazardous chemicals (#page=31, 33). The Occupational Safety and Health (Noise Exposure) 2019 regulation specifies PELs for noise exposure (#page=31, 32) [31](#page=31) [32](#page=32) [33](#page=33).
### 3.2 Measurement of workplace exposure
Measuring workplace exposure involves collecting air samples within a worker's breathing zone. This is typically done using a monitor attached to the worker's body [22](#page=22).
### 3.3 Calculation of human exposure
Calculating human exposure, particularly the Time-Weighted Average (TWA), is essential for determining if workplace exposures are within acceptable limits [34](#page=34).
#### 3.3.1 Total Weighted Average (TWA) calculation
The TWA refers to the average concentration of a substance in the air over a specified period, usually an 8-hour workday, which is not expected to be injurious to health [27](#page=27).
The general formula for calculating an 8-hour TWA exposure for varying concentrations and durations is:
$$TWA = \frac{\sum_{i=1}^{n} (C_i \times T_i)}{8 \text{ hours}}$$
Where:
* $C_i$ is the concentration of the substance during period $i$ (#page=37, 39, 40, 41) [37](#page=37) [39](#page=39) [40](#page=40) [41](#page=41).
* $T_i$ is the duration of exposure during period $i$ (#page=37, 39, 40, 41) [37](#page=37) [39](#page=39) [40](#page=40) [41](#page=41).
* $n$ is the number of different exposure periods (#page=37, 39, 40, 41) [37](#page=37) [39](#page=39) [40](#page=40) [41](#page=41).
**Note:** Durations ($T_i$) must be in the same units as the reference period (hours). If given in minutes, they need to be converted to hours by dividing by 60.
> **Tip:** Ensure all time units are consistent (e.g., convert minutes to hours) before applying the TWA formula.
**Example 1:** An operator works for 7 hours and 20 minutes in a process with an average exposure of 0.12 mg/m³. Calculate the TWA.
First, convert 7 hours and 20 minutes to hours: $7 + \frac{20}{60} = 7.33$ hours.
$$TWA = \frac{0.12 \text{ mg/m}^3 \times 7.33 \text{ hours}}{8 \text{ hours}}$$
$$TWA \approx 0.11 \text{ mg/m}^3$$ (#page=35, 36) [35](#page=35) [36](#page=36).
**Example 2:** A chemical has a TWA exposure limit of 50 ppb for an 8-hour workday. An employee's exposure is measured at 40 ppb for 2 hours, 60 ppb for 4 hours, and 30 ppb for 2 hours. Calculate the TWA.
$$TWA = \frac{(40 \text{ ppb} \times 2 \text{ hours}) + (60 \text{ ppb} \times 4 \text{ hours}) + (30 \text{ ppb} \times 2 \text{ hours})}{8 \text{ hours}}$$
$$TWA = \frac{80 + 240 + 60}{8} \text{ ppb}$$
$$TWA = \frac{380}{8} \text{ ppb} = 47.5 \text{ ppb}$$
Since 47.5 ppb is less than the PEL of 50 ppb, the exposure does not exceed the limit [37](#page=37).
**Example 3:** Welders are exposed to welding fumes at an average concentration of 5 mg/m³ for 5 hours per day. The PEL is 5 mg/m³ for an 8-hour day. Calculate the welders' 8-hour welding fume exposure.
$$TWA = \frac{5 \text{ mg/m}^3 \times 5 \text{ hours}}{8 \text{ hours}}$$
$$TWA = \frac{25}{8} \text{ mg/m}^3 = 3.125 \text{ mg/m}^3$$
The 8-hour TWA exposure is 3.125 mg/m³. Since this is less than the PEL of 5 mg/m³, the exposure does not exceed the limit [38](#page=38).
**Example 4:** A painter is exposed to toluene. Task 1: 80 ppm for 2 hours. Task 2: 50 ppm for 3 hours. Task 3: 20 ppm for 1 hour. The 8-hour PEL for toluene is 100 ppm. Calculate the painter’s 8-hour TWA exposure.
$$TWA = \frac{(80 \text{ ppm} \times 2 \text{ hours}) + (50 \text{ ppm} \times 3 \text{ hours}) + (20 \text{ ppm} \times 1 \text{ hour})}{8 \text{ hours}}$$
$$TWA = \frac{160 + 150 + 20}{8} \text{ ppm}$$
$$TWA = \frac{330}{8} \text{ ppm} = 41.25 \text{ ppm}$$
Since 41.25 ppm is less than the PEL of 100 ppm, the exposure does not exceed the limit [39](#page=39).
**Example 5:** A worker is exposed to xylene at different concentrations. Task 1: 120 ppm for 45 minutes. Task 2: 80 ppm for 90 minutes. Task 3: 20 ppm for 60 minutes. No exposure for the remaining time. Calculate the 8-hour TWA exposure.
Convert durations to hours:
Task 1: 45 minutes / 60 minutes/hour = 0.75 hours
Task 2: 90 minutes / 60 minutes/hour = 1.5 hours
Task 3: 60 minutes / 60 minutes/hour = 1.0 hour
Total work time = 0.75 + 1.5 + 1.0 = 3.25 hours.
$$TWA = \frac{(120 \text{ ppm} \times 0.75 \text{ hours}) + (80 \text{ ppm} \times 1.5 \text{ hours}) + (20 \text{ ppm} \times 1.0 \text{ hour})}{8 \text{ hours}}$$
$$TWA = \frac{90 + 120 + 20}{8} \text{ ppm}$$
$$TWA = \frac{230}{8} \text{ ppm} = 28.75 \text{ ppm}$$ [40](#page=40).
**Example 6:** A construction worker is exposed to wood dust during an 8-hour shift.
Task | Dust Concentration (mg/m³) | Duration (minutes)
------- | -------- | --------
High-dust cutting | 6 | 30
Moderate sanding | 3 | 120
Light finishing | 1 | 60
The PEL (8-hour TWA) for wood dust is 5 mg/m³.
a. Calculate the worker’s 8-hour TWA exposure to dust.
Convert durations to hours:
High-dust cutting: 30 minutes / 60 minutes/hour = 0.5 hours
Moderate sanding: 120 minutes / 60 minutes/hour = 2.0 hours
Light finishing: 60 minutes / 60 minutes/hour = 1.0 hour
Total work time = 0.5 + 2.0 + 1.0 = 3.5 hours.
$$TWA = \frac{(6 \text{ mg/m}^3 \times 0.5 \text{ hours}) + (3 \text{ mg/m}^3 \times 2.0 \text{ hours}) + (1 \text{ mg/m}^3 \times 1.0 \text{ hour})}{8 \text{ hours}}$$
$$TWA = \frac{3 + 6 + 1}{8} \text{ mg/m}^3$$
$$TWA = \frac{10}{8} \text{ mg/m}^3 = 1.25 \text{ mg/m}^3$$
b. Determine whether the exposure exceeds the PEL.
The calculated TWA exposure is 1.25 mg/m³, which is less than the PEL of 5 mg/m³. Therefore, the exposure does not exceed the PEL [41](#page=41).
c. Suggest two practical control measures to reduce dust exposure.
* **Engineering Controls:** Implement local exhaust ventilation systems at dust-generating points (e.g., cutting, sanding) to capture dust at the source.
* **Administrative Controls:** Limit the time workers spend in high-dust areas or rotate tasks to reduce individual exposure duration.
* **Personal Protective Equipment (PPE):** Provide and ensure the correct use of appropriate respirators.
* **Work Practices:** Wet methods can be used to suppress dust during cutting and sanding operations [41](#page=41).
### 3.4 Limitations of TLVs
While TLVs are valuable tools, they have certain limitations that must be considered [42](#page=42):
* **Limited database:** The database supporting TLVs may be limited for some substances [42](#page=42).
* **Individual differences:** TLVs do not account for individual variations in susceptibility due to genetic factors, age, personal lifestyle, or medical conditions [42](#page=42).
* **Measurement difficulties:** Accurately measuring existing exposures and obtaining representative breathing zone samples can be challenging [42](#page=42).
* **Uncertainty in inhalation:** There can be uncertainties regarding the actual quantity of a substance inhaled by a worker [42](#page=42).
---
## Common mistakes to avoid
- Review all topics thoroughly before exams
- Pay attention to formulas and key definitions
- Practice with examples provided in each section
- Don't memorize without understanding the underlying concepts
Glossary
| Term | Definition |
|------|------------|
| Hazard | A source or situation with the potential to cause harm in terms of human injury, ill health, damage to property, or damage to the environment. |
| Danger | The relative exposure to a hazard, indicating an unsafe situation created by a hazard. |
| Risk | A combination of the likelihood of an occurrence of a hazardous event and the severity of the resulting injury or damage to health, property, or the environment. |
| Imminent Danger | Defined as a serious risk of death or serious bodily injury to any person caused by any plant, substance, thing, or circumstance in the workplace. |
| Inhalation | The process of breathing in a hazardous substance, which can occur through the respiratory system. |
| Ingestion | The process of swallowing a hazardous substance, typically through contaminated food, drink, or hands. |
| Dermal Contact | Exposure to a hazardous substance through the skin, either by absorption or direct entry through cuts and wounds. |
| Occupational Health | The promotion and maintenance of the highest degree of physical, mental, and social well-being of workers in all occupations by preventing departures from health, controlling risks, and adapting work to people and people to their jobs. |
| Health Promotion | Activities aimed at improving and maintaining workers' optimum physical, mental, and social levels, encouraging healthy lifestyles. |
| Specific Protection | Measures taken to prevent specific illnesses or diseases arising from the workplace or work processes, such as using personal protective equipment or immunisation. |
| Early Detection of Hazards, Disease and Provision of Early Treatment | Activities focused on identifying hazards and diseases at an early stage and providing prompt medical intervention. |
| Limited Disability Rehabilitation | Measures to help individuals with disabilities regain function and return to work, including assessment, therapy, and compensation. |
| Occupational Medicine | A branch of medicine concerned with the health of workers, focusing on the prevention and treatment of occupational diseases and injuries. |
| Industrial Hygiene | The science and art devoted to the anticipation, recognition, evaluation, and control of those environmental factors or stresses, arising in the workplace, which may cause sickness, impaired health and well-being, or significant discomfort among workers or among the citizens of the community. |
| Occupational Toxicology | The study of the adverse effects of chemical, physical, or biological agents encountered during work on human health. |
| Ergonomics | The study of people's efficiency in their working environment, focusing on designing workplaces and systems to fit human capabilities and limitations. |
| Epidemiology | The study of the distribution and determinants of health-related states or events in specified populations, and the application of this study to the control of health problems. |
| Industrial Psychology | A branch of psychology concerned with the application of psychological principles to the problems of business and industry, particularly in the workplace. |
| Primary Prevention | Measures aimed at preventing hazards and diseases from occurring in the first place, including health promotion and specific protection. |
| Secondary Prevention | Activities focused on early detection of hazards and diseases, and providing early treatment to minimize their impact. |
| Tertiary Prevention | Interventions aimed at limiting disability and promoting rehabilitation after a disease or injury has occurred. |
| Medical Surveillance | A program of regular health check-ups and monitoring for workers exposed to specific hazards to detect early signs of health effects. |
| Hazard Control | Measures taken to eliminate or reduce exposure to workplace hazards, including engineering controls, administrative controls, and personal protective equipment. |
| Threshold Limit Value (TLV) | A guideline for exposure to a chemical substance that a worker can be exposed to, day after day, without adverse health effects. |
| Permissible Exposure Limit (PEL) | Legal limits established by regulatory bodies for the maximum allowable concentration of a substance in the workplace air. |
| TLV-TWA (Threshold Limit Value Time Weighted Average) | The average concentration of a substance in the air over an eight-hour workday to which workers can be exposed without adverse health effects. |
| TLV-STEL (Threshold Limit Value- Short Term Exposure Limit) | The maximum concentration to which workers can be exposed for a short period without suffering irritation, chronic damage, or narcosis. |
| TLV-C (Threshold Limit Value- Ceiling) | The highest concentration of a substance that should not be exceeded at any time during the workday. |
| Carcinogenic | Capable of causing cancer. |
| Noise Exposure | Exposure to sound levels that can cause hearing damage or other adverse health effects. |
| $85 \text{ dB(A)}$ | Decibels measured on the A-weighted scale, often used for noise exposure limits, with 85 dB(A) being a common 8-hour time-weighted average limit. |
| $115 \text{ dB(A)}$ | A maximum noise level limit, beyond which immediate hearing protection is crucial. |
| $140 \text{ dB(C)}$ | Decibels measured on the C-weighted scale, used for peak impulse noise, with 140 dB(C) representing a high-level, short-duration sound. |
| TWA (Time Weighted Average) | The average concentration of a substance in the air over a specified period, typically an eight-hour workday. |
| STEL (Short Term Exposure Limit) | The time-weighted average concentration of a substance over a short period, usually 15 minutes, thought not to be injurious to health. |
| Ceiling Limit (C) | A concentration in the air that should never be exceeded at any time throughout the duration of work. |
| PEL (Permissible Exposure Limit) | Legal limits used to measure exposure to airborne contaminants in the workplace. |
| "8-hour reference period" | Refers to the practice of equating occupational exposures within a 24-hour period to a single uniform exposure over eight hours for calculation purposes. |
| ppb | Parts per billion, a unit of concentration used for gases and vapors. |
| ppm | Parts per million, a unit of concentration used for gases and vapors. |
| mg/m³ | Milligrams per cubic meter, a unit of concentration used for particulate matter and dusts. |
| Carcinogenic Chemicals | Substances known or suspected to cause cancer, which often do not have established TWA/STEL/C limits due to their hazardous nature. |
| OSHA 1994 | Occupational Safety and Health Act 1994, a key piece of legislation governing workplace safety and health in Malaysia. |
| USECHH 2000 | Occupational Safety and Health (Use and Standards of Exposure of Chemicals Hazardous to Health) Regulations 2000, which outlines requirements for managing chemical hazards. |
| Noise Exposure 2019 | Occupational Safety and Health (Noise Exposure) Regulations 2019, which sets out specific limits and requirements for noise control in the workplace. |
| JKKP (DOSH) | Department of Occupational Safety and Health (Malaysia), responsible for legislation, standards, enforcement, and promotion of occupational safety and health. |
| NIOSH | National Institute for Occupational Safety and Health (Malaysia), involved in training, consultation, research, and information dissemination. |
| PERKESO (SOCSO) | Social Security Organization (Malaysia), responsible for compensation and promotion of social security benefits for workers, including work-related injuries. |
| HSE | Health and Safety Executive (UK), the national regulator for workplace health and safety in the United Kingdom. |
| ACGIH | American Conference of Governmental Industrial Hygienists, an organization that develops and publishes Threshold Limit Values (TLVs). |
| ILO | International Labour Organization, a United Nations agency promoting social justice and internationally recognized human and labour rights. |
| IARC | International Agency for Research into Cancer, part of the World Health Organization, classifying carcinogens. |
| TLV Limitations | Restrictions or drawbacks associated with the use of Threshold Limit Values, such as individual variability and measurement difficulties. |