The Importance of Knowing Hazardous Classification Chart in Hazardous Location Work

When we go to work each day, we expect to do our job and come home in one piece. Unfortunately, 3.4 workers out of 100,000 will end up as a sad statistic due to a workplace tragedy. What kind of hazards are there in your workplace? There are two general risks to workers, handling hazardous chemicals and materials and hazardous locations. 

The Occupational Safety and Health Administration (OSHA) and Canadian Electrical Code (CEC) work tirelessly to bring that statistic down to zero. One of the methods these organizations implemented is the identification and classification of hazardous locations. 

The hazardous classification chart serves as a guide to identify and classify different hazardous materials and their associated risks. Workers should familiarize themselves with this chart to assess their work environment’s potential dangers and take necessary precautions to ensure their safety. 

What Are Hazard Classifications?

Hazard classifications are a systematic way of categorizing and identifying the potential hazards associated with a substance, product, or location. Workers use these classifications as a reference to communicate the health, physical, and environmental hazards that may be present. 

There are two primary hazards in the workplace, chemicals and locations. OSHA has a system to classify chemicals and substances listed in the OSHA Hazard Communication Standard (HCS) (Subpart Z, Toxic and Hazardous Substances, 29 CFR 1910.1200). The two main classifications for each chemical are health hazards, like Acute toxicity and Carcinogenicity, and physical hazards, like Explosives or Oxidizing gases.

Hazardous classified locations fall into zones or divisions based on the likelihood and duration of hazardous substance presence or risk of physical injury due to equipment or other danger. These zones or divisions guide the level of safety measures and equipment needed.

Compliance begins with understanding the specific hazard class. A hazardous classification chart makes visualizing and understanding the various hazards easy. 

Types of Hazardous Location Classifications: 

A hazardous classifications chart has three classes of hazardous locations based on the nature and level of potential risks present:

  1. Class I locations are those with the greatest potential for ignition. They include areas where flammable gases or vapors are present in concentrations above the lower explosive limit (LEL). Ignition sources in these areas can include sparks, flames, and heaters.
  2. Class II locations have a less severe potential for ignition than Class I but still pose a risk. They include areas where combustible dust is present in concentrations above the LEL. Ignition sources in these areas can include sparks, flames, and heaters.
  3. Class III locations have the lowest potential for ignition and include wet locations with a risk of electric shock.

Hazard classifications aim to assess the potential risks associated with different substances. By categorizing areas into specific hazard zones, it becomes easier to implement appropriate safety measures and equipment to mitigate risks and protect workers. Safety measures include proper ventilation, PPE, electrical equipment ratings, and explosion-proof or intrinsically safe equipment.

Where Can You Find Hazardous Location Definitions?

Hazard classifications identify and categorize areas with a potential risk. There is an alphabet soup of national and international agencies that classify workplace environmental hazards. They include:

Determining Classification Designation for A Facility Or Plant Site

The most important factor is the nature of the products or materials processed or stored on-site. Other factors include the presence of flammable liquids, combustible materials, and sparks or flames. Determining the proper classification designation includes:

  1. Nature of the Substances Present: The primary hazardous substances are flammable gases, liquids, vapors, and combustible dusts.
  2. Quantity and Concentration: Higher quantities or concentrations of flammable substances require stricter safety measures and equipment to mitigate the risks.
  3. Frequency and Duration of Presence: Some areas may have an intermittent or occasional presence, while others may have continuous or prolonged exposure. 
  4. Ventilation and Airflow: Proper ventilation systems can help control the dispersion of flammable substances and minimize the risk of ignition. 
  5. Ignition Sources: Ignition sources can include electrical equipment, open flames, sparks, or hot surfaces. One way to mitigate this condition is with hazardous area drum and tote heaters.
  6. Containment and Control Measures: Adequate spill containment systems, leak detection, and fire suppression systems can mitigate the risks associated with hazardous substances.
  7. Regulatory Requirements: Regulatory compliance can determine the classification designation. Different regions or countries have specific regulations and standards that dictate the classification criteria for facility or plant sites.

Classification designations vary based on the specific industry sector, such as oil and gas, chemical manufacturing, or pharmaceuticals. Consulting with experts and conducting thorough risk assessments can help ensure accurate classification designation. 

Explanation of the Hazardous Classification Chart

The hazardous classification chart breaks down the three classes into zones and divisions to further categorize hazardous locations.

Zones: Zones represent the likelihood and duration of hazardous substances. The zones are as follows:

  1. Zone 0: Areas where hazardous substances are in high concentrations for extended periods.
  2. Zone 1: Hazardous substances are present under normal operating conditions.
  3. Zone 2: Indicates locations where hazardous substances are unlikely to be present under normal operating conditions but may occur intermittently.

Divisions: Divisions represent the likelihood of hazardous substance ignition and the level of protection required.

  1. Division 1: Areas with a high probability of hazardous substance ignition due to abnormal conditions or equipment failure.
  2. Division 2: Areas with a low probability of igniting a hazardous substance. It is limited to abnormal conditions or equipment failure.

Consulting the chart and adhering to its guidelines minimizes the risk of accidents, protects lives, and ensure a safe working environment.

How to Use The Hazardous Classification Chart

The hazardous classification chart requires a systematic approach to assess the risks and determine the appropriate safety measures. 

  1. Identify the hazardous substances: Consult material safety data sheets (MSDS) or other relevant documentation to determine the nature and properties of these substances.
  2. Determine the classification: Refer to the hazardous classification chart and identify the appropriate class, division, and group for the hazardous substances present. 
  3. Assess the risks: Risk assessment, such as the likelihood of release, the concentration of the substances, and the potential ignition sources, will help determine the appropriate safety measures.
  4. Select equipment and implement safety measures: Safe equipment means explosion-proof or intrinsically safe, properly rated electrical enclosures, custom hazardous location heaters, and appropriate ventilation systems. 
  5. Regularly review and update: Hazardous environments can change over time. Review the hazardous classification chart and reassess the risks regularly. Stay updated with any safety regulations or standards changes to ensure continued compliance and safety.

By following this systematic approach and utilizing the hazardous classification chart, you can make informed decisions and implement effective safety measures in hazardous locations.

Importance of Taking Proactive Measures for Accident Prevention

Proactive accident prevention is critical in maintaining a safe and healthy workplace. Here are some key reasons being diligent pays off:

  1. Employee Safety: Proactive measures identify and address potential hazards before accidents occur, significantly reducing the risk of injuries and reportable incidents.
  2. Cost Savings: Preventing accidents helps reduce medical, legal, and other costs associated with workplace injuries. 
  3. Improved Productivity: Employees who feel safe and secure in their work environment are more productive and focused. Accident prevention creates a positive work atmosphere, fostering employee morale and motivation.
  4. Compliance with Regulations: By ensuring compliance with local, state, and federal regulations that meet or exceed safety standards, companies can avoid penalties, fines, and legal repercussions.
  5. Reputation and Employee Retention: A company that prioritizes safety builds a positive reputation among its employees and industry peers. It helps attract and retain top talent.

A good example of being proactive is with winterization safety measures. The U.S. Chemical Safety and Hazard Investigation Board has a video showing how the lack of planning related to winterization can lead to deadly incidents. Hazardous location freeze protection prevents catastrophic failures.

By consistently implementing proactive measures for accident prevention, companies can create a safety culture, protect their employees, and contribute to a more productive and successful workplace.

Ensuring Your Facility or Plant Site Compliance with Hazardous Location Classifications

By understanding and adhering to the appropriate hazard classification for your facility, you can implement necessary safety practices to reduce accidents or incidents. Regular assessments and compliance checks should be standard operating procedures for every business to maintain a safe working environment and ensure compliance.

Consequences of Non-Compliance with Hazardous Location Classifications Regulations

The National Safety Council estimates that each prevented lost-time injury or illness saves an employer an average of $37,000. However, 2021 statistics revealed 62 million job-related injuries resulting in over $1.2 billion in losses.

Costs to the employer for an accident include workers’ compensation payments, medical expenses, non-compliance fines, litigation expenses, property losses, increased insurance costs, and indirect costs. Moreover, non-compliance can lead to production disruptions, project delays, and potential damage to equipment or facilities. 

Typical Oversights in Compliance and Safety Practices 

While the hazardous classification chart is a valuable tool, there are common mistakes that managers should be aware of to ensure accurate interpretation and implementation of safety measures. Here are some common mistakes:

  1. Misclassifying hazardous substances or locations can lead to inappropriate safety measures and risks to workers and the environment.
  2. Failing to reassess hazardous classification regularly results in outdated safety practices that do not adequately address risks.
  3. Neglecting non-electrical hazards in hazardous locations, such as chemical exposure or physical hazards from equipment.
  4. Lack of proper documentation leads to confusion, inadequate training, and compromised safety. Keep accurate records for clear communication and decision-making.

By identifying these common mistakes, professionals can accurately interpret the hazardous classification chart and implement effective safety measures in hazardous locations.

Ways to Avoid These Mistakes

Here are a few ways to avoid these mistakes:

  1. Comprehensive Training: Conduct thorough training on safety protocols, procedures, and best practices. Ensure that they have a clear understanding of potential hazards and the correct methods to mitigate them.
  2. Regular Inspections: Conduct routine workplace inspections to identify potential hazards or safety risks. Regular inspections help identify and address issues before accidents or injuries occur.
  3. Effective Communication: Establish clear lines of communication between management, supervisors, and employees. Encourage open dialogue and the reporting of any safety concerns or near-miss incidents. Promptly address these concerns to prevent future accidents.
  4. Personal Protective Equipment (PPE): Make PPE mandatory and train all employees how to use personal protective equipment properly. Regularly inspect and replace worn-out or damaged equipment to maintain its effectiveness.
  5. Hazard Assessments: Conduct regular hazard assessments to identify and evaluate potential risks in the workplace. This assessment should comprehensively analyze machinery, equipment, work processes, and employee behaviors.

It is critical to consider and address non-electrical and electrical hazards to ensure everyone’s safety. Documentation is crucial in maintaining compliance and ensuring effective communication of safety protocols.

Resources for Understanding and Complying with Hazardous Location Classifications: 

You can use various business and governmental resources to better understand and comply with hazardous classifications. Here is a short list to help you:

  1. Occupational Safety and Health Administration (OSHA) – Workplace Safety Awareness Council Hazardous Location flier
  2. National Fire Protection Association (NFPA) developed the National Electrical Code (NEC). NEC Code 500 defines hazardous locations. This video explains in more detail.
  3. Grainger Hazardous Location Charts – This page lists NFPA 70 NEC Hazardous Locations Classes, Divisions, and Groups, NFPA 70 NEC Hazardous Locations Zones, and NFPA 70 NEC Hazardous Locations Groups.
  4. A Guide to Hazardous Location Classifications by the Kenall company 
  5. The NFPA 70® National Electrical Code has been updated for 2023 and is valid for all 50 states.
  6. Consulting Services – These experts can assess the workplace environment, identify potential hazards, and provide recommendations to ensure compliance with the appropriate classifications.
  7. Manufacturer Documentation – Equipment manufacturers, such as hazloc heaters, provide detailed documentation, including datasheets, user manuals, and installation guides. These documents often contain valuable information regarding the equipment’s suitability for specific hazardous location classifications.

Organizations can use these resources to enhance their understanding of hazardous location classifications and stay safe.

The Importance of Hazard Classification in Ensuring Workplace Safety

A hazardous classification chart is vital in understanding the risks in various workplace environments. It provides essential information about the properties and risks associated with hazardous materials, enabling workers to make informed decisions and take appropriate precautions. By understanding and utilizing the chart, workers can correctly identify and classify hazardous materials, prevent accidents and injuries, and ensure compliance with safety regulations.

To keep your equipment running smoothly and prevent damage in hazardous locations, explore Powerblanket’s advanced hazardous location heating systems. These systems provide safe and efficient heating solutions, ensuring optimal performance while minimizing the risks associated with hazardous materials.

Keep your equipment running smoothly and prevent damage with Powerblanket's advanced hazardous location heating systems.


Alex Pacanowsky

Meet Alex, one of our experts in freeze protection and the head of the custom team at Powerblanket! For the past several years, Alex has worked closely with oil & gas pros, medical device startups, and pharmaceutical suppliers (just to name a few) to create weatherproof operations. No matter how cold the weather, or what needs to be heated, Alex knows just what to do! He also loves mountain biking and spending time with his two boys, 5 and 9, and two Labrador Retrievers.

Leave a Reply

Your email address will not be published. Required fields are marked *