HazLoc Classification Guide

There are multiple organizations and governing bodies that provide classifications for hazardous locations. An overview and comparison of the National Electric Code (NEC) published by the National Fire Protection Association (NFPA) in the United States - defines classes, divisions, and groups, while the International Electrotechnical Commission (IEC) defines zones and groups for equipment in hazardous locations.

There are many types and combinations of precautions to keep people safe in hazardous environments. The following are a few examples of general precautions associated with different NEC classes, divisions, and groups. Precautions include:

Class I: areas with flammable gases or vapors.

• Grounding and bonding: electrical equipment and conductive materials should be properly grounded and bonded to prevent static electricity buildup and sparks.
• Explosion proof enclosures: enclosures designed to withstand and contain internal explosions.
• Intrinsically safe equipment: Low-energy devices used to minimize sparking or heat generation.

Class II: areas where combustible dust is present. 

• Regular cleaning and housekeeping: frequent cleaning to minimize the accumulation of combustible dust.
• Dust collection systems: systems to capture and remove dust particles from the air, preventing buildup on equipment and surfaces.
• Spark-resistant tools: tools made from materials that reduce sparks.

Class III: areas with ignitable fibers or flyings, like cotton or sawdust.

• Regular maintenance and inspection: routine checks to identify and repair potential ignition sources.
• Proper storage and handling: ignitable fibers or flyings should be stored in designated containers and procedures implemented to prevent accumulation and contact with ignition sources.
• Use of flame-resistant clothing: workers may need to wear flame-resistant clothing to minimize fire spread in the case of accidental ignition.

Divisions categorize hazardous areas based on the likelihood and duration of the presence of hazardous substances. Precautions include:

Division I: environments where hazardous materials are regularly present. 

• Strict access control: restricted access to authorized personnel only with measures such as locked doors, security protocols, and proper training.
• Continuous monitoring: gas detectors, dust monitoring systems, and automated alarms provide real-time information about potential hazards, allowing immediate response and evacuation.
• Specialized ventilation: specialized ventilation systems to maintain safe conditions, like explosion-proof fans, ductwork, and airflow controls.

Division II: environments where hazardous materials are present only under abnormal conditions.

• Equipment inspection and maintenance to identify and repair potential ignition sources.
• Regular cleaning to minimize the accumulation of combustible dust and buildup on surfaces.
• Emergency response planning: outline specific procedures for dealing with abnormal conditions, including leakages, failures, or other incidents. Adequate training, communication systems, and evacuation routes are essential.

National Electrical Code (NEC): The National Electrical Code (NEC) is a widely recognized standard primarily used in the United States for electrical installations in hazardous locations. It provides guidelines and requirements for the creation of HazLoc classes, groups, and divisions, ensuring the safe operation of electrical equipment in these environments. One notable difference between NEC is its specific focus on electrical installations and its comprehensive coverage of various hazardous area classifications.

International Electrotechnical Commission (IEC): The International Electrotechnical Commission (IEC) is a global organization that sets international standards for electrical equipment used in hazardous areas. The IECEx certification, issued by the IEC, ensures that equipment meets the international safety requirements for HazLoc classes, groups, and divisions. One notable difference of IEC is its global reach and recognition, making it applicable to HazLoc classifications worldwide.

Canadian Standards Association (CSA): The Canadian Standards Association (CSA) is responsible for issuing hazardous location certifications in Canada, which are equivalent to those provided by NEC and IECEx. CSA standards play a significant role in defining HazLoc classes, groups, and divisions within the Canadian context. One notable difference of CSA is its specific focus on Canadian regulations and requirements, ensuring compliance with national safety standards.

European ATEX Directive: The European ATEX (Atmosphères Explosibles) Directive sets requirements for equipment and protective systems intended for use in hazardous areas within the European Union. It provides guidelines for the classification of HazLoc classes, groups, and divisions, ensuring the safety of equipment used in potentially explosive atmospheres. One notable difference of the ATEX Directive is its comprehensive coverage of both electrical and non-electrical equipment, addressing a wide range of hazards.

Equipment and Protective Systems Intended for Use in Potentially Explosive Atmospheres Regulations 2016 (UKEX Regulations): UKEX regulations that have previously conformed with the European ATEX Directive have been amended due to the departure with the European Union. While both ATEX and UKEX will likely continue to have similar requirements, certification applications will need to be submitted to both regulating bodies.

Occupational Safety and Health Administration (OSHA): OSHA is a regulatory body in the United States that sets and enforces safety standards for workplaces, including hazardous locations. While not specifically focused on HazLoc classes, groups, and divisions, OSHA regulations incorporate general safety requirements that apply to these environments, ensuring the protection of workers and the prevention of accidents and incidents. One notable difference of OSHA is its broader scope, encompassing safety regulations for various industries and workplace settings beyond hazardous locations.