Understanding Standards for Chemical Protective Suits

Issue 12 and Volume 17.

Ian Hutcheson

Preparedness is the watchword for any professional who puts his or her life on the line to deal with chemical spills, accidents, or other dangerous situations. Although training is important, when a hazmat suit is the only thing standing between a first responder and harmful chemicals or gases, the performance of the protective suit is absolutely vital. Past chemical industrial disasters and incidents have served as real-life lessons helping to demonstrate the needs, risks, and challenges facing emergency response teams, driving safety and performance standards as well as innovation in the protective fabric industry.

Depending on where they are sold, chemical protective suits must comply with specific regional standards, ensuring that they meet stringent performance requirements. For example, in Europe, EN compliance is required, while in the United States and Canada, the National Fire Protection Association (NFPA) is the primary compliance standard for protective suits and equipment. To meet these standards, protective suits and equipment are exposed to harsh conditions, simulating the actual threats responders might face in the field, such as extreme temperatures, chemical exposure, and abrasion.

Although both EN and NFPA standards provide a guaranteed level of safety and performance, it is important to note that they are not the same. Each requires different testing procedures, each with its own methodology to simulate real-life hazmat incidents. To ensure that they procure the best equipment for their emergency response teams, it is essential that organizations and companies understand the two main international standards for hazmat suits, EN 943 and NFPA 1991, Standard on Vapor-Protective Ensembles for Hazardous Materials Emergencies, as well as the differences between them, including the tests performed and minimum performance requirements.

Compliance Overview

Throughout Europe, compliance standards are defined and maintained by the European Committee for Standardization (CEN). The EN 943 standard covers protective clothing against liquid and gaseous chemicals, including liquid aerosols and solid particles, with a specific section, EN 943-2, dealing with chemical protective suits for emergency responders and firefighters.

The leading advocate for fire prevention and public safety in the United States and Canada is the NFPA. The NFPA has developed codes and standards, such as NFPA 1991, aimed at minimizing the occurrence and effects of fire and other hazardous threats. The highest level of compliance available in North America, NFPA 1991 specifies the minimum design, manufacture, and performance requirements for vapor-protective ensembles and individual elements for chemical vapor protection. NFPA 1991 sets standards for chemical permeation, vapor tightness, flame resistance, and material durability. In addition, NFPA 1991 includes optional criteria for chemical flash fire escape and liquefied gas protection. However, NFPA 1991 is not the only benchmark for personal protective equipment (PPE) available.

The differences between European and North American standards begin with the various PPE classifications. In the United States, for example, hazmat protective clothing is classified by the Occupational Safety and Health Administration (OSHA) as Level A, B, C, or D based on the degree of protection provided. Level A, the highest level of protection against vapors, gases, mists, and particles, applies to fully encapsulating chemical entry suits with a built-in breathing apparatus. Meanwhile, under the European Union Council Directive 9/686/EEC on PPE, protective clothing is divided into six classes. Type 6 is the most basic level of protective clothing for dust and dirt nuisances, while Type 1 refers to fully encapsulating protective clothing. In addition, current European directives require that all PPE have the European Conformity (CE) approval and label, regardless of type and category. There is no such requirement for approved equipment in North America.

Testing Differences

Emergency responders and industrial employees throughout the world prepare for similar real-life situations and, as a result, many of the tests performed under EN 943 and NFPA 1991 are similar, including those for gas-tight integrity, flame resistance, and chemical permeation against many of the same toxic chemicals and gases. These tests seek to simulate actual scenarios, such as emergency responses, fires, chemical spills, and terrorist incidents with release of poisonous gases or chemicals. However, when comparing the two certifications, it is also important to understand the different test methodologies and minimum performance requirements to ensure a suit provides the maximum protection for an intended application. Detailed comparison of the test requirements results in five key areas of performance evaluation.

(1) Saint-Gobain’s ONESuit® Pro is EN 943 and NFPA 1991 compliant. (Photos courtesy of Saint-Gobain Performance Plastics.)

Chemical Permeation Testing

For chemical permeation testing, both EN 943 and NFPA 1991 use the same test methodology. However, EN 943 has a less severe minimum permeation detection level of 1.0 mg/cm2/min vs. the NFPA 1991 level of 0.1mg/cm2/min. In addition, NFPA 1991 requires preconditioning prior to chemical permeation testing, while EN 943 testing does not. This means that NFPA 1991 compliant materials are subjected to the physical stresses of both flexing and abrasion of outer surface with course sandpaper repeatedly before actual permeation testing.

Gases and Chemical Warfare Agents

NFPA 1991 chemical testing covers a much broader spectrum of chemicals than EN 943. It covers all the chemicals listed in EN 943 except for heptane and additionally specifies only 1⁄10 chemical permeation detection level requirements. NFPA 1991 compliant suits are tested against 19 toxic industrial chemicals, six gases, and two warfare agents, while EN 943 only covers 12 toxic industrial chemicals and three gases and does not test at all for chemical warfare agents.

Pressure Testing

Gas-tight integrity-vital for any protective suit that may come into contact with toxic chemicals and gases-can only be determined by performing a pressure or inflation test and a leak detection test of the respective protective suit. This ensures not only that base suit material is gas-tight but also that all seams and joints are equally gas-tight. This test typically involves closing off suit exhalation valves and inflating the suit to a specified pressure to observe whether or not the suit holds that pressure for a designated period of time. Both tests involve preinflating the suit at an elevated pressure-one minute for NFPA or 10 minutes under the EN standard. More importantly though, EN 943 features an actual six-minute test period at 1,650 Pa (6.6 inches water pressure), while the NFPA 1991 test is only four minutes at 1,000 Pa (four inches water pressure). Both standards, however, are similar in not allowing any more than 20 percent loss of starting pressure during the test period, although actual results on suits in use should be well above these thresholds for maximum reliability.

Flame and Flash Resistance

EN 943 compliance does not include any test for flash fire resistance and requires very limited flame resistance (one second). NFPA 1991 compliance involves more rigorous flame and burn testing and has an optional test for flash fire resistance. Some suits that meet the requirements of EN943-2 do not meet the NFPA 1991 standard unless they are equipped with a second aluminized oversuit, which significantly reduces comfort and dexterity and increases weight and bulk.

Flash fire resistance is an optional requirement met by some suits. The test method includes putting the ensemble onto a mannequin in a sealed, propane-filled flash chamber. The suit is then subjected to a remotely ignited six- to eight-second burn and must exhibit airtight integrity, thermal insulation, and visual acuity following the exposure to meet minimum standards, all in addition to the requirement for no after flame.

Hand Protection

Protective suit accessories, such as visors, seams, and gloves, also need to be manufactured using highly protective textiles and materials. Both NFPA 1991 and EN 943-2 require gloves to meet a high level of chemical and permeation resistance. NFPA 1991 has set much higher standards for cut and puncture resistance, which require that an outer glove be worn in addition to the chemical barrier glove. In most cases, two barrier gloves (a film inner and elastomer outer glove), are worn to obtain the full range of chemical protection and breakthrough times.

(2) For superior chemical permeation and puncture resistance, look for a glove that is NFPA 1991 compliant.

Understand the Standards

Though unintentional, chemical industrial disasters and incidents happen, and unfortunately CBRN terrorist acts are a real and ongoing possibility. As a result, there is a wide variety of innovative protective suits and equipment on the market, meeting a range of safety and performance standards. To keep emergency responders and industrial employees safe in the event that PPE becomes necessary, it is critical to understand the various standards, testing, and performance requirements. These factors will help emergency service professionals and procurement groups determine which suit is most appropriate for their needs, ensuring that emergency response teams and employees are able to do their jobs as safely and effectively as possible.

EN 943 and NFPA 1991 are widely considered to be the global gold standards in PPE performance for gas- and liquid-tight chemical protective clothing. But personnel need to clearly understand the key differences. To ensure maximum protection that provides the highest level of safety for hazmat and emergency personnel, organizations and companies should specify suits that meet both EN 943 and NFPA 1991 requirements.

IAN HUTCHESON is market manager, protective and fabricated systems Europe, at Saint-Gobain Performance Plastics. He is responsible for strategy and business development across Europe, the Middle East, and Africa. Hutcheson has more than 25 years of experience in the field of engineered plastics and technical textiles. He has a bachelor’s degree in economics and business studies.