ABNT NBR 16385 Prevention and Protection of Dust Explosion Systems - Production, Processing and Handling of Combustible Particulate Solids - Requirements

The standard “ABNT NBR 16385 Prevention and protection of dust explosion systems - Production, processing and handling of flammable particulate solids - Requirements”, developed by the Brazilian Association of Technical Standards (ABNT), describes the requirements for all surfaces of the manufacture, processing, blending, transportation, repackaging and handling of flammable particulate solids or hybrid mixtures, regardless of the concentration or particle size that may pose an explosion hazard.

This standard does not apply to the following materials or systems which require reference to specific documents:

• Dynamite, black powder, TNT and similar explosive materials
• Pyrotechnic materials or pyrotechnic factories
• Flammable solids for rockets
• Solid sulfur
• Boilers and steam generators
• Coal mines
• Nuclear field

Dust explosions occur when flammable dust accumulates in the air and burns rapidly, creating a powerful pressure wave. They are a deadly hazard in a variety of workplaces, from grain silos to plastics factories. A dust explosion requires several factors to be present simultaneously. These include: flammable dust at the right concentration, oxygen, a confined space, and an ignition source.

If the dust concentration is too low, there is not enough dust to fuel an explosion. If the concentration is too high, there is not enough oxygen to support combustion. While some combustible dusts are easy to identify (such as wood and paper dust), others, such as aluminum dust, are not. Combustible dusts become more hazardous as the particles become finer. These dusts have a high surface area to volume ratio, which increases their flammability. When these dusts combine with oxygen within a certain concentration range, a dust explosion is possible.

Under these conditions, all that is needed for an explosion is an ignition source. This could be anything from a cigarette to a spark or an overheated wheel bearing. Under the right conditions, some combustible dusts can self-ignite due to the static that builds up as the particles rub together. Ignition causes the dust to burn rapidly. Sometimes this explosion can stir up dust that has accumulated in the area, creating a new dust cloud that is the fuel source for a massive secondary explosion. A dust explosion can blow out walls in a facility and kill or injure workers in the area or nearby.

For the purposes of this standard, in addition to the terms and definitions explained in ABNT NBR ISO 6184-1, ABNT NBR ISO 6184-3 and ABNT NBR ISO 6184-4 and ABNT NBR 15662, the following terms and definitions apply:

• Water compatibility refers to a substance that does not react with water or is incompatible with water and therefore can be extinguished by a water-based extinguishing system.
• Incompatibility with water refers to a substance that does not react chemically with water but undergoes a phase change or change in physical state when mixed with water, causing a permanent change that is incompatible with the rest of the process.
• Reduced pressure refers to the maximum pressure in a system during the alleviation of a flare.
• Static pressure refers to the opening pressure of the release panel designed to open in the event of an explosion.
• Maximum burst pressure refers to the maximum pressure that occurs when an explosion occurs.
• The explosion hazard area is the volume of the building or room in which the extinguishing of the accumulated or accumulated dust mass can cause a pressure greater than the strength of the weakest structural element and is bound to fail.
• The fire hazard area at the time of explosion refers to the area where the accumulation of combustible dust on open or concealed surfaces outside equipment or containers could cause bodily injury due to thermal radiation doses during ignition, as well as all areas where a concentrated dust cloud exists and would result in a dangerous flash or fire hazard.
• Minimum detonation concentration refers to the minimum concentration of fuel suspension in air, measured as mass per unit volume, that will support a deflagration.
• Medium volume flexible containers refer to flexible containers made of non-conductive, recyclable, high-resistance polypropylene fabric, subjected to anti-UV (ultraviolet rays) treatment, sewn with internal polyethylene liners, containing four seams fixed in their vertical seams or on their sides.

This standard is applicable to all stages of production, processing, mixing, pneumatic conveying, storage, packaging and transportation of flammable solid particles or hybrid mixtures, regardless of concentration and particle size, when the substances present a fire or explosion hazard.

This standard provides a foundation for all industries in the sector and helps reinforce the necessity and importance of investing in process safety. Developed for both industrial and commercial projects and existing facilities, explosion prevention and protection systems are committed to the handling, processing, transportation and storage of flammable solid particles in accordance with the following principles:

• Preventing the formation of explosive atmospheres
• Avoiding the presence of ignition sources
• Protection to limit the effects of an explosion

Among the numerous tests, measurements, analyses and evaluation studies carried out for businesses in various sectors, our organization also provides testing services defined in the “ABNT NBR 16385 Prevention and protection of dust explosion systems - Production, processing and handling of flammable particulate solids - Requirements” standard with its trained and expert staff and advanced technological equipment.