Tips For New Legislations in Dec. 2016
Latest Interpretation of the Safety Specification For Prevention of Dust Explosions From the Mechanical Processing of Aluminums and Magnesium Products (AQ 4272-2016)
Notes by EHS.CN
On January 18, 2016, the State Administration of Work Safety issued the draft version of the Safety Regulations for Dust Explosion Prevention and Protection (GB15577-2007) (please visit http://www.ehs.cn/article-19132-1.html for professional interpretation), which is the general standard for the industry. The Safety Specification For Prevention of Dust Explosions From the Mechanical Processing of Aluminums and Magnesium (AQ 4272-2016) coming into force on March 1, 2016, provides safety regulations of the prevention of dust explosions for particular industries. The followings are some interpretations.
Firstly, it is about the divisions of the dust explosive environment and examples
Notes by EHS.CN
The "three dangerous classes of Zone 20, 21 and 22" are methods of design and management for electric power equipment, which are introduced into the revision of GB15577 and AQ 4272-2016, dividing the dangerous environment of dust explosion and offering examples, clarifying which areas belong to dangerous areas of dust explosion, being more practical.
Secondly, it is about the explosion prevention of electrical installations.
AQ4272(征求意见稿)对铝镁粉尘环境爆炸危险场所内电气设备防爆类型提出了如下要求:(1)20区或21区内的电气设备应选用DIP A20或DIP A21、DIP B20或DIP B21型。(2)22区内的电气设备应选用DIP A21 (IP6X)、DIP B21型。(备注：DIP表示粉尘防爆)
AQ4272 (the consultation draft) proposes following requirements for the electrical installations in the explosive dangerous places with aluminum and magnesium powders: (1) electrical installations in Zone 20 or 21 shall choose DIP A20 or DIP A21, DIP B20 or DIP B21; (2) electrical installations in Zone 22 shall choose DIP A21 (IP6X), DIP B21. (Note: DIP represents dust ignition-proof)
The regulations specified in the issued version of AQ4272:
8.1 Electrical circuit and electrical equipment in the mechanical processing work places of aluminum and magnesium products shall meet the requirements of GB50168, GB50169, GB13955.
8.2～8.3 The choose and the type of electrical installations, controlling equipment, monitoring and warning equipment in the dangerous areas with dust explosions shall meet the requirements of GB12476.1 and GB12476.2, the electrical circuit shall meet the GB50058.
8.4 Antistatic devices shall meet GB12158, the earthen system shall meet GB50058.
8.5 After the installation, renewal and regular maintenance, electrical installations, controlling equipment, monitoring and warning equipment shall go through the insulation resistance detection.
8.6 There shall be no dust over the electrical circuit, electrical installations, controlling equipment, monitoring and warning equipment.
Notes by EHS.CN
In the consultation draft, it just simply proposed the requirements of installing the dust ignition-proof equipment. But the requirements 8.1～8.4 stated in the issued version meet relevant standards, which are more stringent. The cases of dust explosion caused by electrical equipment's ignition are not rare.
On June 19, 2016, aluminum dust explosion occurred in a motorcycle accessories company in Wenzhou, and the direct cause of the accident was that the dust removal facility used by the company did not meet standards and requirements, causing long-term accumulation of aluminum in the wall, forming a dust cloud, which met the sparks caused by electrical equipment failing to meet the requirements of ignition-proof, resulting in an explosion.
Requirements related to electrical equipment are professional, so EHS personnel shall apply their own knowledge or mobilize other available resources into the daily safety management and achieve zero omission.
Thirdly, it is about the safety management for the operation -- requirements are much more specific.
11.1 The operators shall go to his post after passing the training exam.
11.2 Operators working in the dangerous areas with dust explosive environment shall wear anti-static work clothes and dust masks.
11.3 It shall be checked that the insulation layer of electrical connection wire connecting electrical equipment and tools is in good condition, the electrical equipment is perfectly grounding, and the ignition-proof electrical equipment are under normal condition.
11.4 Before operation, it shall be made sure that there are no dust over the operation position, dust hood or the vacuum cleaner, and the dust in the ash bucket of dust removal facilities or in the dust collecting container (barrel) shall be cleaned.
11.5 The dust removal system shall be turned on 10 minutes before the operation.
11.6 The security check of dust removal system shall be carried out…
11.7 Operation tools producing collision sparks cannot be used, dust in the operation area shall be cleaned in a timely manner.
11.9 When the dust removal system shutdowns abnormally or the dust concentration in the air exceeds the standard in the operation area, or during the non-performing period of dust removal system, the operation shall stop.
11.10 During the operation process, the work involving the use of fire and the maintenance work is not allowed to be carried out. They can be carried out only after the mechanical processing operation of aluminum and magnesium products is completely stopped. Precautions against fire shall be carried out according to requirements during the work involving the use of fire.
Notes by EHS.CN
It is an important but difficult point that how mechanical processing enterprises of aluminum and magnesium products control the dust well. The daily safety management of these enterprises is related to the business operational efficiency, and even determines whether the enterprises can survive, for the case that one explosion destroys a factory takes place again and again. For mechanical processing enterprises of aluminum and magnesium products, the above-mentioned operational safety management measures are compulsory, and for other enterprises producing dust can refer to it or follow it as routine management measures directly.
Fourthly, it is about the dust cleaning.
12.1 The thickness of the dust over the operating places, equipment and facilities shall be less than 0.8mm, and the dust shall be cleaned in a timely manner, the cleansing period and areas include but do not limit to the followings:
Ø areas that should be cleaned at least once during one operation period: the operation post and tools used…
Ø areas that should be cleaned at least once a week: the mechanical processing facilities in the operating area…
Ø areas that should be cleaned at least once a month: walls of the building, doors and windows, floor and grooves in the operating area…
12.2 When cleaning, the cleaning method of not causing raising dust and the cleaning tools of not producing sparks shall be used.
12.3 Dust being cleaned and collected shall be kept away from the corrosion, water or other chemical substances or be prevented from self-ignition caused by the exothermal reaction of dampness, shall be placed into the containers (barrels) made from non-aluminum metal materials or antistatic materials whose surface has been through the anti-rust treatment, and the dust collected shall go through the harmless treatment.
Conclusion by EHS.CN
It is well known that how dangerous dust is. Every EHS person knows, but bosses or superiors may not. People can catch pneumoconiosis when exposed in the dust, which is a chronic disease. If the dust explodes, it may make you loss your job, be put into prison or even be sentenced to death.
EHS personnel working for enterprises with serious dust risk or dangerous areas of dust explosion might make a list of all laws and regulations related to dust (compulsory and recommendatory), carefully looking into them one by one, transfer them into the corporate management system and measures for dust and implement them strictly.
Meanwhile, EHS personnel also need to collect latest news reports, icons, videos, cases related to safety accidents of dust explosions, and provide them to bosses and the front-line staff utile the boss support EHS personnel's work and until the front-line staff follow the safety management system and rules related to dust.
Therefore, the danger of dust explosion can be minimized, enterprises can survive for long, and the sustainable development will be possible.