Questions and Corrections on GBT50493
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In chemical enterprises, alarm installation and explosion-proof electrical equipment are the two on-site aspects where major hazards are most easily identified. The 2019 version of the alarm standards was finally released after much anticipation, but it contained surprisingly many new provisions. Therefore, I believe it is necessary to gather insights to sort things out, and I also hope that the drafting team can provide application guidelines. Term 2.0.1: Liquefied natural gas (Liquefied methane does not belong to liquefied hydrocarbons.) Term 2.0.2’s definition of toxic gases is likely to be the most controversial. The new version of the standards expands the category of toxic gases to include not only those that are highly toxic but also acute toxic gases classified as Category 1 and Category 2; the toxic gases listed in the \"Specifications for the Installation of Toxic Gas Detection and Alarm Devices in Workplaces\"; and the chemical hazards listed in \"Occupational Exposure Limits for Hazardous Factors in Workplaces – Part 1: Chemical Hazards\". In particular, according to GBZ2.1 version 2019, there are 358 different chemical substances (with no updates to the explanatory text), covering most common flammable gases and liquids – though ethanol is not included – such as methanol, toluene, and ethyl acetate. Under the new standard 50493, alarm devices for toxic gases must be installed for all of these substances. There are also obvious errors in this provision’s explanation: “...Toxic gases refer to those with an acute toxicity hazard category of 1 or 2, which are toxic gases posing severe hazards.” Common ones include: nitrogen dioxide, hydrogen sulfide, benzene, hydrogen cyanide, ammonia, chlorine, carbon monoxide, acrylonitrile, vinyl chloride, phosgene (carbonoyl chloride), etc. Some of these are not gases but liquids; ammonia falls into acute toxicity category 3, while benzene and vinyl chloride do not have acute toxicity. I’ve taken a quick look at this; it’s quite important to me. Everyone, please go ahead.
This post was last edited by ZhiGE on 2019-12-16 at 16:56. Personal opinion: 1. Liquefied natural gas (whose main component is methane) should be considered liquefied hydrocarbons. Baidu: Hydrocarbons, also known as hydrocarbon compounds (in English: hydrocarbon), are a type of organic compound. This compound is composed of only carbon and hydrogen, and includes alkanes, alkenes, alkynes, cyclohydrocarbons, and aromatic hydrocarbons; it serves as a backbone for many other organic compounds. Liquefied hydrocarbons refer to hydrocarbons that are turned into a liquid state by means of pressure or temperature reduction, such as ethane, ethylene, propylene, and liquefied petroleum gas; in other words, hydrocarbons that become liquid as a result of pressure or cooling are liquefied hydrocarbons. 2. Of the 14 common toxic gases and vapors listed in GB50493-2019, not all are gases. Other gases were not included in the design standards because they are not common, or there are no suitable online detectors for them; therefore, other instruments are required for measurement in order to meet safety and occupational health requirements. 3. Note a significant change: The standard GB 50493-2009, Design Code for Detection and Alarm of Flammable and Toxic Gases in Petrochemical Industries, has been revised to GBT 50493-2019, Design Standard for Detection and Alarm of Flammable and Toxic Gases in Petrochemical Industries. It has changed from a mandatory standard to a recommended one; items not listed in the standard can be reasonably configured based on actual conditions, on-site circumstances, and the capabilities of the detectors. 4. The revision of a standard involves the participation of **regulatory agencies (the Ministry of Emergency Management, health and labor protection authorities), design institutes, manufacturers, and experts from end-users**, as well as reference to foreign standards and specifications. It is a lengthy process marked by negotiation and compromise; major principled issues should not arise.
This post was last edited by yu*nyang_01 on 2020-1-9 at 18:48. From the perspective of the new petrochemical regulations, LNG is gradually being adopted as a liquefied hydrocarbon by default. I work in chemical safety, so I cannot agree with other opinions. There is no clear distinction anymore between mandatory and voluntary tasks; if it’s written down, one has to carry it out – that’s just the reality of the current environment, and there’s nothing that can be done about it. You should take a close look at the explanation section for clause 2.0.2; if you also understand occupational health, you will be able to see even better just how chaotic things are.