Should a combustible gas detector or a toxic gas detector be used for methanol?

Methanol is a flammable liquid, so gas detection instruments need to be installed to monitor its concentration. At the same time, methanol is also a toxic substance, so toxic gas detection instruments are needed for monitoring. The OEL (Occupational Exposure Limit) for methanol is a concentration limit per cubic meter of air, used to assess the level of exposure to methanol in the workplace. Level 1 alarm and Level 2 alarm are alarm levels set based on the methanol concentration. The specific OELs, as well as the values for primary and secondary alarms, may vary depending on the region and relevant regulations. You can consult relevant safety materials, industry standards, or guidelines from occupational safety and health agencies to obtain the specific values for the OEL of methanol, as well as the values for the first-level and second-level alarms. Common sources of reference include **, regional occupational safety and health agencies, industrial safety standards, Safety Data Sheets (SDS), etc. These materials usually provide information on safe handling practices for methanol as well as relevant alarm values. .

It is flammable and toxic in a single component, and is usually toxic； Methanol PC-STEL: 50mg/m3, first-level alarm setpoint: 50mg/m3, second-level alarm setpoint: 100mg/m3. For reference: relevant standards such as GB/T50493, GBZ/T223, and GBZ2.1 can be consulted.

Minutes of the seminar on the “Design Standards for Detection and Alarm of Flammable and Toxic Gases in the Petrochemical Industry”: 1. Issue regarding the installation of toxic gas detectors: When installing toxic gas detectors, is it necessary to treat all 56 types of toxic gases listed in GBZ/T 223–2009 “Specifications for the Installation of Detection and Alarm Devices for Toxic Gases in Workplaces”, as well as the 339 chemical hazardous gases listed in GBZ 2.1–2019 “Occupational Exposure Limits for Hazardous Factors in Workplaces – Part 1: Chemical Hazardous Factors”, as toxic gases? Reply: GBZ/T 223–2009 is a standard related to occupational health and safety; the list of toxic gases therein is provided as an appendix and does not have to be followed in GDS design. GBZ 2.1–2019 is also a standard related to occupational health and safety, focusing on the OEL values for toxic gases in the working environment. The list of chemical hazardous gases mentioned in this standard relates to the requirements for occupational health monitoring, and it is not necessary to adhere to it in GDS design. GB/T 50493-2019 is a safety standard that lists common toxic gases used in the petrochemical industry. The list is based on: 1) the 54 gases or vapors specified in the \"Catalogue of Highly Toxic Substances\" issued by the Health and Supervision Department under document No. 142 in 2003; 2) those acute toxic gases classified as Category 1 or Category 2 in terms of acute toxicity, as defined in standard GB 30000.18-2013, \"Classification and Labelling of Chemicals – Part 18: Acute Toxicity\". The toxic gases listed in GBZ/T 223-2009 and GBZ 2.1-2019 cannot be used as a basis for determining toxic gases according to GB/T 50493-2019, but they can be used as a basis for setting the alarm thresholds for toxic gases. When used as a combustible gas detector, methanol does not require to be used as a toxic gas detector.

Both toxic gas and flammable gas alarms need to be set at the temple fair.