Toxicity and protection against hydrocyanic acid

Hydrocyanic acid has relatively low toxicity and corrosivity; as long as appropriate personal protective equipment is worn, such as rubber gloves. That will do. But do not get it in the eyes or ingest it.

Class A inorganic highly toxic substance; health hazards: inhibits respiratory enzymes, causing cellular asphyxiation. Acute poisoning: Inhaling high concentrations of hydrogen cyanide gas over a short period of time can cause immediate respiratory failure and death. Clinically, non-sudden deaths are divided into 4 stages: the prodromal stage is characterized by mucosal irritation, increased and deepened breathing, fatigue, and headache ； Oral administration can cause numbness on the tip of the tongue and in the mouth. During the dyspnea phase, there is shortness of breath, elevated blood pressure, and bright red skin and mucous membranes. During the convulsive phase, seizures, coma, and respiratory failure occur. During the paralytic phase, all muscles of the body become relaxed, respiration and heartbeat cease, leading to death. It can cause burns to the eyes and skin, and poisoning upon absorption. Chronic effects: neurasthenic syndrome, dermatitis. 　Emergency response: Quickly evacuate people from the area contaminated by the leak to a safe zone, and immediately establish a 150-m exclusion zone with strict access controls. Cut off the source of fire. It is recommended that emergency responders wear self-contained positive-pressure breathing apparatus and protective suits. Seal the source of leakage as much as possible. Ensure proper ventilation to accelerate diffusion. Diluted and dissolved with spray water. Construct dikes or dig pits to contain the large amount of wastewater generated. If possible, it should be set on fire to prevent the accumulation of toxic gases. Alternatively, the residual gas or escaping gas can be sent to a scrubber tower or a fume hood connected to the tower using an exhaust fan. Leaking containers must be properly handled, repaired, and inspected before being used again. Operational precautions: Ensure strict sealing, and provide adequate local exhaust ventilation as well as general ventilation. Operators must receive specialized training and strictly adhere to the operating procedures. It is recommended that operators wear isolated respirators, full-body adhesive gas-proof suits, and rubber gloves. Stay away from sources of fire and heat; smoking is strictly prohibited in the workplace. Use explosion-proof ventilation systems and equipment. Prevent gases or vapors from leaking into the workplace air. Avoid contact with oxidizers, acids, and bases. Handle with care during transportation to prevent damage to the cylinders and accessories. Equipped with fire-fighting equipment of appropriate types and quantities, as well as emergency response equipment for leaks. Empty containers may still contain harmful substances. For other details, see its MSDS.

Choose polyvinyl fluoride plastic pipes as the material for storage and delivery pipelines; never use iron piping fittings. LC50: 1044 mg/m3 (inhalation by rats). Respiratory protection: When there is a possibility of exposure to its fumes, wear a self-priming filter-type respirator (full-face mask) or an air respirator. It is recommended to wear an oxygen respirator during emergency rescue or evacuation. Eye protection: Protection is provided under respiratory protection. Body protection: Wear rubber acid- and alkali-resistant clothing. Hand protection: Wear rubber acid- and alkali-resistant gloves. Other protections: Smoking, eating, and drinking are prohibited at the work site. Once the work is done, take a shower and change. Store the clothes contaminated with toxins separately and wash them before using them again. Maintain good hygiene* habits

Adding to what the beautiful moderator upstairs said, the original poster can refer to the MSDS of hydrocyanic acid for information. [Hazardous properties]: Its vapors can form explosive mixtures with air, and it can catch fire and explode when exposed to open flames or high temperatures. It reacts violently with nitrates, nitrites, and chlorates, posing a risk of explosion. In the event of high temperatures, a polymerization reaction can occur, releasing large amounts of heat that may cause the container to rupture and lead to an explosion. 【Fire extinguishing method】: Firefighters must wear specialized full-body protective gear and oxygen respirators, and operate from a safe distance or with protective measures in place. Extinguishing agents: alcohol-resistant foam, water mist, dry powder, sand. 7: Precautions for storage and transportation 【Precautions for storage and transportation】: Store in a cool, well-ventilated warehouse. Keep away from flames and heat sources. Avoid light exposure. The storage temperature should not exceed 30°C. Keep the container sealed. It should be stored separately from oxidizers, alkalis, and food chemicals; mixed storage is strictly prohibited. Use explosion-proof lighting and ventilation facilities. The use of mechanical equipment and tools that may generate sparks is prohibited. The storage area should be equipped with emergency response equipment for leaks and appropriate containment materials. The \"five pairs\" management system for highly toxic substances must be strictly implemented. 8: Protective measures 【China MAC】: 0.3 【Former Soviet Union MAC】: No standard established 【Detection method】: Sodium nicotinate-barbituric acid sodium colorimetric method 【Engineering controls】: Strict sealing is required, along with adequate local exhaust and general ventilation. Maximize mechanization and automation. Provide safety showers and eye wash stations. 【Respiratory Protection】: When there is a possibility of exposure to toxic substances, a self-priming filter-type respirator (full-face mask) must be worn. It is recommended to wear an oxygen respirator if necessary. 【Eye protection】: Protection is provided under respiratory protection. 【Body Protection】: Wear a one-piece adhesive gas mask suit. 【Hand protection】: Wear rubber gloves. 【Other protections】: Smoking, eating, and drinking are prohibited at the work site. Once the work is done, clean thoroughly. Store the clothes contaminated with toxins separately and wash them before using them again. The workshop should be equipped with first-aid equipment and medicines. Workers should learn self-rescue and mutual rescue.

Here is a more comprehensive version: Hydrocyanic acid – Composition/information on components, Hazardous components, Concentration, CAS No. Hydrocyanic acid: 74-90-8. Overview of hazards: Hazard category: Class 6.1 – Toxic substances. Routes of exposure: Inhalation, ingestion, dermal absorption. Health hazards: Inhibits respiratory enzymes, leading to cellular asphyxiation. Acute poisoning: Inhaling high concentrations can cause sudden death. The clinical manifestations in cases that are not fatal suddenly are divided into 4 stages: the prodromal stage is characterized by mucosal irritation, increased and deepened breathing, fatigue, and headache ； Oral administration can cause numbness of the tip of the tongue and in the mouth. During the dyspnea phase, there is shortness of breath, elevated blood pressure, and bright red skin and mucous membranes. During the convulsive phase, seizures, coma, and respiratory failure occur. During the paralytic phase, all muscles of the body become relaxed, respiration and heartbeat cease, leading to death. It can cause burns to the eyes and skin, and poisoning upon absorption. Chronic poisoning: neurasthenic syndrome, dermatitis. Environmental hazards: Flammability and explosion risk: This product is flammable and highly toxic. First aid measures: Skin contact: Immediately remove contaminated clothing and rinse thoroughly with flowing water or a 5% sodium thiosulfate solution for at least 20 minutes. Seek medical attention. Eye contact: Immediately lift the eyelids and rinse thoroughly with plenty of flowing water or saline for at least 15 minutes. Seek medical attention. Inhalation: Quickly move to a place with fresh air. Keep the airways clear. If there is difficulty breathing, administer oxygen. When breathing and heartbeat stop, perform artificial respiration immediately (do not use mouth-to-mouth) and chest compressions. If isopentyl nitrite is inhaled, seek medical attention. Ingestion: Drink plenty of warm water and induce vomiting. Gastric lavage should be performed using a 1:5000 potassium permanganate solution or a 5% sodium thiosulfate solution. Seek medical attention. Fire prevention measures: Hazardous properties: Its vapor can form explosive mixtures with air, and it can catch fire and explode in the presence of open flames or high heat. It reacts violently with nitrates, nitrites, and chlorates, posing a risk of explosion. In the event of high temperatures, a polymerization reaction can occur, releasing large amounts of heat that may cause the container to rupture and lead to an explosion. Harmful combustion products: nitrogen oxides, carbon monoxide, carbon dioxide. Fire extinguishing method: Firefighters must wear specialized full-body protective gear and oxygen respirators, and operate from a safe distance or with protective measures in place. Extinguishing agents: alcohol-resistant foam, water mist, dry powder, sand. Emergency response to leaks: Evacuate people from the area contaminated by the leak to a safe zone promptly, and immediately establish a 150-m exclusion zone to strictly restrict access. Cut off the source of fire. It is recommended that emergency responders wear self-contained positive-pressure breathing apparatus and protective suits. Do not come into direct contact with the spill. Seal the source of leakage as much as possible. Prevent entry into confined spaces such as sewers and drainage ditches. Minor leaks: Absorb or adsorb using sand or other non-flammable materials. Collected in a sealed container. Large-scale leakage: Build dikes or dig pits to contain it. Cover with foam to reduce vapor damage. Spray water to cool and dilute the steam, protecting personnel on site, but do not spray water directly at the leak site. Transfer to a tank truck or specialized collector using an explosion-proof pump, and recycle it or transport it to a waste disposal facility for disposal. Handling and Storage: Handling precautions: Maintain strict closure, and provide adequate local exhaust ventilation as well as general ventilation. Operate as mechanically and automatically as possible. Operators must receive specialized training and strictly adhere to the operating procedures. It is recommended that operators wear self-priming filter-type gas masks (full-face masks), disposable rubber-coated gas protection suits, and rubber gloves. Stay away from sources of fire and heat; smoking is strictly prohibited in the workplace. Use explosion-proof ventilation systems and equipment. Prevent steam from leaking into the workplace air. Avoid contact with oxidizers and alkalis. Handle with care during transportation to prevent damage to the packaging and containers. Equipped with fire-fighting equipment of appropriate types and quantities, as well as emergency response equipment for leaks. Empty containers may still contain harmful substances. Storage precautions: Store in a cool, well-ventilated warehouse. Keep away from flames and heat sources. Avoid light exposure. The storage temperature should not exceed 30°C. Keep the container sealed. It should be stored separately from oxidizers, alkalis, and food chemicals; mixed storage is strictly prohibited. Use explosion-proof lighting and ventilation facilities. The use of mechanical equipment and tools that may generate sparks is prohibited. The storage area should be equipped with emergency response equipment for leaks and appropriate containment materials. The \"five pairs\" management system for highly toxic substances must be strictly implemented. Contact control/Personal protection: Occupational exposure limit: MAC (mg/m3): 1; TWA (mg/m3): --; STEL (mg/m3): --. Monitoring method: Sodium nicotinate-sodium barbital colorimetric method. Engineering controls: Strict sealing, along with adequate local exhaust and general ventilation. Maximize mechanization and automation. Provide safety showers and eye wash stations. Respiratory protection: When there is a possibility of exposure to toxic substances, a self-priming filter-type respirator (full-face mask) must be worn. It is recommended to wear an oxygen respirator if necessary. Eye protection: Protection is provided under respiratory protection. Body protection: Wear a one-piece adhesive gas mask suit. Hand protection: Wear rubber gloves. Other protections: Smoking, eating, and drinking are prohibited at the work site. Once the work is done, clean thoroughly. Store the clothes contaminated with toxins separately and wash them before using them again. The workshop should be equipped with first-aid equipment and medicines. Workers should learn self-rescue and mutual rescue.