Fluoroantimonic acid is a colorless liquid created by mixing hydrogen fluoride and antimony pentafluoride. This substance is globally recognized as the strongest superacid, a category defined by acidity exceeding that of 100% pure sulfuric acid. The acid’s strength is measured using the Hammett acidity function (\(H_0\)), where fluoroantimonic acid registers a value vastly more negative than pure sulfuric acid’s \(H_0\) of -12. Its extreme acidity stems from the formation of the fluoroantimonate anion, which is an exceptionally weak base, allowing the proton to be donated with great ease.
Restrictions on Public Access
Chemical suppliers refuse sales of fluoroantimonic acid to non-institutional buyers. This refusal is due to the extreme hazards and the stringent regulatory framework governing highly toxic and corrosive substances. A person attempting to place an order without a verified institutional affiliation, such as a university, licensed chemical manufacturer, or accredited research laboratory, cannot complete the transaction.
The procurement process restricts access to those operating under controlled and regulated environments. Vendors require an established business account linked to a verifiable organization and mandate that the individual placing the order be an “authorized individual” knowledgeable about chemical safety. This prevents casual acquisition, as the material is classified as acutely toxic and severely corrosive by multiple regulatory bodies. Many jurisdictions also impose age restrictions on corrosive products, sometimes making delivery to a residential address a criminal offense.
Purchases of highly hazardous materials are subject to internal review by the institution’s Environmental Health and Safety (EHS) department before the order is placed. This review ensures the facility has the necessary safety protocols, storage capacity, and disposal plans in place. The liability and regulatory burden associated with this superacid mean that chemical suppliers will not risk sale outside of established, compliant business-to-business channels.
Industrial and Research Procurement Channels
Authorized institutions must navigate a complex regulatory system to acquire fluoroantimonic acid. The process requires specialized documentation to verify the legitimacy of the intended use and user. This often includes an End-User Certificate (EUC), a legally binding document where the purchaser attests to the chemical’s intended application and certifies it will not be used for prohibited purposes, such as chemical weapons development.
The substance is frequently supplied under a specific regulatory exemption, such as the Toxic Substances Control Act (TSCA) research and development (R&D) exemption in the United States. The recipient must comply with the exemption’s requirements and is prohibited from using the chemical for non-exempt commercial purposes without the supplier’s written consent. This documentation is crucial for the supplier to maintain compliance with federal and international regulations.
Logistical compliance for transport is governed by stringent Hazardous Materials (HazMat) regulations, such as those set forth in Title 49 of the U.S. Code of Federal Regulations (49 CFR). As a high-hazard, Packing Group I material, the acid requires specialized packaging, specific hazard communication labels, and detailed shipping papers. It must be shipped in containers made of highly resistant fluoropolymers, like polytetrafluoroethylene (PTFE) or perfluoroalkoxy alkane (PFA), because it attacks glass and most other materials. This necessity for specialized packaging and highly regulated shipping contributes significantly to the material’s extreme cost.
Extreme Hazards and Safety Protocols
Restrictions on purchasing fluoroantimonic acid are driven by its extreme chemical and physical dangers. The acid is so corrosive that it is classified as fatal if swallowed, inhaled, or absorbed through the skin. It reacts violently and explosively upon contact with water, making even atmospheric moisture a significant handling hazard.
The acid’s danger is compounded because its decomposition or reaction can generate highly toxic and volatile components. When heated to only 40°C (104°F), the acid decomposes, releasing gaseous hydrogen fluoride, which is intensely toxic and can cause severe systemic poisoning through skin absorption. The antimony component can also form toxic antimony compounds, adding a heavy metal poisoning risk.
Specialized engineering controls are an absolute necessity for safe handling. Storage must be in sealed containers made of PTFE or PFA to prevent corrosion and decomposition. Any work with the acid must be conducted within a high-performance, specialized fume hood designed to capture and neutralize the volatile and toxic fumes. Required Personal Protective Equipment (PPE) is extensive, including chemical-resistant suits, face shields, and specialized chemical-resistant gloves, as the acid rapidly degrades most standard laboratory gloves. Even with these precautions, emergency response protocols must be in place, as immediate flushing of affected areas and specialized medical attention are required in the event of accidental exposure.