Hydrofluorocarbon 152a
Also known as: Hydrofluorocarbon 152a, HFC-152a, 1,1-difluoroethane
Overview
1,1-difluoroethane, commonly known as Hydrofluorocarbon 152a (HFC-152a), is a synthetic hydrofluorocarbon gas. It is not naturally occurring and is not a nutritional or dietary supplement ingredient. Its primary industrial application is as a propellant in various aerosol products, including pharmaceutical metered-dose inhalers (pMDIs) and cosmetic sprays. HFC-152a was developed as a replacement for older chlorofluorocarbons (CFCs) due to its significantly lower ozone depletion potential. It is a volatile gas with physical properties suitable for propellant use. While it exhibits anesthetic properties at very high concentrations, its utility is solely based on its physical characteristics as a propellant, not on any nutritional or therapeutic effects. Extensive toxicological and safety data, including chronic inhalation studies in animals and assessments by expert panels like the Cosmetic Ingredient Review (CIR), have characterized its safety profile.
Benefits
HFC-152a is not used for health benefits or supplementation and does not possess documented nutritional or pharmacological benefits in humans. Its sole role is as an inert propellant in aerosol products, facilitating the delivery of active ingredients in pharmaceutical inhalers or cosmetic sprays. Therefore, there are no direct health benefits associated with its use or consumption as a supplement. At extremely high exposure levels, far beyond typical use, HFC-152a can exhibit anesthetic properties, but this is considered a toxicological effect rather than a therapeutic benefit and is not a basis for its use.
How it works
HFC-152a functions purely as a physical propellant. It is a compressed gas that, when released from an aerosol can, expands rapidly, expelling the product. It does not interact with biological systems in a beneficial way. At very high concentrations, it acts as a central nervous system depressant, leading to anesthetic effects, but this is a toxicological response, not a therapeutic mechanism. When inhaled, it is absorbed rapidly, and pharmacokinetic studies in inhaler formulations focus on ensuring the safety and efficacy of the active drug being delivered, not the HFC-152a itself. There are no known specific molecular targets for therapeutic use.
Side effects
The Cosmetic Ingredient Review (CIR) Expert Panel has concluded that HFC-152a is safe for use as a propellant in cosmetic products at current exposure levels, with no evidence of carcinogenicity or systemic toxicity at typical use concentrations. Chronic inhalation studies in rats showed no distinct toxicity or carcinogenicity even at high ppm exposures. Common side effects observed in animal studies at very high doses included non-specific clinical signs like ocular/nasal discharge, wet/stained perinea, stained body/face, and swollen ears, though these were also seen in control groups and not clearly treatment-related. Uncommon side effects noted in female rats at all concentrations included increased lung, stomach, heart, and liver weights, the biological significance of which remains unknown. Rare side effects, such as cardiac arrhythmias, have been observed in dogs at extremely high exposure levels (150,000 ppm). There are no documented drug interactions. HFC-152a is not applicable as a supplement, and inhalation exposure should be controlled to avoid anesthetic or toxic effects. Safety conclusions are primarily based on animal inhalation studies and occupational exposure limits, with no specific data on vulnerable human populations.
Dosage
HFC-152a is not a therapeutic agent or supplement, so there is no minimum effective dose, optimal dosage range, or maximum safe dose for health benefits. It is used as a propellant gas in aerosol formulations, and human exposure is incidental to product use. Occupational exposure limits are set far below concentrations known to cause toxicity in animals. Chronic exposure studies in animals have shown no significant adverse effects at concentrations up to 25,000 ppm. It is rapidly absorbed via inhalation. There are no required cofactors or specific timing considerations for its use, as it is not intended for direct biological effect.
FAQs
Is Hydrofluorocarbon 152a a dietary supplement?
No, Hydrofluorocarbon 152a (HFC-152a) is a propellant gas used in aerosol products like cosmetic sprays and pharmaceutical inhalers, not a dietary supplement.
Is it safe to inhale?
At typical product use levels, HFC-152a is considered safe for inhalation. However, at very high concentrations, it can cause anesthetic and cardiac effects.
Does it provide health benefits?
No, HFC-152a does not offer any direct health benefits. Its purpose is to facilitate the delivery of active ingredients in inhalers or other spray products.
Can it cause toxicity?
Toxicity from HFC-152a occurs only at extremely high inhalation concentrations, far exceeding typical exposure levels from product use.
Research Sources
- https://www.ecetoc.org/wp-content/uploads/2014/08/JACC-045.pdf – This document, likely a Joint Assessment of Commodity Chemicals (JACC) report, details a chronic inhalation study in rats exposed to HFC-152a. The study found no distinct evidence of toxicity or carcinogenicity over two years, even at high concentrations (up to 25,000 ppm), supporting a favorable long-term safety profile for the compound.
- https://www.cir-safety.org/sites/default/files/hydrofluorocarbon%20152a.pdf – This is the Cosmetic Ingredient Review (CIR) Expert Panel's safety assessment of HFC-152a. The panel reviewed extensive toxicity data, including acute, subchronic, and chronic inhalation studies, concluding that HFC-152a is safe for use as a propellant in cosmetic products at typical exposure levels, finding no adverse health effects.
- https://liebertpub.com/doi/full/10.1089/jamp.2024.0023 – This source discusses the regulatory review of HFC-152a as a propellant in reformulated pharmaceutical metered-dose inhalers (pMDIs). It focuses on aspects like bioequivalence and safety in drug delivery, indicating that no direct therapeutic effects or toxicity concerns were identified at clinical inhaler doses.
- https://hpvchemicals.oecd.org/ui/handler.axd?id=6415a8cf-4a7b-4c8e-b943-f61ed5304b0d – This OECD document provides a comprehensive summary of the toxicology of 1,1-difluoroethane (HFC-152a). It details various studies, including those showing anesthetic properties at very high concentrations and cardiac sensitization in animals, providing a broad overview of its safety profile and potential hazards at extreme exposure levels.
