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Environment and health
Published in Sally Robinson, Priorities for Health Promotion and Public Health, 2021
Tristi Brownett, Joanne Cairns
Ozone depletion is not entirely responsible for climate change because as the earth orbits around the sun there is also a natural global warming of the planet. This natural warming is exacerbated by solar events such as solar flares or the trapping of particles and gases from volcanic eruptions, sea salt and Saharan dust (Highwood, 2018). The recent escalation in global warming is due to an increase in these trapped gases and particles which affect the usual functioning of the stratosphere and its neighbouring troposphere. These gases, which are sometimes called greenhouse gases, include carbon dioxide, methane, nitrous oxide, CFCs and hydrofluorocarbons (HFCs). When released into the stratosphere, they accumulate and essentially act as a planetary quilt allowing heat from the sun to enter the earth’s stratosphere, but not to escape so easily. This is the enhanced ‘greenhouse effect’ (IPCC, 1988).
Overview of the delivery technologies for inhalation aerosols
Published in Anthony J. Hickey, Heidi M. Mansour, Inhalation Aerosols, 2019
Daniel F. Moraga-Espinoza, Ashlee D. Brunaugh, Silvia Ferrati, Lara A. Heersema, Matthew J. Herpin, Patricia P. Martins, Hairui Zhang, Hugh D.C. Smyth
Currently, pMDIs may be subject to a similar need for redesign after the Kigali amendment in the last Montreal Protocol revision (October 2016). This time, an international phase-down agreement for fluorinated gases was signed, wherein 197 countries agreed to cut the production and consumption of hydrofluorocarbons (HFCs) by more than 80% over the next 30 years (68). Therefore, HFCs such as HFA 134a and HFA 227, both used for orally inhaled and nasal drug products (OINDPs), may eventually be replaced by alternatives. At present, several candidates may exist. For example, HFA 152a has a global warming potential (GWP) ten times lower than HFA134a or 227 but a similar vapor pressure (Table 7.2), and it has preliminary data demonstrating formulation of pMDI solution and suspensions with comparable cascade impaction stage deposition profiles to HFA134a formulations (Figure 7.3) (69).
Hair Styling/Fixative Products
Published in Dale H. Johnson, Hair and Hair Care, 2018
Joseph A. Dallal, Colleen M. Rocafort
It has been demonstrated in the literature that acceptable long-term stability of 80% VOC aerosol hair sprays is possible with an array of polymers and carefully chosen inhibitors, with either hydrofluorocarbon-152a/hydrocarbon blends, dimethyl ether/hydrocarbon blends, dimethyl ether, or hydrocarbon alone, and are on the market now. Work is still in progress for 55% VOC systems.
Acute, repeated inhalation toxicity, respiratory system irritation, and mutagenicity studies of 1,1,2,2-tetrafluoroethane (HFC-134) as the impurity in the pharmaceutical propellant 1,1,1,2-tetrafluoroethane (HFA-134a)
Published in Drug and Chemical Toxicology, 2023
Yanjun Zhao, Huimin Sun, Fei Lin, Huiying Yang
The American Industrial Hygiene Associations Workplace Environmental Exposure Level Committee recommends a permissible exposure level for HFC-134 of 1000 ppm (Workplace Environmental Exposure Level 2019) as an 8-h time-weighted average. But due to the high frequency of use of aerosols by asthma patients, acceptance criteria of HFC-134 as the impurity in aerosol propellant HFA-134a should be lower than 1000 ppm to ensure the safety of aerosol products. It is worth mentioning that hydrofluorocarbons (HFCs) have been listed as a phase-out substance by amendment to the Montreal Protocol (The Kigali Amendment 2016) due to their high global warming potential (GWP), so it is very difficult to obtain the test material of HFC-134, which leads to the inhalation toxicity test only conducted for 21 days, subchronic and chronic toxicity should be further conducted if more properties need to be known.
Impact of choice of inhalers for asthma care on global carbon footprint and societal costs: a long-term economic evaluation
Published in Journal of Medical Economics, 2022
Kalé Kponee-Shovein, Jessica Marvel, Ryotaro Ishikawa, Abhay Choubey, Harneet Kaur, Khadidja Ngom, Iman Fakih, Natalia Swartz, Todd Schatzki, James Signorovitch
HFAs are already a target of global efforts to reduce GHG emissions. Unsurprisingly, environmental policy has historically focused on HFA use in industrial and refrigerant applications, which account for over 90% of HFA emissions6, while delaying or avoiding targeting inhalers due to economic and patient health considerations such as patient-borne costs, patient ability, and patient preference11,12. Notably, HFAs in inhalers are currently exempt from the HFA phase-out under the Kigali Amendment to the Montreal Protocol and are excluded from current EU regulations on fluorinated gases (F-gas), which are man-made gases, including hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), that are often used as substitutes for ozone-depleting substances7,12,13. In the United States, recent legislation requires the Environmental Protection Agency to set necessary allowances for use of hydrofluorocarbons in MDIs to meet quantities needed “based on projected, current, and historical trends”14. Currently, the use of MDIs accounts for only 2.3% of the F-gas contribution to global emissions15 or less than 0.1% of global GHG emissions16. Nevertheless, as demand for MDIs increases due to global population growth and increased asthma prevalence, and as F-gases are phased out from other sectors and applications, MDIs will represent a growing proportion of F-gas use across the globe and will continue to contribute to climate change. Thus, understanding the greenhouse gas emissions and costs implications of efforts aiming to reduce the carbon footprint of MDIs is important for future policy.
Skeletal fluorosis secondary to harmful inhalant use
Published in Clinical Toxicology, 2022
Derek J. Fikse, Danny Le, Ryan M. Surmaitis
Inhalants are easily obtained from local retail chain or hardware stores. Inhalant use commonly produces central nervous system effects, such as euphoria, and cardiac dysrhythmias [1]. Compressed air used for computer cleaning commonly contains hydrofluorocarbons such as 1,1-difluoromethane. Fluoride-containing substances may induce osteosclerotic changes and increase bone turnover [2]. Skeletal fluorosis should be considered for patients with diffuse bony lesions and a history of chronic inhalant use.