Emergency Medicine Journal 2024

Original research

Table 1 LCIA results of Penthrox Broad category Category

Result

LCIA method (units)

Description

Climate change

0.83965 0.0036 16.09807

IPCC 2013 GWP 100a (kg CO 2 Eq.) ILCD 2011 Midpoint+ (mol H+Eq.) ILCD 2011 Midpoint+ (CTUe) ILCD 2011 Midpoint+ (kg PO 4 Eq.)

Potential for global warming from greenhouse gas emissions. Acidification of soil and freshwater due to gas release. Harmful effect of toxic substances on freshwater organisms. Changes in freshwater organisms and ecosystems caused by excess nutrients. Changes in saltwater organisms and ecosystems caused by excess nutrients. Changes in land organisms from excess nutrients in soil and air. Harm to human health that causes or increases cancer risk. Potential damage to human DNA from ionising radiation. Harm to human health that is not related to cancer or ionising radiation. Air emission causing stratospheric ozone layer destruction. Harm to humans from has emission that contribute to smog in the lower atmosphere. Harm to humans caused by particulate matter emission. Non-renewable energy consumption or abiotic depletion potential. Depletion of natural resources, change in soil quality and reduction in biodiversity.

Impacts on ecosystems

Acidification

Ecotoxicity freshwater

Eutrophication freshwater 0.00047

Eutrophication marine

0.00079

ILCD 2011 Midpoint+ (kg N Eq.)

Eutrophication terrestrial

0.00768 5.72E-10 0.02794

ILCD 2011 Midpoint+ (mol N Eq.) ILCD 2011 Midpoint+ (CTUh) ILCD 2011 Midpoint+ (kBg U235 Eq.)

Impacts on human health

Carcinogenic effects Ionising radiation

Non-carcinogenic effects 1.13E-08

ILCD 2011 Midpoint+ (CTUh)

Ozone layer depletion Photochemical ozone formation

3.18E-06 0.00227

ILCD 2011 Midpoint+ (kg CFC-11 Eq.) ILCD 2011 Midpoint+ (kg NMVOC Eq.)

Particulate matter formation

3.44E-08

PM method (disease incidence)

Depletion of resource

Fossil fuels

9.25198

CML-IA baseline (MJ)

Land use

4.80724

Soil quality index based on LANCA (points)

Minerals and metals

5.37E-06 0.20422

CML-IA baseline (kg Sb Eq.)

Depletion of natural non-fossil fuel resources.

Water use Water taken from the environment. AWARE, Available Water Remaining; CML-IA, Centrum voor Milieukunde Leiden; Eq., equivalent; GWP, global warming potential; ILCD, International Reference Life Cycle Data System; IPCC, International Panel on Climate Change; LANCA, Land Use Indicator Value Calculation in Life Cycle Assessment; LCIA, life cycle impact assessment; PM, particulate matter. AWARE (m 3 water Eq.)

LCIAs can be compared for different products. Freshwater eutrophication has the largest normalised impact (figure 4). Disability-adjusted life years The analysis delivered DALYs for eight impact categories. Global warming was the greatest contributor (7.79E-07, representing 83.49% of total DALY impact) and the second largest contrib- utor was water consumption (DALY: 1.50E-07, 16.08% of total DALY impact).

Climate change impact data were available for intravenous 100 mg in 100 mL morphine sulfate. 22 A comparative dose of intra- venous morphine sulfate to 3 mL of methoxyflurane in trauma is 0.1 mg/kg as shown by Mercadente et al . 9 For the compar- ison, an adult weighing 70 kg was used. We assumed that the remaining morphine is not discarded. Data from E copassenger. com for CO 2 e of different types of transport between Newcastle upon Tyne and London was also gathered. 23 RESULTS The 16 impact category raw results of the LCIA of Penthrox are presented in table 1, with initial overarching broad categories, corresponding descriptions, units and LCIA methods. Contribution analysis Figure 3 shows a contribution analysis for each impact category. Across 15 of the 16 impact categories, raw materials and the production process contributed to most of the impact. For the ozone depletion category, methoxyflurane manufacture contrib- uted 98% of the ozone layer depletion impact due the assumed use of tricholoromethane in reaction 1 of manufacturing methoxyflurane (online supplemental appendix 2). Specifically for climate change impact, the highest contrib- uting parts of the life cycle assessment of Penthrox were raw materials (34.40%) and the production process (29.81%). The lowest contributing categories were transport (3.28%) and manufacture of drug (6.52%) with disposal contributing around a quarter of the impact (25.97%). Normalised impact A normalised impact of 1.0 would represent the environmental impact expected for one person in 1 year in the respective cate- gory. The normalised impact is another way in which different

Figure 3 Percentage contribution analysis of life cycle impact assessment (LCIA) of Penthrox. The graph shows how impact of five separate parts of the LCIA (raw materials, methoxyflurane manufacture, production process, transport and disposal) contribute to the impact across the 16 impact categories described in table 1. Methoxyflurane manufacture is considered as a separate category to raw materials and production process.

Martindale AEV, et al . Emerg Med J 2024; 41 :69–75. doi:10.1136/emermed-2022-213042