ECCS/
Articles/
2505000603
  • Open Access
  • Article
Hydraulic Oil Infiltration into Potable Water through Aircraft Pneumatic Systems: A Qualitative Assessment of Chemical Contamination
  • Kevin Hayes 1, 2, *,   
  • David Megson 1,   
  • Eric Fries 3,   
  • Roxana Sühring 3,   
  • Glen Roberts 2,   
  • Aidan Doyle 1,   
  • Gwen O'Sullivan 2

Received: 09 Feb 2025 | Revised: 24 Apr 2025 | Accepted: 06 May 2025 | Published: 09 May 2025

Abstract

Potable water on aircraft is currently monitored for microbiological contaminants of water quality such as E. coli, but because the source water for aircraft is pre-treated water from municipalities, chemical contaminants are not assessed. This neglects the possibility of aircraft pneumatic systems, interconnected with other systems such as the engines and hydraulic oil reservoirs, from becoming fouled and contaminating the potable water onboard with organophosphate esters and other contaminants of concern. In this novel initial qualitative study potable water samples were taken on twenty domestic and international flights on various commercial aircraft. The samples were analyzed with high-resolution liquid chromatography mass spectrometry and compared against 18 Mohm ultrapure water and tap water blanks drawn from departing airports. Suspect compounds were identified using safety data sheets for commonly used aircraft oils and compounds previously identified in aircraft cabin contamination research. Tributyl phosphate, the primary component in aircraft hydraulic oil, was confirmed to be present in the potable water of the majority of flights sampled (11 of 20 flights). Other organophosphates were also identified in the water on a high percentage of flights (tris (chloropropyl) phosphate (TCPP): 20%; triphenyl phosphate (TPhP): 10%; tris (butoxyethyl) phosphate (TBEP): 10%). The qualification of the compounds is supported by mass accuracy, fragment, isotope abundance, and adduct data. This work suggests that as there is currently a potentially unaddressed occupational and public health risk. Detailed quantitative chemical monitoring of aircraft potable water is therefore recommended to fully establish the magnitude of this risk.

References 

  • 1.
    WorldHealth Organization [WHO]. Guidelines for Drinking-Water Quality: Fourth Edition Incorporating the First 2017. Available online: https://www.who.int/publications/i/item/9789241549950 (accessed on 17 July 2023).
  • 2.
    EuropeanUnion [EU]. Directive on the Quality of Water Intended for Human 2020. Available online: https://eur-lex.europa.eu/eli/dir/2020/2184/oj (accessed on 17 July 2023).
  • 3.
    UnitedStates Environmental Protection Agency [USEPA]. National Primary Drinking Water 2023. Available online: https://www.epa.gov/ground-water-and-drinking-water/national-primary-drinking-water-regulations (accessed on 17 July 2023).
  • 4.
    Governmentof Canada [GC]. Canadian Drinking Water 2022. Available online: https://www.canada.ca/en/health-canada/services/environmental-workplace-health/water-quality/drinking-water/canadian-drinking-water-guidelines.html (accessed on 17 July 2023).
  • 5.
    Moody,P.; Chu, I. Dermal exposure to environmental contaminants in the Great Lakes. Environ. Health Perspect. 1995, 103, 103–114. https://doi.org/10.1289/ehp.95103s9103.
  • 6.
    Shah,; Arjunan, A.; Baroutaji, A.; et al. A review of physicochemical and biological contaminants in drinking water and their impacts on human health. Water Sci. Eng. 2023, 16, 333–344. https://doi.org/10.1016/j.wse.2023.04.003.
  • 7.
    Croddy,; Ackerman, G. Biological and chemical terrorism: A unique threat. In Disaster Nursing and Emergency Preparedness for Chemical, Biological, and Radiological Terrorism, and Other Hazards; Veenema, T.G., Ed.; Springer: Berlin/Heidelberg, Germany, 2019.
  • 8.
    WorldHealth Organization [WHO]. Guide to Hygiene and Sanitation in Aviation, 3rd ; WHO: Geneva, Switzerland, 2009. Available online: https://www.icao.int/safety/aviation-medicine/Suggested%20Literature/guide_hygiene_sanitation_aviation_
  • 9.
    _edition.pdf (accessed on 18 July 2023).
  • 10.
    InternationalCivil Aviation Organization [ICAO]. Water Management at Airports: Eco Airport 2021. Available online: https://www.icao.int/environmental-protection/Documents/Water%20management%20at%20airports.pdf (accessed on 18 July 2023).
  • 11.
    Governmentof Canada [GC]. Potable Water on Board Trains, Vessels, Aircraft and Buses Regulations: Water Samples from Potable Water Systems on Board 2022. Available online: https://laws-lois.justice.gc.ca/eng/regulations/sor-2016-43/page-3.html#docCont (accessed on 18 July 2023).
  • 12.
    EnvironmentalProtection Agency [EPA]. Drinking Water Requirements for States and Public Water Systems: Aircraft Drinking Water 2023. Available online: https://www.epa.gov/dwreginfo/aircraft-drinking-water-rule (accessed on 25 October 2023).
  • 13.
    Handschuh,; O’Dwyer, J.; Adley, C.C. Bacteria that Travel: The Quality of Aircraft Water. Int. J. Environ. Res. Public Health 2015, 12, 13938–13955. https://doi.org/10.3390/ijerph121113938.
  • 14.
    Treglia,; Pallocci, M.; Tenore, G.; et al. Legionella and Air Transport: A Study of Environmental Contamination. Int. J. Environ. Res. Public Health 2022, 19, 8069. https://doi.org/10.3390/ijerph19138069.
  • 15.
    Hayes,; Megson, D.; Doyle, A.; et al. Occupational risk of organophosphates and other chemical and radiative exposure in the aircraft cabin: A systematic review. Sci. Total Environ. 2021, 796, 148742. https://doi.org/10.1016/j.scitotenv.2021.148742.
  • 16.
    Scholz, Routes of Aircraft Cabin Air Contamination from Engine Oil, Hydraulic and Deicing Fluid. INCAS Bull. 2022, 14, 153–170. https://doi.org/10.13111/2066-8201.2022.14.1.13.
  • 17.
    UnitedStates Environmental Protection Agency [USEPA]. Fact Sheet: Final Aircraft Drinking Water 2009. Available online: https://nepis.epa.gov/Exe/ZyPdf.cgi?Dockey=P1005C21.txt (accessed on 18 July 2023).
  • 18.
    Tong,; Wang, J.; Du, X.; et al. Tributyl phosphate degradation and phosphorus immobilization by MnO2: Reaction Condition optimization and mechanism exploration. J. Hazard. Mater. 2022, 415, 128725. https://doi.org/10.1016/j.jhazmat.2022.128725.
  • 19.
    Winder,; Balouet, J.C. Aerotoxic syndrome: Adverse health effects following exposure to jet oil mist during commercial flights. Chest 2010, 99, 9.
  • 20.
    Winder,; Balouet, J.C. The toxicity of commercial jet oils. Environ. Res. Sect. A 2002, 89, 146–164. https://doi.org/10.1006/enrs.2002.4346.
  • 21.
    Liyasova,; Schopfer, L.; Lockridge, O. Cresyl saligenin phosphate, an organophosphorus toxicant, makes covalent adducts with histidine, lysine, and tyrosine residues of human serum albumin. Chem. Res. Toxicol. 2012, 25, 1752–1761. https://doi.org/10.1021/tx3001016.
  • 22.
    Reneman,; Schagen, S.B.; Mulder, M.; et al. Cognitive impairment and associated loss in brain white microstructure in aircrew members exposed to engine oil fumes. Brain Imaging Behav. 2016, 10, 437–444. https://doi.org/10.1007/s11682-015-9395-3.
  • 23.
    Al-Salem,M.; Saquib, Q.; Siddiqui, M.A.; et al. Organophosphorus flame retardant (tricresyl phosphate) trigger apoptosis in HepG2 cells: Transcriptomic evidence on activation of human cancer pathways. Chemosphere 2019, 237, 124519. https://doi.org/10.1016/j.chemosphere.2019.124519.
  • 24.
    Safety Data Sheet: Skydrol LD4 Fire Resistant Hydraulic Fluid. 2016. Available online: http://www.aviaoil.com.ua/pdf/skydrol.ld-4.msds.eng.pdf (accessed on 17 July 2023).
  • 25.
    Safety Data Sheet: Skydrol 5 Hydraulic Fluid. 2019. Available online: https://site.skygeek.com/ssl/MSDS/skydrol-5-hydraulic-fluid-gallon.pdf (accessed on 17 July 2023).
  • 26.
    Safety Data Sheet: Hyjet IV-A Plus. 2023. Available online: https://sds.exxonmobil.com/ (accessed on 17 July 2023).
  • 27.
    Safety Data Sheet: Hyjet V. 2021. Available online: https://sds.exxonmobil.com/ (accessed on 17 July 2023).
  • 28.
    Crump,; Harrison, P.; Walton, C. Aircraft Cabin Air Sampling Study; Part 1 of the Final Report. 2011. Available online: https://dspace.lib.cranfield.ac.uk/items/e2cbe742-1ae3-46a9-bb85-fcb9828e77ca (accessed on 2 May 2025).
  • 29.
    Rosenberger, Effect of charcoal equipped HEPA filters on cabin air quality in aircraft. A case study including smell event related in-flight measurements. Build. Environ. 2018, 143, 358–365. https://doi.org/10.1016/j.buildenv.2018.07.031.
  • 30.
    Schuchardt,; Koch, W.; Rosenberger, W. Cabin air quality—Quantitative comparison of volatile air contaminants at different flight phases during 177 commercial flights. Build. Environ. 2019, 148, 498–507.
  • 31.
    Solbu,; Daae, H.L.; Olsen, R.; et al. Organophosphates in aircraft cabin and cockpit air—Method development and measurements of contaminants. J. Environ. Monit. 2011, 13, 1393–1403. https://doi.org/10.1039/c0em00763c.
  • 32.
    Lombardo, Advanced Aircraft Systems; Tab Books: Blue Ridge Summit, PA, USA, 1993. ISBN: 0-8306-3997-7.
  • 33.
    Wild, Transport Category Aircraft Systems; Jeppesen Sanderson Inc., Co.: Englewood, CO, USA, 1996. ISBN: 0-88487-232-7.
  • 34.
    Brady, Aircraft systems: Hydraulics. 2022. Available online: http://www.b737.org.uk/hydraulics.htm (accessed on 17 July 2023).
  • 35.
    Agencyfor Toxic Substances and Disease Registry [ATSDR]. Toxicological Profile for Phosphate Ester Flame Retardants: Relevance to public Health- Background and Environmental Exposures to Phosphate Ester Flame Retardants in the United 2012. Available online: https://www.atsdr.cdc.gov/toxprofiles/tp202-c2.pdf (accessed on 8 December 2023).
  • 36.
    UnitedStates Environmental Protection Agency [USEPA]. Drinking Water Contaminant List 5-Final. Available online: https://www.federalregister.gov/documents/2022/11/14/2022-23963/drinking-water-contaminant-candidate-list-5-final (accessed on 17 July 2023).
  • 37.
    Gbadamosi,R.; Abdallah, M.; Harrad, S. A critical review of human exposure to organophosphate esters with a focus on dietary intake. Sci. Total Environ. 2021, 771, 144752. https://doi.org/10.1016/j.scitotenv.2020.144752.
  • 38.
    DeRee, ; van den Berg, M.; Brand, T.; et al. Health risk assessment of exposure to TriCresyl Phosphates (TCPs) in aircraft: A commentary. Neurotoxicology 2014, 45, 209–215. https://doi.org/10.1016/j.neuro.2014.08.011.
  • 39.
    Fries,; Sühring, R. The unusual suspects: Screening for persistent, mobile, and toxic plastic additives in plastic leachates. Environ. Pollut. 2023, 335, 122263. https://doi.org/10.1016/J.ENVPOL.2023.122263.
  • 40.
    Schymanski,L.; Singer, H.P.; Slobodnik, J. et al. Non-target screening with high-resolution mass spectrometry: Critical review using a collaborative trial on water analysis. Anal. Bioanal. Chem. 2015, 407, 6237–6255. https://doi.org/10.1007/s00216-015-8681-7.
  • 41.
    Safety Data Sheet: Skydrol PE-5 Hydraulic Fluid. 2023. Available online: https://ws.eastman.com/ProductCatalogApps/PageControllers/MSDSShow_PC.aspx (accessed on 27 July 2023).
  • 42.
    No-Bleed Systems: Saving Fuel and Enhancing Operational Efficiencies. 2008. Available online: https://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/article_02_2.html (accessed on 1 August 2023).
  • 43.
    OnlineAviation Training [OAT]. Boeing 787 General Familiarization—Potable Water 2023. Available online: https://oat.aero/2023/03/17/boeing-787-general-familiarisation-potable-water-onboard/ (accessed on 1 August 2023).
Share this article:
Download PDF
Supplementary Materials
DOI
10.53941/eccs.2025.100001
Issue
Volume 1, Issue 1
How to Cite
Hayes, K.; Megson, D.; Fries, E.; Sühring, R.; Roberts, G.; Doyle, A.; O’Sullivan, G. Hydraulic Oil Infiltration into Potable Water through Aircraft Pneumatic Systems: A Qualitative Assessment of Chemical Contamination. Environmental Contamination: Causes and Solutions 2025, 1 (1), 1. https://doi.org/10.53941/eccs.2025.100001.
RIS
BibTex
Copyright & License
article copyright Image
Copyright (c) 2025 by the authors.