How to Recognize and Respond to Fumes OnboardBasic Overview: Potential For Exposure To Oil/Hydraulic Fluid Fumes On Aircraft
Most aircraft are designed and operated to circulate cabin air through the aircraft engine. Engine oil and hydraulic fluid fumes can contaminate the ventilation air supplied to the cabin and flight deck. There are other aircraft air quality concerns, such as the cabin being too hot or too cold/drafty, stagnant ventilation zones, exposure to deicing fluid fumes, ozone gas, fuel fumes, and exhaust. But oil and hydraulic fluid fumes are especially toxic.
When oil or hydraulic fluid contaminates the air supply system, you will notice an unpleasant and unusual smell (“fumes”). Oil fumes are often described as smelling like “dirty socks,” or as being musty, moldy, or foul. Hydraulic fluid fumes often have a distinctive acrid odor. Both types of fumes can contain carbon monoxide gas. Exposure to carbon monoxide – especially inflight where the air contains less oxygen than on the ground – can cause acute symptoms like dizziness/fainting, headache, and slowed thought processes.
Oil fumes are a complex mixture of chemicals, including neurotoxic tricresyl phosphates and other toxins, some of which are listed on the product safety data sheets. Hydraulic fluid fumes are also a complex mixture of chemicals, including tributyl phosphates.
When the fumes contaminate the air supply system, you may see haze or smoke, but typically, you will “only” notice the odor. Still, it is important to recognize, respond to, and report the presence of these types of fumes in the air supply system because they can make you sick.
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https://www.afacwa.org/how_to_recognize_and_respond_to_fumes_onboard
Aerotoxic Syndrome, a new occupational disease
Aerotoxic syndrome: A new occupational disease caused by contaminated cabin air?
Abstract
The term aerotoxic syndrome has been proposed to describe a constellation of symptoms reported by pilots and cabin crew following exposure to possible (neuro)toxic substances in cabin air. Several organ systems are involved. Potentially toxic chemicals emanate from hydraulic fluids and engine oil and include organophosphate compounds, solvents and carbonmonoxide. Oil contamination in the compressor will result in nanoparticles in bleed air under most operating conditions. Overfilling of oil or faulty seals lead to oil leaks which permit ultrafine particles to cross oil seals. Extremely high temperatures in aircraft engines may alter the composition of the original oil and create new toxic compounds. De-icing fluids and the use of insecticides may also contaminate cabin air.
Regulatory authorities estimate fume events (incidental smells, smoke or mist inside an airplane) happen on 0.2–0.5% of flights. Objective evidence of exposure is often lacking and indirect proof in the form of biomarkers is scarce. The underlying mechanisms leading to chronic symptoms, extend beyond cholinesterase inhibition. Individual genetic differences in the ability to metabolize solvents and organophosphates may explain why long-term intermittent low-level exposure causes ill health in some people.
We discuss the current evidence for central nervous system injury in aerotoxic syndrome and propose diagnostic criteria to argue for its recognition as occupational disorder. Prospective studies and a proactive attitude of authorities are required. Nano-aerosols as vehicles for toxic compounds should stimulate the development of bleedless aircraft. Until then the “aircraft cabin of the future” should have continuous cabin air monitoring and filter technology to make flying safe for everyone.
Introduction
The term “aerotoxic syndrome” was proposed in 1999 by Balouet and Winder to describe a constellation of symptoms reported by pilots and cabin crew following exposure to hydraulic fluids, engine oil and pyrolysis products during flight (Balouet and Winder, 1999). Cabin air on most commercial aircraft is supplied from the engines or auxiliary power unit. Air is drawn from outside and then circulated around the engine where it is heated and pressurized to a breathable level before being “bled off” and pumped into the aircraft (see Fig. 1).
https://www.sciencedirect.com/science/article/abs/pii/S2468748022000017
Fume Event Now Considered “BIO HAZARD” In Canada
Cabin Air Quality and “Fume Events” Update Occupation Health and Safety – Newsletter #01 January 11, 2012
Fellow pilots,
Over time, the OHS Committees of ACPA have received progressively more reports and information related to “fumes events.” In view of the information available to us, we think that some clarification is required with respect to the following:
The possible sources of “fumes”; The contents of “fumes”; The potential health effects for pilots and other aircraft occupants exposed to fumes; andThe QRH checklists available to us and the importance of donning masks and landing ASAP as per the QRH when the situation warrants.
