CABIN AIR QUALITY AND TOXIC FUMES
Capt. Katia Defrancq
IFALPA
Presented by Dr. Ken Edgington
Abstract
The past few years, several serious incidents have been reported where pilots were incapacitated when fumes entered into the cockpit and/or cabin. From 1989 to 1999 there were 128 smoke and fumes reports on UK registered aircraft. These aircraft performed 2.85 million flights during that same period. Five types of aircraft from very different manufacturers were involved. Incidents occurred all around the world resulting a senate inquiry in Australia, Settlements in the USA and Australia and an investigation in Sweden.
The fumes are generally caused by engine oil or hydraulic fluid leaking into the air conditioning system. They cause a large spectrum of short to longer term symptoms ranging from dizziness and nausea to severe neurotoxicity problems. They present a real danger to the flight. Long-term problems have ended the careers of numerous pilots and flight attendants.
IFALPA wants to raise awareness in the aviation community, with the obligation for all parties to inform crews about the risks of fumes. We call for the introduction of a mandatory reporting system for fumes entering the cockpit or cabin. IFALPA further encourages the implementation of strict legislation on cabin air quality and systems design to prevent the problem and the introduction of support to the victims of toxic fumes.
Introduction
1989 – A F100 experienced fumes and smoke in the cabin. The cabin crew members experienced severe headache, loss of balance and nausea, the co-pilot reported feeling ‘drunk’ with weak legs and a generalized feeling of fatigue.
1997 – A Bae 146 was about 1 hour in flight when the crew and passengers noticed a smell of engine contamination in the air. The flight crew suffered eye redness and lacrimation. The Captain’s symptoms worsened causing nausea, vestibular problems, tunnel vision, headaches and sore eyes. Since, this pilot suffers of headaches and head pressure, weakness, chronic fatigue, concentration and memory difficulties and other neurotoxic symptoms making it impossible for her to pass a medical test for flying license while she continuous suffering the many symptoms.
1999 – Bae 146 - It started with an insidious feeling of discomfort. The cabin attendants felt strange, experiencing an incredible pressure in their heads and bodies. One person described the feeling as like doing a “moonwalk”. Another person detected a barely perceptible odor. On the next flight, the discomfort returned and was now also experienced by the two pilots. During the third flight, the crew realized that there was something unusual in the air inside the airplane. And when the cabin manager went into the cockpit prior to landing, she discovered that both the pilots were wearing their oxygen masks. The captain felt so bad that he had handed over the controls for his first officer to land the plane.
MSDS excerpt for one widely used aircraft fuid :
INGESTION:
Because of its low viscosity, this material can
directly enter the lungs, if swallowed,
or if subsequently vomited. Once in the lungs it is very difficult to remove and can cause severe
injury or death.
INHALATION:
Excessive or prolonged breathing of this material may
cause central
nervous system effects. Contains a petroleum-based mineral oil. May cause respiratory irritation or other pulmonary
effects following prolonged or repeated inhalation of oil mist at airborne levels above the
recommended mineral oil mist exposure
limit.
SIGNS AND SYMPTOMS OF EXPOSURE:
Skin irritation: may include pain, reddening,
swelling, and blistering.
Central nervous system effects may include headache, dizziness, nausea,
vomiting, weakness, loss of coordination, blurred vision, drowsiness,
confusion, or disorientation. At extreme exposures, central nervous
system effects may include respiratory depression, tremors or convulsions, loss of consciousness, coma or death.
Airborne Chemicals
Airborne Chemicals refer to chemical contaminants in gas and aerosol (liquid or particulate) phases. Aircraft fluids include de-icing fluids, lubricating oil for engines and APU, jet fuel, coolants and fire fighting fluids.
Contamination by aircraft fluids can come from aircraft generated contaminants such as smoke from engine fires, seal failure, wear and aging, de-icing, pack burnout procedures, residual contamination from lack of cleaning after contamination events. It can also be generated in-cabin by aircraft compounds – offgasing due to paints and coatings – or service compounds such as cleaning fluids and insecticides.
Among trace chemicals are compounds of identified toxicity
Jet oils are specialized synthetic oil used in high performance jet engines. They have an appreciable hazard based on toxic ingredients, but are safe in use provided that maintenance personnel follow appropriate safety precautions and the oil stays in the engine. Aircraft engines that leak oil may expose others through uncontrolled exposure. Toxic products, such as TCP (tricresyl phosphate) were continued to be used as an additive despite their acknowledged toxicity..
In jet oil, TCP is used in the formulation of lubricants as an anti-wear additive to enhance load bearing properties and improve tolerance to increasing speed of rotating or sliding motion. It also is also claimed for flame retardant properties. While some other triaryl phosphates have similar properties and may also be used as oil additives, the anti-wear properties of TCP have been considered unique.
Since 1899 the neurotoxicity of organophosphates is known.
Inhibition of neurotoxic esterases
(NTE) can lead to neuropathological , neuropsychological conditions, wether
acute or chronic, leading to short term versus long term adverse health
effects.
Symptoms
A large variety of symptoms have been noted. Some were merely a nuisance, other incapacited flight crews. Long term symptoms have ended the careers of several flight and cabin crew members.
Symptoms from single or short-term exposures include:
· neurotoxic symptoms: blurred or tunnel vision, nystagmus, disorientation, shaking and tremors, loss of balance and vertigo, seizures, loss of consciousness, parathesias;
· neuropsychological symptoms: memory impairment, headache, light-headedness, dizziness, confusion and feeling intoxicated;
· gastro-intestinal symptoms: nausea, vomiting;
· respiratory symptoms: cough, breathing difficulties (shortness of breath), tightness in chest, respiratory failure requiring oxygen;
· cardiovascular symptoms: increased heart rate and palpitations;
· irritation of eyes, nose and upper airways.
· Neurotoxicity is a major flight safety concern, especially where exposures are intense.
Symptoms from long term low-level exposure or residual symptoms from exposure events include:
·
neurotoxic symptoms: numbness (fingers,
lips, limbs), parathesias;
·
neuropsychological symptoms: memory
impairment, forgetfulness, lack of co-ordination, severe headaches, dizziness,
sleep disorders;
·
gastro-intestinal symptoms: salivation,
nausea, vomiting, diarrhoea;
·
respiratory symptoms: breathing difficulties (shortness of
breath), tightness in chest, respiratory failure, susceptibility to upper
respiratory tract infections;
·
cardiovascular symptoms: chest pain, increased heart rate and
palpitations;
·
skin symptoms: skin itching, rashes, skin
blisters (on uncovered body parts), hair loss;
·
irritation of eyes, nose and upper
airways;
·
sensitivity: signs of immunosupression,
chemical sensitivity leading to acquired or multiple chemical sensitivity
·
general: weakness and fatigue (leading to
chronic fatigue), exhaustion, hot flashes, joint pain, muscle weakness and
pain.
(table reproduced from Balouet JC and Winder C)
Regulations
JAR
25.831 Ventilation
Date: October 1, 2000
(a)
Each passenger and crew compartment must be ventilated and each crew
compartment must have enough fresh air (but not less than 10 cubic ft per
minute per crew member) to enable crew members to perform their duties without
undue discomfort or fatigue. (See ACJ 25.831(a).)
(b)
Crew and passenger compartment air must be free from harmful or hazardous
concentrations of gases or vapors. In meeting this requirement, the following
apply:
(1) Carbon monoxide
concentrations in excess of one part in 20 000 parts of air are considered
hazardous. For test purposes, any acceptable carbon monoxide detection method
may be used.
(2) Carbon dioxide in excess
of 3% by volume (sea-level equivalent) is considered hazardous in the case of
crew members. Higher concentrations of carbon dioxide may be allowed in crew
compartments if appropriate protective breathing equipment is available.
(c) There must be provisions made to ensure that the conditions prescribed in sub-paragraph (b) of this paragraph are met after reasonably probable failures or malfunctioning of the ventilating, heating, pressurization or other systems and equipment. (See ACJ 25.831 (c).)
Ozone concentrations are not regulated in the JARs.
The lack of proper regulations and the sometimes-contradictory industry standards need to be addressed urgently. Where as reactive measures civil aviation aircrew worldwide have filed over 130 lawsuits and substantial settlements have been paid, it is time to think about prevention.
Dr. Claus Curdt Christiansen had officially proposed the establishment of a Cabin Air Quality Working Group in 1996. Being the heart of International Civil Aviation it would be the proper place to address these issue. Its task should consist of reviewing research, setting up a mandatory reporting system for smoke and fumes occurrences and proposing Standards and Recommended Practices.
Recommendations
Are to :
Conclusions
IFALPA hopes for an increased awareness among crews and medical staff concerning the risks to crews and actions to be taken.
Mandatory reporting systems for smoke and fumes incidents should help getting a better insight in the number of occurrences and improve the possibilities of research into the effects of exposure. Occurrences which should be reported are smoke, haze, fumes and odors in the cabin or flight deck, leak events discovered by checking on the tarmac, by gauge – top up needed – and mechanical problems such as seal failure or wear. Crew and passenger physiological complaints should also be reported.
Actions after incident reports should include the check of maintenance records and logs, before and after the incident, pilots reports should be checked versus engineers reports and all information on incidents should be brought together with the purpose of further analysis and research.
All Authorities should adopt regulation of cabin environment, including airborne and even trace chemicals.
Crews who suffered exposure must be given appropriate support and medical care. Standard medical protocol to test the exposed crew should be included in the regulations.
Further research should be conducted to investigate the long term effects of these occurrences on the health of crews and passengers.
ICAO or WHO are viewed as proper bodies to incorporate a Cabin Air Quality Working Group, preparing Standards and Recommended Practices and following the set-up of a mandatory reporting system
Annex 1: Recommendations by the Australian Senate Committee
(a)
The Committee recommends that CASA should reassess matters recommended
for further action by the BASI/ATSB incident report (No. 199702276) concerning
the incident on 10 July 1997 involving Captain Kolver.
(b)
The Committee also recommends that CASA reassess its requirements for
monitoring the operations and cabin and cockpit air quality of the BAe 146
aircraft operating in Australia and, where necessary, introduce regulations
under the Civil Aviation Act 1988 specifying:
·
a specific national
standard for checking and monitoring the engine seals and air quality in all
passenger commercial jet aircraft;
·
maintenance procedures
(including specific maintenance procedures for ageing aircraft);
·
specific, appropriate
maintenance and operational procedures for the BAe 146 which pay particular
attention to the need to ensure aircraft are withdrawn from operational flying
and serviced to ensure any operating faults resulting in oil leaks, fumes or
smoke are immediately repaired;
·
that incident reports
should now be specifically designed so as to reflect the history of the cabin
air problem that has been encountered on the BAe 146;
·
sources of contamination
in the cabin and cockpit environment in the BAe 146 be identified and further
evaluated using appropriate sampling and analytical technology for the
contaminants which, for example, might result from the burning of lubricating
oil used in the BAe 146 engines;
·
companies operating BAe
146 and other passenger commercial jet aircraft in Australia provide CASA with
specific reports on the results of monitoring these matters within an
appropriate timeframe, whether quarterly or six-monthly, in order that CASA can
assess the operations of the aircraft; and
·
air quality monitoring
and compulsory reporting guidelines for all passenger jet aircraft operators.
The Committee recommends that CASA adopt the modification to aircraft
air circulation systems proposal for the BAe 146 aircraft by the aircraft’s
manufacturer as compulsory for all BAe 146 operating in Australia and that this
be achieved by preparation and issue by CASA of an appropriate form of
maintenance direction under the Civil Aviation Regulations.
The Committee also recommends that registration of BAe 146 aircraft
operating in Australia be reviewed, and that renewal of Air Operating
Certificates and registration of the BAe 146 be subject to completion of those
recommended modifications as a condition for continued registration of the
aircraft.
The Committee believes that development of an appropriate and accurate test for the presence of any chemical fumes in aircraft cabins is essential. The Committee accordingly recommends that CASA liaise with operators to develop a standardized, compulsory monitoring program, which provides for testing cabin aircraft air during fume events.
The Committee recommends that the Minister for Transport request the
Strategic Research Development Committee of the National Health and Medical
Research Council to set up and undertake an appropriate research program on the
effect of exposure to aircraft cabin air on air crew and passengers. The
Committee also recommends that the Minister advise the Parliament on the form
and duration of, such a program as part of the Government response to this
report.
While the Committee is aware that the cases referred to are a matter of
state jurisdiction, the Committee recommends that the Minister for Transport,
in co-operation with appropriate State Ministers, appoint an experienced,
retired judicial officer or eminent person who is appropriately qualified to
conduct a review of unsuccessful or inordinately delayed employees’
compensation cases, pilots’ loss of license insurance, personal income
protection, and with-held superannuation/other insurance claims made for
personal injury and loss of employment as a result of ill health claimed to
result from exposure to fumes on the BAe 146 and other aircraft. That person
should be asked to report to the Minister on any conclusions they reach and
whether those cases were dealt with according to requirements and appropriate
standards of procedural fairness.
The Committee also recommends that the Minister table the conclusions
and any recommendations it makes in the Parliament.
The Committee also recommends that the potentially hazardous chemical
components of Mobil Jet Oil II be referred to NICNAS as a priority for review
and assessment.
Chairman
This text is a summary of research results I found in related literature. Most information is coming from Professors Balouet and Winder, whose work is invaluable in increasing awareness and knowledge in the field of Cabin Air quality..
All used references are listed below