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Goodyear keeps a pulse on global issues relating to the environment, health and safety of customers, associates and communities in which the company operates. Many times, the company takes sides on particular issues that are in the news or that face government scrutiny. For 2003, these Hot Topics include low-rolling-resistance tires, aromatic oils and tire wear particles.
To access these topics, either click on the following or scroll to find the articles:
Low-rolling-resistance Tires
Low-rolling-resistance tires normally are used as original equipment on many vehicles to help auto manufacturers meet federal corporate average fuel efficiency (CAFE) standards. These U.S. mileage standards were adopted to reduce the use of fossil fuels and to improve the environment.
Some people have suggested that low-rolling-resistance tires should be adopted as the standard for all tires. However, low-rolling-resistance tires have a shorter life and are more expensive to manufacture than current replacement tires. We believe a full understanding of tire design trade-offs, life cycle impacts and higher cost is necessary.
Tire design
Tire design is based on balancing competing and conflicting objectives for each tire. The major objectives include wet and dry traction, ice and snow, ride, treadwear, rolling resistance and cost. Different tires are designed for different customers based on the characteristics they value most. Tradeoffs must be made to maximize any single characteristic.
Customers are familiar with these issues as they frequently hear advertising and base purchasing decisions on tire performance characteristics (snow and ice tires, wet weather tires, tires with premium ride and tires with long wear). Low-rolling-resistance tires can have reduced treadwear, less traction and higher costs than conventional replacement tires.
Life cycle impacts
Goodyear believes its products should be evaluated according to environmental impacts relating to materials used in their manufacture, the manufacturing process, their use and their disposal.
Because low-rolling-resistance tires have a shorter life, more new tires
and more raw materials will be required to provide tires for the same
vehicle miles. Low-rolling-resistance tires also produce more emissions
during manufacture. And a shorter tire life ensures that more scrap tires
will be produced. Opinions on low-rolling-resistance tires have focused
on their fuel economy benefits without consideration for other phases
in life cycle.
Economic Impacts
Economic analyses have focused on fuel cost savings, yet no detailed analysis has factored in higher manufacturing costs and shorter tire life. In addition, no definitive analysis has been conducted of other alternatives. For example, proper tire inflation maintenance is a low-cost alternative for improved rolling resistance and tire life.
The Rubber Manufacturers' Association's "Be Tire Smart, Play your PART" program is designed to raise consumer awareness and improve tire performance.
Conclusions
There are currently inadequate environmental or economic data to support
legislative requirements that all tires be low rolling resistance. In
fact, legislating low-rolling-resistance tires is expected to have a detrimental
effect on tire life cycle due to tradeoffs required to achieve low rolling
resistance. Consumers would be expected to pay more for tires that provide
less performance in other areas they consider important long life and
traction.
Goodyear supports programs to research and test alternatives to determine the best life cycle and best economic solution. Until comprehensive studies addressing the entire life cycle of a tire have been considered and that data demonstrate the advantages of making all tires low rolling resistance, Goodyear will continue to provide a wide range of options for its customers.
Highly Aromatic Oils in Tires
Current scientific data does not support legislation or regulations to
restrict the manufacture or marketing of tires with highly aromatic oils
containing polynuclear aromatic hydrocarbons (PAHs). In addition, aromatic
oils when incorporated into rubber or into tires do not pose health risks
to humans, and their release into the environment is negligible.
It is recognized and supported that the emission of carcinogenic substances
into the environment should be as low as possible to control any risks
to human health and the environment. Existing research data indicate that
during tire manufacture, exposure to aromatic oils is minimal to zero.
Chemical analysis has been unable to detect any PAH release into the environment
from tire debris.
Several reports pertaining to aromatic oils, including from the International Agency for Research on Cancer, point to other environmental sources of PAH, such as asphalt run-off, auto emissions, polluted air, cooking, wood smoke, and tobacco smoke among other sources. The Swedish National Chemicals Inspectorate report (June 1994) alludes to an environmental contribution, but is based solely on inaccurate theoretical assumptions and calculations.
Human risk?
The risk for high levels of PAHs in highly aromatic oils is the potential for skin cancer to develop in workers exposed to oils, with prolonged and repeated skin contact, where good hygiene is not practiced. In the rubber industry where aromatic oils are used as process and extender oils, the incidence of skin cancer has not been increased by the handling of oils during the manufacturing processes. The rubber manufacturing industry has taken measures to eliminate exposure risk during handling by the installation of enclosed systems.
Ratpan and Hayes (1989) performed animal skin-painting studies with polymers containing highly aromatic oils. No skin cancer developed during the 18 months of study. Also, there is no reported incidence of human skin cancer from exposure to these types of oil-containing polymers. Using laboratory tests (Ames in-vitro assays) similar to those tests used to help determine the carcinogenic potential of highly aromatic oils, organic extracts of tire wear debris did not show any mutagenic activity (Hannigan, 1994).
Environmental risk?
Current scientific knowledge indicates that zero to negligible PAHs are emitted into the environment from tire wear particulates as a consequence of tire tread abrasion. There is no reliable environmental scientific justification for prohibiting the use of highly aromatic oils in tires.
The "University of Dortmund, Baumann/Ismeier, Institute for Environmental Research" research project paper (1997) indicates that PAHs are not released or at the most negligibly released from tire abradate (debris). This study was performed under contract from the German Federal Office of the Environment.
L'Institut Pasteur conducted inhibition, mobility and mortality tests in 1996 following European Union protocols. The tests, using rubber powder buffed from passenger tire treads, indicated extremely low levels of aquatic toxicity for water leachate. Thus, the leachate material is not considered toxic to aquatic organisms.
Safety considerations
Tires are a key component in automotive safety. Tires enable the driver
to safely accelerate, maneuver, and stop under a wide range of speeds,
surface conditions and weather, while providing ride comfort and long
wear. Highly aromatic oils contribute directly to tire performance, integrity
and traction. These oils, therefore, play a critical part in tire quality
and the safety of all users and passengers in motor vehicles.
Because tire integrity and the safety of the end user are paramount, it is essential that any mass change in oil or any critical component not be undertaken until a full and thorough evaluation is complete, and that safety has been fully demonstrated.
Tire technology issues
Numerous materials are blended with natural and synthetic rubber to make rubber tire components. The various components are used to form and construct a tire. The tire is then cured under high temperature to produce the final composite thermoset finished tires.
Goodyear is committed to producing new types of tire lines. Hundreds of Goodyear engineers and scientists constantly evaluate new materials and new combinations of old materials. Goodyear continually works to develop new tires that meet constantly increasing customer requirements and expectations, while decreasing the impact on the environment.
Goodyear continues to explore the use of low-aromatic oils and other
substitute materials. When product performance criteria are satisfactorily
achieved, all safety considerations are addressed, product quality is
assured and life cycle issues finalized. Use of replacement oils then
can commence.
Conclusions
It can be concluded that rubber tires contain PAHs originating from certain oils used in tire manufacturing, but there is clear scientific evidence that any release into the environment is negligible relative to other PAH sources. The European Commission's Scientific Committee on Toxicity, Ecotoxicity and the Environment (CSTEE) supports this conclusion.
The CSTEE states that, "a reduction of the concentration of PAHs in tyres
will insignificantly reduce the overall concentration of PAHs in the environment."
[Brussels, C7/GF/csteeop/PAHs/12-121103 D(03)]. The CSTEE adopted the
risk assessment for PAHs in extender oils and tires in its plenary meeting
of 12-13 November 2003.
It also has been demonstrated that the risk of rubber workers developing skin cancer from exposure to highly aromatic oils contained in rubber is non-existent. Therefore, there is no scientifically based need to restrict the use of highly aromatic extender oils to produce tires.
Furthermore, it is Goodyear's Environmental Health & Safety policy to ensure our products are safe by using materials that will not cause harm to our workers or the environment. It is also our policy to comply with our global environmental, health, and safety standards and the laws of each country where Goodyear does business.
Tire wear particles
Goodyear has analyzed the published literature on the concerns to health
and the environment produced by tire particulate emissions. Based on the
published data and evaluations, Goodyear concludes that wear and abrade (coarse particles greater than 93 percent, fine
particles less than 7 percent). The rate of treadwear is influenced
by many variables, including the type of tire produced, roadway characteristics
and driving styles.
Studies conducted by Blok, l'Institut Pasteur and other investigators
indicate that tire debris and fine airborne tire dust resulting from tire
wear pose no significant environmental issues. Tire wear is a minor source
of particulate matter, compared with tailpipe and road dust, and contributes
1.1 percent or less of the PM10 and PM2.5 from all sources in the European
Union-15 countries (CEPMEIP, 2001).
Epidemiological studies conducted by the Health Effects Institute,
the World Health Organization and other investigators do not implicate
tire wear particles in ambient air as contributing to human health effects
(respiratory and cardiovascular diseases).
Organic pollutants, including polycyclic aromatic hydrocarbons (PAHs)
found in road dust and in airborne particulate matter, are derived primarily
from vehicle exhaust and stationary combustion sources. Scientific data
do not indicate that PAHs are released into the environment from tire
debris.
Tire debris is found in diffuse roadside soils, but the published
studies present no evidence for ecotoxic effects in or from roadside
soil. Also, tire wear debris in roadside soils is degraded by bacteria
and fungi and/or decomposed by oxygen and sunlight.
There are no definitive data to associate road runoff leachate with
adverse effects on aquatic ecosystems.
The hypothesis that extractable dry natural rubber protein causes
allergic reactions or contributes to asthmatic conditions has been refuted
with scientific data.
Conclusion
Based on all available scientific data, Goodyear concludes that tire wear particles pose no environmental concerns.
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