Pressure Points
Clearing the air
10 Spray April 2018
Steve Bennett, PhD
VP, Scientific Affairs, HCPA
A recent study published in the journal Science runs
counter to much of the current scientific understanding
of volatile organic compound (VOC) impact on air
quality. However, evaluating new information, its credibility
and the claims put forward are a fundamental part of being a
critical thinker—whether you are a consumer choosing between
two new products or a scientist evaluating a new study. That’s
why we are all taught the basics of the scientific method in
grade school and why I expect rigorous scientific reasoning
from myself and my colleagues.
The new study, entitled “Volatile Chemical Products Emerging
as Largest Petrochemical Source of Urban Organic Emissions” by
McDonald et al., purports that current VOC inventories and
models underestimate the portion of consumer product-related
VOC emissions and that emphasis on ozone reductions to
achieve better air quality may need to be revisited.
When it comes to sources of man-made air pollution, mobile
sources (cars, trucks, etc.) have been one of the largest pieces
of the pie for more than 30 years. That is why they have been
highly regulated—with great success.
With the significant decrease in emissions from mobile
sources, it is not surprising
that other sources of emissions
would become more
significant in the total emission
inventory. When one
piece of a pie shrinks, the
others look bigger in comparison.
However, in this
VOC emissions from consumer products
have dramatically decreased due to
tighter regulations and innovation
within the industry.
case, it should not be lost
that the pie as a whole has
also gotten smaller—other
categories of emissions have also been regulated and reduced.
VOC emissions from consumer products have dramatically
decreased due to tighter regulations and innovation within the
industry. HCPA member companies have invested hundreds
of millions of dollars to develop new or reformulated products
with lower amounts of VOCs, thereby lessening the impact on
air quality. The efforts driven by both regulators and industry
have resulted in an overall 50% reduction in the VOC
emissions attributed to consumer products, with even greater
reductions in certain product categories nationwide, especially
in California.
HCPA’s initial review of the McDonald et al. study highlights
several concerns with their modeling and conclusions, such as:
• Use of 1990 national data on consumer products to model
2012 emissions without considering the significant changes
consumer product formulations have undergone in that
period
• Utilization of aerial monitoring measurements conducted
during the summer in Pasadena and applying them
throughout the rest of California and the entire U.S.
• Assignment of VOCs exclusively to consumer products
without considering other emission sources
• Choice of surrogate when working on something as complex
and specific as photochemical reactivity, which likely overestimated
the degree of impact.
All of this isn’t to say that the study is based on “bad science.”
It can be hard to accept new information when it contradicts
what we previously thought, however science which goes against
the last 30 years of our understanding needs to be scrutinized.
Appropriately, the study identifies the need for further investigation,
for example, an improved understanding of photochemical
reactivity and secondary organic aerosol (SOA) formation, not
only with VOCs, but also low vapor pressure volatile organic
compounds (LVP-VOCs).
It will be highly instructive to compare the comprehensive
and definitive California Air Resource Board (CARB) Consumer
Product Survey data of more than 400 categories of consumer
products that were sold in California during 2013–2015 leading
to emissions identified in this study. This will help all of us
determine what, if any, future
adjustments to existing or
new regulations are necessary
to achieve an even better air
quality. Pursuing additional
research will better clarify the
concerns HCPA and others
have identified and move
the scientific understanding
forward.
For more than 30 years,
HCPA and our member companies
have worked collaboratively with legislators, regulators,
non-governmental organization (NGOs) and stakeholders at all
levels of government to significantly improve air quality in California
and across the U.S. Since 1989, HCPA, building upon a
strong scientific foundation, has actively engaged in negotiating
provisions of every one of the numerous rulemaking procedures
CARB has conducted to continually tighten California’s
comprehensive and stringent consumer products regulations.
This has led to a tremendous improvement in the air quality
for all Californians. HCPA members also worked with the U.S.
Environmental Protection Agency (EPA) to develop the current
national VOC regulation for consumer products. Further,
HCPA member companies worked with the Ozone Transport
Commission (OTC) to develop the Consumer Products Model
Rule, which has been adopted in 16 states and the District of
Columbia.
HCPA and its members remain committed to providing
sustainable products that achieve rigorous emissions standards
while helping consumers and workers live cleaner, healthier and
more productive lives. Please contact me at sbennett@thehcpa.
org if you would like to learn more about our efforts. Spray