Pavement Preservation Journal - Summer 2015 - (Page 39)
New Cold Milling Rules will
Reduce Respirable Silica
By Tom Kuennen
IMAGE CREDIT: TOM KuENNEN
t World of Asphalt/AGG1 2015 in March in
Baltimore, the road maintenance and pavement
preservation community celebrated the release
of new industry cold milling guidelines that
will provide a reduction in airborne silica particles in the
work zone, while forestalling onerous industry regulations.
The new guidelines, released in March - Best Practice
Engineering Control Guidelines to Control Worker Exposure to
Respirable Crystalline Silica during Asphalt Pavement Milling -
are the result of a collaboration between federal worker
safety agencies, national associations and labor unions, and
cold milling equipment manufacturers.
Available as DHHS (NIOSH) Publication No. 2015-105,
the document represents more than 10 years of
collaborative research by labor, industry and government to
reduce respirable crystalline silica exposure during asphalt
pavement milling in highway construction.
The collaborative research began when the Silica/Asphalt
Milling Machine Partnership was formed at the 2003
National Asphalt Pavement Association annual meeting,
and studies on milling machine dust controls began later
At World of Asphalt/AGG1 2015 observance, National Asphalt Pavement
Association president Mike Acott recounts the challenges - and public/
private collaboration - involved in developing new manufacturer guidelines
to reduce respirable crystalline silica in asphalt cold milling operations
NIOSH recommends the use of ventilation controls to
control worker exposures to respirable crystalline silica
during asphalt pavement milling in highway construction.
The ventilation controls used in combination with
water-sprays that cool the cutting teeth can consistently
reduce exposures below the NIOSH recommended
exposure limit of 0.05 mg/m3.
The partnership conducted considerable research to
develop best practice recommendations for water-spray
dust suppression on asphalt milling machines.
NIOSH recommends using best practice water-spray
systems on asphalt milling machines that do not have
Two effective dust control methods utilizing water sprays
that are readily applicable to asphalt pavement milling
operations are dust prevention and suppression techniques,
the guidelines say. First, dust prevention is achieved by
spraying water onto the pavement being milled in order
to prevent dust from being liberated or generated and
The second method, dust suppression, involves knocking
down airborne dust by spraying the dust cloud and causing
the particles to collide, agglomerate, and fall from the air.
A common and effective practice is to use a combination of
both of these wet methods in the overall dust control plan.
As water is used on all asphalt pavement-milling machines
to cool the cutter bits, it is logical to also use this water for
respirable dust control.
The complete report and associated spreadsheet are
available for download. Visit http:/
docs/2015-105/ for your copies.
pavement preservation journal
Table of Contents for the Digital Edition of Pavement Preservation Journal - Summer 2015
Pavement Preservation World Convenes at PPRS Paris 2015
PPRS Paris: ARRA, AEMA and ISSA Meet at Same Venue
Superior Program Earns FP2 Award for Charleston County
Focus on Preservation at NCAT Pavement Test Track Meeting
Preservation Paramount at Record World of Asphalt
Under Traffic, Rejuvenating Fog Seal Preserves I-475
New Cold Milling Rules will Reduce Respirable Silica
Revised Recycling Manual Now Available from ARRA
San Diego County Preservation Work Wins ISSA’s Top Award
Report: Enhancer Provides Antistrip Performance in Adverse Conditions
Index of Advertisers
Pavement Preservation Journal - Summer 2015