DIMETHYL CARBONATE
(DMC)
The Newest VOC Exempt
Solvent
Kowa American Corp
October 2011
Previous VOC Exempt Coating
Solvents
• Realistically there were only a handful of VOC
exempt solvents that are not HAPS (or ODS)
and under $ 2.00/lb that formulators can use for
coating, cleaning & adhesive solvents:
• Acetone
• Methyl acetate (MeAc)
• tert-Butyl Acetate (tBAc)
• p-Chlorobenzotrifluoride (PCBTF)
Dimethyl Carbonate (DMC)
• VOC exemption petition filed July 2004 by
Kowa American Corp.
• DMC has perhaps lowest MIR value of any
liquid chemical in commercial use based on
studies conducted by Dr. William Carter
(study funded by Exxon Mobil Chemical)
• Ultra-low MIR is allowing for fast
approvals by the various states due to its
very favorable ozone reduction potential
DMC & PC recently exempted
by the EPA
• Dimethyl Carbonate (DMC) & Propylene
Carbonate exempted by EPA on Jan 13, 2009
• Each state must also exempt DMC & PC for
stationary source VOC rules.
• Almost all states beside California will have
exempted DMC by mid 2012 (45 states have
now exempted DMC (Oct. 2011)).
• California must have each of their Air Districts
separately exempt DMC for coatings, Inks and
adhesives, which is proceeding forward.
DMC for Architectural, Aerosol
& Automotive Refinish Coatings
• DMC is VOC exempt in all states today
except for Mass. & parts of California for:
Architectural Coatings (subpart D),
Automotive Refinish Coatings (Subpart B)
and Consumer Items (subpart C) based on
Federal VOC rules (40 CFR part 59)
• DMC (with its ultra low MIR value) can be
used in aerosol coatings in Calif. (soon to be
approved for all of USA for aerosol coatings).
DMC VOC Exempt States
Washington
March 2011
Montana
Oregon
May 2010
Vermont
New Hampshire
Wisconsin
August 2010
South Dakota
June 2010
Nebraska
June 2010
Utah
March 2010
California
Each AMD
must exempt
New
Mexico
Kansas
Sept. 2010
Oklahoma
July 2010
Indiana
Texas
April 1, 2010
New Jersey
Ohio
West
Virginia
Virginia
Delaware
Maryland
Kentucky
Tennessee
August 2010
North Carolina
Arkansas
Alabama
March
2010
Alaska
Dec. 2010
Massachusetts
Rhode Island Sept. 2010
Connecticut
Pennsylvania
Iowa
Missouri
Dec. 2010
New York
Dec 2010
Michigan
Illinois
Colorado
Arizona
Maine
Minnesota
Idaho
March 2010
Wyoming
Oct. 2010
Nevada
North Dakota
South Carolina
Nov. 2010
Georgia
Louisiana
Florida
Hawaii
Green states
are VOC
Exempt
DMC Exemption Status in Calif.
• San Diego, Santa Barbara, Monterey Bay,
Mohave, Butte ,Ventura, Colusa, Antelope
Valley & Feather River AMD’s have exempted
DMC as a VOC with no restrictions on use.
• There are no VOC rules in most northern and
mountain AMD’s (DMC functionally exempt)
• Shasta, Glenn, El Dorado, Tehema & San Luis
Obispo AMD’s may require a variance for
some stationary sources, most architectural
uses do not have VOC rules.
• Santa Barbara users must file for a permit
DMC Exemption Status in Calif.
• Bay Area AQMD (San Francisco area) is
drafting a rule exempting DMC for late 2011
public comment, early 2012 exemption
• SCAQMD (L.A. area) has proposed DMC as
VOC exempt in coating of metal parts
according their rule 1107, individual permits
would be required, early 2012 target date,
other uses to be examined after this approval.
• San Joaquin Valley, Imperial and Sacramento
AMD’s expect to exempt by end of 2011
Del
Norte
Siskiyou
Shasta
Trinity
Green = DMC VOC Exempt or
Functionally Exempt/ no VOC rules
(no restrictions on use of DMC)
Modoc
Lassen
Tehama
Butte
Glenn
Light Green = permit or an
individual variance may be needed
Plumas
Sierra
Nevada
Colusa
Lake
El Dorado
Yolo
Alpine
Napa
Amador
Sonoma
Solano
Marin
San
Contra Joaquin
Tuolumne
Costa
San Francisco
Light Blue = In rulemaking or
preparing rule or partial rule
Tan = no formal rulemaking yet
Mono
Alameda
San
Mateo
Santa
Santa
Clara
Merced
Cruz
San
Benito
Fresno
Inyo
Tulare
Monterey
Kings
San Luis
Obispo
Kern
San Bernardino
Santa
Barbara
Los
Ventura Angeles
Orange
Riverside
San Diego
Imperial
California CARB Consumer items
• CARB regulates “consumer product” applications
(coatings are covered by each AQMD separately)
• Paint thinners is in their “multi-purpose solvent”
classification (some local Calif. AMD’s debate
that CARB can regulate paint thinners over them)
• CARB needs typical formulations for non-coating
consumer applications using DMC, including the
solvent the DMC will replace for CARB to do a
health hazard assessment. CARB Contact: Carla
Takemoto 916-324-8028, ctakemoto@arb.ca.gov
MIR Reactivity Values (2009)
MIR gram basis MIR mole basis
DMC
0.055
4.95
Ethane
0.26
7.8
Acetone
0.35
20.3
Methyl Acetate
0.067
5.2
Prop Carbonate
0.27
27.56
Benzotrifluoride
0.28
40.91
DMC General Properties
• DMC is a colorless, fast evaporating solvent
• Has substantial polar nature, and moderate hbonding strength effective in replacing esters,
glycol ethers and ketones in formulations
• Has low toxicity, an unobjectionable
methanol type odor and low skin irritation
• Freezes at 2 – 4 ºC (36 –38 ºF)
• Flammable Liquid, Flash point 17 ºC (63 ºF)
DMC Structure
O
CH 3
O
C
O
CH 3
DMC Evaporation Rate
Fast to moderate evaporation rate (3.22 –
3.4, BuAC = 1.0), similar to tBAC (2.8),
toluene (2.0) and isopropyl acetate (3.0)
Can be used to as slightly slower
evaporating replacement for MEK (3.8),
Ethyl Acetate (4.1- 4.2), or as faster
evaporating replacement for IPA (1.7),
MPK (2.3), Ethanol (1.8) and MIBK (1.6)
DMC - Flammability
• DMC has a flashpoint of 63ºF (17ºC)
• Flammability will limit use in consumer
coatings, cleaning or indoor applications
• Flammability risk still much lower than
acetone (-4º F), ethyl acetate (26ºF) or MEK
(26ºF), which DMC can readily replace
• Partially water soluble (up to 13 % in
water), which allows water to be more
effective in fighting DMC based fires.
Flashpoint, E. rate, Boiling point
Evaporation Flashpoint
Rate
ºF
BuAc =1.0
Boiling
point ºC
DMC
3.22
63
90
PCBTF
.9
109*
139
Acetone
5.6
-4
56.5
<.005
269.6
240
Prop Carb
tBAc
2.8
40
98
BTF
2.8
54
102
DMC Solubility Properties
• Hildebrand solubility parameter 20.3 Mpa
• Hansen solubility parameters: Dispersion
15.5 polar 3.9 h-bond 9.7 molar vol. 84.2
• Similar solubility parameters to some
common glycol ethers: cellosolve acetate,
ethylene glycol butyl ether acetate,
propylene glycol monobutyl ether and
propylene glycol monoethyl ether acetate
DMC Solubility Properties
DMC has been described as useful in acrylics,
urethanes, epoxies and alkyd systems.
DMC is miscible with almost all organic
solvents
DMC would easily replace oxygenated
solvents like esters, ketones & glycol ethers
DMC can replace alcohols, aromatics and
aliphatics with appropriate co-solvents
and/or reformulation work
DMC in Waterborne Systems
• DMC being an ester, can hydrolyze in
acidic and basic conditions to methanol and
carbon dioxide.
• DMC may be stable in neutral conditions
with suitable buffers, although formulators
need proper care to prevent CO2 build up
• DMC’s primary usage area should be in all
solvent borne systems, where residual water
does not normally cause hydrolysis issues
DMC Expected Uses
• DMC has shown promise in Auto refinish,
with its favorable solubility, odor,
evaporation rate and economic profiles
• Industrial coatings for coating parts and
architectural components at factories have
shown similar appeal.
• Also used in traffic paints, steel drum
linings, floor coatings, concrete sealers
• Can also be an effective paint thinner &
multipurpose solvent, as is or as co-solvent
DMC’s Odor Profile
• One of DMC’s most favorable properties is
a mild and non-offensive odor.
• PCBTF and Tert-Butyl Acetate odors are
much more pronounced and pungent
• Noxious solvent odors are perhaps the most
important concern of neighbors to body
shops, factories, print shops and other
industrial settings
• Mild odor is well received by workers
handling DMC or used in their work areas
DMC Cost & Supply
• DMC pricing is just below $ 1.00/lb,
making it price competitive with most
oxygenated solvents except possibly
acetone.
• Drums and bulk isotanks readily available
from multiple factories in China. DMC is
used in very large volumes in China for
coatings primarily because of its low cost.
• Totes can be filled from isotanks.
• Long term a bulk tank in USA is possible
DMC – Toxicity
• DMC (like all methyl esters) rapidly deesterifies in the body to methanol & CO2
• DMC has low acute oral toxicity (LD50 rat
12,900 mg/Kg, LD50 mouse 6,000 mg/Kg)
• DMC was found to be negative in mutagenic
tests (in vitro Ames & comet assay)
• Readily biodegradable and has low potential to
bio-accumulate or be persistent in environment
• Not expected to be toxic to fish or bacteria
(possibly toxic to algae)
DMC & Methanol toxicities
• EPA feels teratogenicity is major endpoint
health concern of environmental exposure for
Methanol (and therefore DMC)
• DMC is not mutagenic or genotoxic
• Well run study by Exxon/Mobil on DMC’s
teratogenic potential confirms it is virtually
identical to Methanol’s (NOEL 1,000 ppm)
• Kowa recommends an 8 hour industrial PEL of
100 ppm based on DMC’s toxicity profile
California OEHHA Assessment
• California's Office of Environmental Health
Hazard Assessment issued a toxicity
assessment of DMC in Dec.2009 that used
the toxicity of its primary metabolite
methanol and existing DMC studies to issue
a toxicological assessment of DMC
• Reported there were no concerns that DMC
like methanol would be carcinogenic
Calif. OEHHA Conclusion
• OEHHA report concluded that doses levels
of DMC likely to be achieved by
environmental exposures to the general
public by inhalation appears to have
“relatively minor” environmental health
concerns
• Established interim acute and chronic REL,
where the acute REL is identical to MEK’s
and the chronic REL similar to Isopropanol’s
DMC Azeotropes & Co-solvents
• There have been a few cryptic references in
literature to DMC forming azeotropes with
numerous solvents without further data
• Azeotropes using DMC could be the “wild
card” in developing coating or cleaning
formulations, substantially changing the
evaporation rate, solubility and perhaps
flammability profiles (to over 100 °F ?)
• Using DMC & PC together might replace
PCBTF, Xylene, butyl acetate, aromatic 100
Propylene Carbonate
• Propylene Carbonate is a very slow
evaporating solvent (evaporation rate <.005,
BuAc =1). This will restrict its solvent use.
• Low viscosity 2.4 cps, high flashpoint 253º F
• Practically non-toxic by oral, dermal or
Inhalation, slight skin irritant, eye irritant
• Available from Kowa from same Chinese
source as our Dimethyl Carbonate.
Propylene Carbonate
• Propylene Carbonate’s very low toxicity
profile allows it’s use in cosmetic products,
therefore PC safe for all consumer items
• Readily biodegradable
• Useful as a co solvent, wetting agent or
tailing solvent (last solvent to evaporate).
• Literature suggest can be used in binary &
tertiary solvent systems to replace common
solvents like trichlorethane and toluene
BENZOTRIFLUORIDE - BTF
• Proposed VOC exempt solvent, EPA
recently tabled petition due to recently
revised MIR values in 2009
• Low MIR of 0.28 (2009) should shortly be
allowed for aerosol coatings on federal
level, now allowed in Aerosol coatings in
Calif. with a MIR value of .26 (2004 table)
• Almost a direct replacement for toluene,
similar solvency and evaporation rate (2.8)