August 28, 2003

Ms. Kelly A. Rimer

Risk and Exposure Assessment Group

Emission Standards Division (C404-01)

U.S. Environmental Protection Agency

Research Triangle Park, NC 27711

Electronic Docket No. OAR-2003-0028

Docket ID No. A-99-03

> **Re: [List of Hazardous Air Pollutants, Petition Process, Lesser
> Quantity Designations, Source Category List, Proposed Rule in 68 F.R.
> 32605 (May 30, 2003) -- Comment In Support of Removal of MEK as a
> Listed Hazardous Air Pollutant]{.underline}**

Dear Ms. Rimer:

Jefferson Smurfit Corporation (U.S.) and Stone Container Corporation,
both doing business as Smurfit-Stone Container Corporation
("Smurfit-Stone"), are submitting this comment in support of EPA's
proposed removal of Methyl Ethyl Ketone ("MEK") (2-butanone, CAS No.
78-93-3) from the Clean Air Act's list of hazardous air pollutants
("HAPs"), as proposed at 68 F.R. 32605 (May 30, 2003). Smurfit-Stone is
a member of the Flexible Packaging Association ("FPA") and the American
Forest & Paper Association ("AF&PA") and also endorses the comments of
FPA and AF&PA supporting U.S. EPA's proposal.

Smurfit-Stone has facilities across the United States engaged in
multiple printing and coating operations and processes that must meet
ever-changing technical product demands and regulatory requirements for
the packaging of foods, pharmaceuticals, household goods, garden
supplies, cosmetics and other industrial, institutional and agricultural
applications. MEK is used as a solvent in some of our printing and
coating operations. Some facilities operated by Smurfit-Stone and by
others are subject to the HAP or "MACT" regulation for the printing
sector (40 CFR Part 63, Subpart KK) solely due to their use of MEK. As
discussed in the FPA comments supporting the proposed delisting, despite
MEK's potential cost and environmental benefits for many applications,
our facilities have greatly reduced their use of MEK, at least in part
because it was a listed HAP. However, facilities not now subject to MACT
requirements still face the possibility that a change in customer
requirements or other factors might best be met by use of MEK in an
amount that would trigger regulation under the MACT rules for the
printing sector or the paper and other web coating sector (40 CFR Part
63, Subpart JJJJ).

Smurfit-Stone does not anticipate that its overall use or emissions of
MEK will increase significantly if MEK is delisted. However, delisting
MEK will provide our facilities more flexibility to use MEK when it is
commercially necessary and is not prevented by other non-HAP regulatory
requirements. If MEK is delisted, U.S. EPA should address the effect of
the delisting on MACT applicability to a source that was deemed "major"
solely due to its potential to emit MEK. As discussed below, based on
extensive research and technical data, MEK should not be listed as a
HAP. MEK should instead be regulated the same as other non-HAP
compounds. Hence, if MEK is delisted, we request that U.S. EPA expressly
recognize this as an exception to its "once in, always in" policy so
that facilities that are subject to MACT only because of their past and
current use of MEK will no longer be subject to MACT after MEK is
delisted. The recognition of this exception should be published as part
of the final actions on both the proposed MEK delisting and the proposed
changes to 40 CFR Part 63 General Provisions (68 F.R. 26,249 (May 15,
2003)).

As summarized in the preamble to the proposed delisting, U.S. EPA has
based its proposal to delist MEK on a lengthy, careful, and thorough
assessment of the potential environmental and health impacts of MEK use
and emissions within the United States. Even using conservative
assumptions about the possible ambient concentrations of pollutants from
MEK use and their possible health and environmental impacts, U.S. EPA's
assessment and the studies in the docket clearly show that there is no
reasonable likelihood of adverse impacts that would justify continued
listing of MEK as a HAP. Even using conservative assumptions, MEK will
have no reasonably anticipated adverse human health or ecological
impacts at expected worst case ambient concentrations. (68 F.R. at pp.
32,615-32,616.) MEK is neither persistent in the environment
(atmospheric half-life of nine days) nor bioaccumulative, and readily
biodegrades in both aerobic and nonaerobic conditions. MEK is not
classified as a carcinogen. Moreover, as U.S. EPA explains in the
preamble, available genotoxicity tests for MEK are essentially negative,
and the structure of MEK does not indicate a carcinogenic hazard. (68
F.R. at p. 32,615.) As it disperses and decomposes, some of the MEK can
be transformed into acetaldehyde and formaldehyde, both of which are
classified as probable human carcinogens. However, as is demonstrated in
the docket and explained in the preamble, even using conservative
assumptions, transformation of MEK emissions into acetaldehyde and
formaldehyde may not reasonably be anticipated to cause adverse effect
to human health. (68 F.R. at pp. 32,616-32,617.)

Inhalation of MEK is the exposure pathway of primary concern. The
complete delisting petition included an extensive air quality modeling
study of facilities emitting MEK, which was supplemented by U.S. EPA's
own analysis. Without repeating the details that are well-summarized in
the preamble to the delisting proposal, even using relatively
conservative assumptions and modeling, the highest modeled maximum
annual ambient concentration (using a Tier 3 model) was 1.2 mg/m3, and
this was located at the entrance to an adjacent industrial facility
where there were no human or environmental receptors. (68 F.R. at p.
32,611.) Otherwise, conservatively estimated maximum annual
concentrations were all less than 1 mg/m3 and estimated maximum 24-hour
and 1-hour averages were not expected to exceed 10 mg/m3 and 25 mg/m3,
respectively. U.S. EPA correctly found that human exposures to MEK "may
not reasonably be anticipated" to exceed concentrations of 1 mg/m3
annual average, 10 mg/m3 24-hour average, or 25 mg/m3 maximum 1-hour
average. (68 F.R. at p. 32,613.)

U.S. EPA's reference concentration ("RfC") for inhalation exposure to
MEK (1.0 mg/m3) was established in 1992, prior to U.S. EPA's current
guidelines for calculating RfCs. The RfC represents a level that a human
population (including sensitive subgroups) could be exposed to for a
70-year lifetime without appreciable risk of noncancer adverse health
affects. U.S. EPA has initiated a review of the MEK RfC, which is not
yet complete (see 67 F.R. at p. 1212 (Jan. 9, 2002)). However, the
preliminary results indicate that an RfC of 9 mg/m3 should be adequate
to protect against non-cancer health effects. (68 F.R. at p. 32,615.) In
the preamble to the proposed rule (68 F.R. at p. 32,615), U.S. EPA asked
for comment on its prospective RfC of 9 mg/m3 and its health risk
characterization based on the prospective RfC. Smurfit-Stone believes
that based on the data in the docket, and for the reasons aptly
summarized and explained in the preamble, an RfC of at least 9 mg/m3 is
supported by the record and amply justified; hence, U.S. EPA's use of
the prospective RfC to evaluate MEK and its characterization of the
noncancer human health risks from MEK (or the absence thereof) are fully
supportable. Indeed, U.S. EPA's comparison of the maximum annual average
ambient concentration predicted for any facility, using conservative
modeling and assumptions, with a conservative RfC, which is intended to
protect human health for a 70-year lifetime exposure, is extremely
conservative.

U.S. EPA also requested comments on whether it would be appropriate to
delist MEK "if the final RfC is different from the prospective RfC." (68
F.R. at p. 32,615.) The modeling study that is part of the docket and
described in the preamble to the proposal demonstrates that the maximum
annual average ambient concentration from MEK emissions is less than 1
mg/m3, and, as U.S. EPA has determined, the actual exposures, even of
people living in the immediate vicinity of MEK emission sources, would
typically be at least a factor of two to ten less than 1 mg/m3. (68 F.R.
at p. 32,616.) Hence, the information and analysis in the docket and in
the preamble support delisting MEK as long as the final RfC is no lower
than the 1 mg/m3 standard that is now under review. Smurfit-Stone
therefore requests that U.S. EPA finalize the delisting as long as the
final RfC for MEK is not reduced below the 1992 RfC of 1 mg/m3.

In its delisting proposal, U.S. EPA stated that it expected to take
final action on its review of the 1992 MEK RfC in about September of
this year and would thereafter take final action on the proposed
delisting. Smurfit-Stone believes that the information in the docket
supports a final MEK RfC no lower than prospective RfC of 9 mg/m3.
However, as indicated above, Smurfit-Stone believes that the information
in the docket supports delisting MEK even if the RfC for MEK is not
increased. Hence, unless new information is submitted that causes U.S.
EPA to believe that the final RfC will be less than 1 mg/m3, U.S. EPA
should finalize the MEK delisting even if final action on the MEK RfC is
delayed.

Smurfit-Stone strongly supports U.S. EPA's delisting of MEK from the HAP
list. The docket amply supports that MEK is not a HAP. Moreover,
delisting MEK will allow some facilities greater flexibility to use MEK
without triggering MACT requirements. As explained in FPA's comments, in
some applications, MEK provides better performance, with lower VOC
emissions and a lower cost without adversely affecting the health and
welfare of our workers and neighbors or the environment. As part of its
delisting, we ask U.S. EPA to expressly recognize that facilities
subject to MACT only because of their past and current use of MEK will
no longer be subject to MACT.

If you have questions or require further information, please call me at
314-746-1154.

> Sincerely,
>
> Roy C. Cobb, Jr.
>
> Senior Environmental Counsel
>
> Smurfit-Stone Container Corporation
>
> 8182 Maryland Avenue
>
> Clayton, Missouri 63105
>
> Tel. 314-746-1154
>
> FAX 314-746-1333
>
> e-mail rcobb@smurfit.com