DSHW-1999-002768 - 0901a0688013aea8

THMOKOL PROPULSION GROUP
P O BOX 707
„„,„, ,, ,,,.„,„.,„,„, AEROSPACE i INDUS1RIAL TECHNOIOGIES
BRIGHAM CITY, UT 84302-0707
801-863-3511
MAR ] 0 1999
8 March 1999 ^.O/O^'l
8470-CY99:ST017 ,„ "''"'Sion of Solid & Hazardous Wasfe
Utah Department of Environmental Quality
Mr. Dennis R. Downs, Executive Secretary
State ofUtah
Department of Environmental Quality
Division of Solid and Hazardous Waste
288 N. 1460 W.
P.O. Box 144880
SaltLakeCity, Utah 84114-4880
Dear Mr. Downs
Subject: Activated Carbon Vents in Accumulation Containers
Thiokol has the opportimity to reduce the amount ofhazardous waste generated and shipped
from our facilities by using the "generator treatment in an accumulation tank or container
exemption" as specified in 51 FR 10168, March 24, 1986, and in several EPA policy letters.
Specifically, Thiokol uses several different types of two-part adhesive and polymer products in
many production processes. Some ofthese two-part materials are RCRA hazardous prior to
mixing (typically only for ignitability) but when mixed and cured do not meet the definition ofa
hazardous waste under 40 CFR 261 or contain any underlying hazardous constituents. The
mixing and curing ofthese materials is a polymerization process that is exothermic and, if done
in a closed or sealed container, requires some minor means of venting for the heating and
expanding air as it cures to prevent an over pressure. The quantities ofthese two-part materials
that would be mixed are small and would be in accumulation containers less than 0.1 m^ (26 gal.)
and as such exempt from the subpart CC air emission standards. The acceptability of having a
closed container meeting standards under 40 CFR 265.173 and also allowing some type of
venting for the containers needs to be determined.
Thiokol proposes to use an open top DOT shipping container as the accumulation container for
the curing (treatment) ofthe two part hazardous waste materials. The lid would be equipped
with an activated carbon canister vent to allow for any pressure generation when the container is
closed. (It is note worthy that the subpart CC mles allow the use of pressure relief vents in
accumulation containers without requiring a treatment ofthe gas that is released. Using activated
carbon canisters would thereby exceed these regulations.) This container will be appropriately
labeled and managed as specified in 40 CFR 262.30. Following the cure time, the material will
be checked to assure that all material has properly cured (is treated). This is simple to determine
as the product will harden when cured. The polymerized material will then be removed from the
accumulation container and disposed as a solid waste. As specified in 40 CFR 268.7 (a)(5), a
Waste Analysis Plan, detailing the testing method used to assure that the treatment process has
been completed, will be prepared and kept on file at the facility. The treatment process will be
the same as the standardized procedures used in the mixing process for the use ofthese two-part
adhesives and polymers. Testing has demonstrated that once hardened these materials will no
longer have the ignitability characteristic or any underlying hazardous constituents.
Your office, during inspecfions of our facility, has concurred with another application ofthe
carbon canister vents in the use of our aerosol piercing and consolidation containers.
Any air emissions resulting from these processes are already accounted for under an Air
Approval Order from the Utah DAQ.
A representative material is a two-part product called Gel Coat, which is used to make repairs on
fiberglass components. The material before use consists ofa "resin" primarily composed of
ignitable styrene monomer which is the component that makes the material RCRA hazardous on
disposal. A small amount (l%-2% by weight) of an activator, methyl ethyl ketone peroxide, is
mixed into the resin to initiate the polymerization process. The MEK peroxide becomes part of
the polymerization linkage in the product and does not volatilize. It takes approximately one day
for the material to totally cure, and when cured, is a hard solid that is no longer ignitable nor has
any other hazardous waste characteristics. Unmixed Gel Coat quickly goes out of specification
and is currently sent offsite to a hazardous waste treatment facility.
Thiokol would mix the waste Gel Coat with product MEK peroxide using the standard mixing
ratios and procedures for the material, allowing to cure in an accumulation container, and once
cured, disposing ofthe material as a non-hazardous waste. There is a concem that a totally
sealed container may be dangerous in this situation with the potential heat and pressure
generation during the curing process. In order to minimize this danger, as previously mentioned,
Thiokol would use an activated carbon canister vent on the accumulation containers. While we
believe that this process would generate only very minimal volatile organics or other hazardous
substances, the activated carbon vent would assure that no materials would be released and
would be protective of human health and the environment.
Thiokol believes that this method of mixing two-part materials is an environmentally sound
application ofthe generator accumulation tank or container treatment exemption and will reduce
the amount ofhazardous waste that is shipped offsite for treatment and disposal. We request
your concurrence on the use ofa closed container including a carbon canister vent on these
accumulation containers. If you have any questions, please contact Paul Hancock at 863-3344.
Sincerely
J. D. Thompson
Director, Environmental, Fire, Security and Medical Services