United States
Environmental Protection
Agency
Risk Reduction and
Engineering Laboratory
Cincinnati, OH 45268
Research and Development
EPA/600/S2-91/018 June 1991
EPA Project Summary
Diaper Industry Workshop
Report
Clyde Dial and George Wahl
This report is the product of a 1-day
workshop on the diaper industry that
was sponsored by the U.S. Environ-
mental Protection Agency (EPA). Four
topics were covered during the work-
shop: public health and safety, recy-
cling, composting, and product life
cycle analysis. The primary objective
of the workshop was to identify areas
within the diaper industry that need
further research that will lead to mini-
mizing the negative effect that diapers
have on the environment. This report
can be used by both the private and
the public sector to pursue such re-
search.
This Project Summary was developed
by EPA's Risk Reduction Engineering
Laboratory, Cincinnati, OH, to announce
key findings of the research project
that Is fully documented In a separate
report of the same title (see Project
Report ordering Information at back).
Introduction
In response to the recent heightened
concern about the effect that diapers have
on the environment, and as part of EPA's
continuing effort to transfer technical infor-
mation to the public, EPA held a 1-day
workshop on the diaper industry. More
than 30 representatives from industry, gov-
ernment, consulting firms, and waste han-
dling companies came together to discuss
issues relating to diapers and to identify
areas needing further research. The work-
shop was not a forum for debating whether
disposable or reusable diapers were the
more environmentally sound choice. The
topics discussed during the workshop were
public health and safety, recycling,
composting, and product life cycle analy-
sis.
The research needs defined during the
course of the workshop are detailed in the
report summarized here. Both the private
and the public sector can use the full
report to select research projects that will
lead to improving diapers and lessening
their negative effect on the environment.
Procedure
The focus topics for the workshop were
selected for their relevance to the diaper
industry and to the research that EPA is
currently pursuing. The chosen partici-
pants represented diverse knowledge and
viewpoints about the current state of the
diaper industry: the reusable and the
disposable diaper manufacturers; waste
haulers, recyclers, and composters; con-
sulting firms that have conducted life cycle
analyses of diapers; academia; and vari-
ous EPA offices.
Each of the four sessions, one on each
of the focus issues, began with a brief
presentation on the issue, was followed
by a discussion period, and concluded
with a summary of the research issues
that the participants had identified during
the discussion period.
The overviews and research needs are
summarized, by topic, below. The re-
search needs are limited to the knowl-
edge of the participants at the workshop
and are not meant to be comprehensive.
In addition, some of the issues discussed
in this report may have already been re-
searched, but the workshop participants
were unaware of the research.
Printed on Recycled Paper
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Public Health and Safety
Overview
To open this session, Wayne Turnberg
of the Washington State Department of
Ecology gave a presentation on the Wash-
ington State Infectious Waste Project. This
study, which assessed the risk of human
infectious disease acquired during the
course of disposal, concluded that human
pathogens are routinely introduced into
the solid waste stream from residential
sources including disposable diapers and
from medical waste stream sources. Once
in a properly operated landfill, pathogens
are not likely to migrate and may become
inactive. No evidence of human infec-
tious disease from infectious agents
present in municipal solid waste landfills
or the waste stream was identified based
on the literature search conducted for the
report.
Research Needs
Human exposure considerations as they
relate to the diaper industry must be fur-
ther examined for a better understanding
of the human exposure aspects of han-
dling and processing soiled diapers to pro-
vide ways to control such exposure. Be-
low are examples of creditable informa-
tion that should be obtained and distrib-
uted.
• A study is needed of the occupa-
tional infection risk to waste workers
and the source of that risk. Sero-
logic markers for hepatitis B and
other appropriate pathogens should
be employed. This study should
identify risks associated with collec-
tion, handling, and processing of
these waste materials.
• A study is needed of the captured
aerosols found in the void spaces of
closed receptacles (i.e., plastic trash
bags) containing soiled diapers and
the effect of these aerosols on hu-
mans during handling and collection
of these containers by reusable dia-
per services. Human exposure to
these aerosols during the launder-
ing of reusable diapers should be
evaluated. Exposure assessments
during collection of disposable dia-
pers and their handling during recy-
cling or composting are needed.
• An epidemiological study is needed
to determine any health risk associ-
ated with recycling or with
composting practices of this solid
waste.
Additional public health and safety re-
search not related directly to human ex-
posure should:
examine the survivability of patho-
gens in the reusable diaper wash
process;
evaluate different biocides used for
sanitizing reusable diapers;
define, quantitatively, the sources of
microorganisms that enter the waste
stream, including human and animal
wastes;
determine the need for biological
testing of landfills to monitor human
pathogens; and
study the macro effects of combin-
ing sewage sludge with the munici-
pal solid wastestream.
Recycling
Overview
The first presentation, given by Nancy
Eddy of Procter and Gamble, focused on
the Seattle Diaper Reclamation Project.
This is a cooperative effort among Procter
and Gamble (manufacturer of disposable
diapers), the Seattle Solid Waste Utility, a
local diaper service, and Rabanco (a solid
waste recycling firm). The goal is to de-
termine the technical and economic feasi-
bility of recycling disposable diapers.
During the course of the project, the
potential market for reclaimed pulp, plas-
tic, and absorbent gel materials will be
determined, and the Seattle Solid Waste
Utility will complete an economic evalua-
tion, which will be verified by an indepen-
dent consulting firm. If recycling is deemed
economically feasible, the project will be
turned over to Rabanco for continuous
processing of disposable diapers. This
project began in June 1990.
The second presentation, given by Gerry
Sheehan of Weyerhaeuser, focused on
Weyerhaeuser's San Diego Recycling
Project. The goal of the project was to
design a recycling process that was eco-
nomically feasible, was insensitive to mar-
ket fluctuations, required minimal capital,
and required no major changes in current
consumer habits. The drawbacks revealed
by the project included contamination of
the recovered pulp with absorbent gel
material, high water usage, and costly de-
livery and pickup of diapers. Future re-
search efforts include proving that the re-
claimed pulp's purity is not impaired be-
cause of gel contamination, testing the
pulp for composting, exploring low-cost
methods for extracting gel, and investigat-
ing ways to include disposable diapers
from the retail trade in the collection pro-
gram.
Research Needs
Research related to improving the qual-
ity of recycled diaper material should:
• determine the impact of contamina-
tion by gelling material on pulp qual-
ity;
• explore low-cost methods for extract-
ing gelling material;
• find methods to efficiently separate
different types of plastics;
• develop catalysts that enhance the
properties of co-mingled plastics;
• study the feasibility of reducing the
diversity of plastic for diaper liners,
bags, adhesive strips, and elastics;
• evaluate the effect of different col-
lection and separation methods on
the cost of recycling and consumer
acceptance;
• conduct material balances to deter-
mine how much reclaimed pulp and
paper are actually returned to the
market and not discarded as pro-
cess waste;
• determine the energy requirement for
reclamation; and
• include collaborative efforts among
the EPA, the Department of Com-
merce, the Food and Drug Adminis-
tration, and the General Services
Administration to examine which gov-
ernment actions can selectively "pro-
mote" use of reclaimed materials.
Composting
Overview
The first presentation, given by Nancy
Healy of Recomp, focused on the St.
Cbud, Minnesota, Diaper Compost Project.
The goal of this project was to demon-
strate the viability of composting dispos-
able diapers. For this project, the per-
centage of diapers entering St. Cloud's
aerobic composting process was increased
from approximately 2% to 7.6% of the
municipal solid waste feed to magnify the
effects of disposable diapers on the
composting process. Preliminary results
indicate that the compost produced in this
study did not differ from the normal com-
post produced at the St. Cloud facility.
The plastic backsheets from the diapers
are not compostable and were removed
during the composting process by screens
that eliminate materials over 1.5 in. in
diameter.
For the second presentation, Steven
Howard of Amerecycle provided an over-
view of the Sumpter County, Florida, Com-
post Facility. Before being composted, the
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municipal solid waste goes through sev-
eral processes at this facility including seg-
regation of household hazardous waste,
shredding, magnetic separation, metal de-
tection, hand-sorting, and moisture addi-
tion. The waste is then placed in open-air
windrows. Aeration and inoculation with
microorganisms are used to promote
composting. This facility has not con-
ducted any specific studies on composting
diapers but has had no problems from the
diapers that are processed at the facility.
Research Needs
Further research in composting should:
• conduct a systems study comparing
composting with landfilling,
• compare sewage sludge composting
with municipal solid waste
composting,
• perform pilot studies on the separa-
tion of diaper materials,
• examine how trace impurities (like
gel material) affect the quality of com-
post material, and
• determine the economic viability of
composting.
Other research not directly related to
composting should:
• compare aerobic and anaerobic deg-
radation in a controlled landfill with
an outlet provided to collect meth-
ane, and
• conduct feasibility studies on the de-
velopment and use of a flushable
diaper.
Product Life Cycle Analysis
Overview
Jere Sellers of Franklin Associates pro-
vided an overview of product life cycle
analysis (PLA). PLAs must examine multi-
media factors including energy use, natu-
ral resource use, the quality of air, water,
and land when determining the environ-
mental impacts of a product. Comparison
of products within a PLA must be fair and
unbiased. Franklin Associates is currently
doing a life cycle analysis on various dia-
per products for the American Paper Insti-
tute.
Anthony Montrone of Arthur D. Little
gave a presentation on his firm's PLA of
diapers. The study examined the health,
environmental, and economic effects of
both reusable and disposable diapers. The
study showed that both types of diapers
negatively affect the environment. Dis-
posable diaper manufacture and use gen-
erate more municipal solid waste than do
reusable diapers. Reusable diapers use
more energy and water and result in higher
levels of total air and water pollution.
Research Needs
Research needs related to life cycle
analysis centered on the need to provide
guidance on approaches to conducting
these analyses and their use. Further life
cycle studies should:
• identify the variables that significantly
affect the final results for all diaper-
related life cycle analyses,
• determine where diaper-related life
cycle analysis should begin and end,
and
• use life cycle analysis to find target
areas that should be changed to re-
duce the environmental effects of
both single-use and reusable dia-
pers.
Summary Statement
The diaper industry workshop focused
on four important issues: public health and
safety, recycling, composting, and prod-
uct life cycle analysis techniques. A ma-
jority of participants believed that the health
and safety issues related to diapers cur-
rently receive more public scrutiny than is
warranted. They concluded that there is
probably no significant public health and
safety problems related specifically to dia-
per handling, recycling, or disposal in prop-
erly operated and constructed landfills.
Because diaper disposal is a highly vis-
ible public issue, however, more definitive
health and safety studies should be con-
ducted on the handling and processing of
diapers. This would clearly enable public
health officials to define any health and
safety issues related to diaper handling
and to dispel unwarranted fears about
health problems associated with diapers.
The issues related to recycling and
composting of diaper materials focused
on how to make these technologies eco-
nomically viable. The consensus of the
participants was that the major issues re-
lated to recycling, beyond making it eco-
nomically feasible, were the quality of the
product and the acceptance of recycled
materials in the marketplace.
The conclusion from the PLA discus-
sion was that these techniques are an
excellent way to identify aspects of a
product's life cycle that can be targeted
for further study. Such studies would fo-
cus on ways to increase the length of
product life, the reuse of product materi-
als, or ways of producing the product that
result in less waste.
Many research needs were identified
during the course of this workshop. Fur-
ther investigation into these research is-
sues by both the private sector and the
public sector will lead to opportunities to
lessen the adverse environmental impacts
of diapers and to improve the health and
safety of those who come into contact
with diapers. Initiation of research projects
in this area by EPA is contingent on the
Agency's priorities.
The full report was submitted in fulfill-
ment of Contract No. 68-C8-0061 by Sci-
ence Applications International Corpora-
tion (SAIC) under the sponsorship of the
U.S. Environmental Protection Agency.
.S. GOVERNMENT PRINTING OFFICE: IWI - S48-OM/40015
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Clyde Dial and George Wahl are with Science Applications International Corp.,
Cincinnati, OH 45203.
Mary Ann Curan is the EPA Project Officer (see below).
The complete report, entitled "Diaper Industry Workshop Report," (Order No.
PB91-191262/AS; Cost: $15.00, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Risk Reduction and Engineering Laboratory
U.S. Environmental Protection Agency
Cincinnati, OH 45268
United States
Environmental Protection
Agency
Center for Environmental
Research Information
Cincinnati, OH 45268
BULK RATE
POSTAGE & FEES PAID
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PERMIT No. G-35
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Penalty for Private Use $300
EPA/600/S2-91/018
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