MANUFACTURER REQUEST FOR RISK EVALUATION
DIISODECYL PHTHALATE (DIDP)
Table of Contents
Background 2
Contact information of entity submitting the request 2
Substance identity 2
Conditions of use requested for evaluation 3
Information relevant to the risk evaluation of DIDP 4
Information relevant to the human health hazard potential of DIDP - 5
US CPSC- 6
European Union - 6
Australia NICNAS- 7
Environmental Canada and Health Canada- 7
Information relevant to the exposure potential of DIDP - 9
Information relevant to the persistence and bioaccumulation of DIDP - 11
Potentially exposed or susceptible subpopulations relevant to the EPA risk evaluation - 11
Potential for storage of chemical substance near significant sources of drinking water, including
storage facility location and nearby drinking water source(s) - 12
DIDP production volume - 13
Addendum 13
Appendix A -- Substance Identity Information
Name and substance identifiers 15
Structure 15
Considerations for Evaluating both CAS Numbers as a Single Substance 17
Appendix B -- Production and Use
Production volume 18
Uses 18
Existing regulations restricting use 19
Intended uses requested for evaluation 19
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May 23, 2019
Office of Pollution Prevention and Toxics (OPPT)
Environmental Protection Agency
1200 Pennsylvania Ave., NW
Washington, DC 20460-0001
Background
The American Chemistry Council's High Phthalates Panel (ACC HPP) represents major producers,
importers, and users of DINP, DIDP, and other high molecular weight phthalates. Pursuant to Section
6(b)(4)(C)(ii) of the Toxic Substances Control Act (TSCA) and 40 C.F.R. Section 702.37, ExxonMobil
Chemical Company ("the manufacturer"), through the ACC High Phthalates Panel, formally requests
that the Agency conduct a risk evaluation of diisodecyl phthalate (DIDP), represented by the two
Chemical Abstracts Service Registry Numbers (CASRNs) 26761-40-0 and 68515-49-1. This document
and Appendices A-C provide the information to be submitted as set forth in §702.37(b).1
Contact information of entity submitting the request
The High Phthalates Panel is comprised of companies that manufacture, compound, convert, or import
certain high molecular weight phthalates.2
Substance identity
The chemical identity of DIDP is provided in Appendix A. Tables 1-3 of Appendix A include all
reasonably known names of the chemical substance, including common or trade names and CAS
numbers. Structures of representative isomers of the chemical substance are also provided in figures
1-3 of Appendix A. As noted previously, this substance is represented by two CAS numbers. The
structures of DIDP illustrated in figures 1 and 2 of Appendix A represent CAS number 26761-40-0.
DIDP identified by CAS number 68515-49-1 refers to a multi-constituent substance comprised of C9-
C11 (Cio-rich) branched dialkyl phthalate esters, illustrated in figure 3 of Appendix A. Both CAS numbers
contain mainly C10 dialkyl phthalate esters, having identical molecular formula C28H46O4 (with a
molecular weight of approximately 446.7 Da).3 As noted in Appendix B of this submission, unlike CAS
number 68515-49-1, CAS number 26761-40-0 is not currently registered under the European Union
(EU) REACH chemical management system. However, U.S. production volumes have been reported
for both CAS numbers to EPA's Chemical Data Reporting database, albeit CAS number 26761 -40-0 is
reported at considerably lower production volumes than CAS number 68515-49-1.
As described in Appendix A, reviewing agencies, including the European Chemicals Bureau/Chemicals
Agency (ECHA), Australia NICNAS, Environment Canada and Health Canada, and the US CPSC have
considered the two CAS numbers to be toxicologically equivalent and have evaluated them as a single
substance. Hence, this request is to evaluate the risk of both CAS numbers as a single substance.
1 Unless otherwise indicated, all section citations are to 40 C.F.R.
2 See https]//phthalates.americanchemistrv.com/About-Us/
3 See Consumer Product Safety Commission. 2010. Toxicity review of Di(isodecyl) Phthalate (Apr. 7, 2010), p. 2.
https://www.cpsc.gov/s3fs-public/toxicitvDlDP.pdf. The requesting manufacturers agree with this description.
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Conditions of use requested for evaluation
The Agency defines conditions of use as "circumstances, as determined by the Administrator, under
which a chemical substance is intended, known, or reasonably foreseen to be manufactured,
processed, distributed in commerce, used or disposed of." §702.33. The uses of DIDP are summarized
in Appendix B. The primary intended, known or reasonably foreseen use of DIDP is as a plasticizer to
impart flexibility to polyvinyl chloride (PVC) in consumer and industrial applications.4 5 6 7 These
applications include building and construction (electrical wire coating, vinyl tiles, resilient flooring, PVC-
backed carpeting, roofing, wall coverings etc.), automotive (upholstery and interior finishes such as
synthetic leather or PVC skins for car interior seats and dashboards, undercoating, insulation for wire
and cable, window glazing etc.), flexible tubes, profiles, and hoses. Other DIDP applications include
use in inks, adhesives, sealants, synthetic lubricants and engine oils. This list of uses is consistent with
those identified for DIDP in existing European Union (EU) REACH registrations (see Appendix C of this
request for links to EU REACH registration dossiers for DIDP).
These uses mirror those reported for DIDP in the US. 2016 CDR data reported for CASRN 26761-40-
0 indicates that it is used for industrial and commercial applications such as incorporation into
formulation, mixture, or reaction product for making adhesives and sealant chemicals, petroleum
lubricating oil and grease manufacturing, as a plasticizer and for use in manufacturing adhesives and
sealants. With respect to CASRN 68515-49-1, the 2016 CDR data reports use for industrial, consumer
and commercial applications such as incorporation into an article or into formulation, mixture, or
reaction product for manufacturing adhesives and sealants, paints and coatings, plastic products, and
resins (as a plasticizer).
The manufacturer, through the ACC HPP, requests that the following uses be evaluated under the risk
evaluation of DIDP:
o DIDP Manufacturing
o DIDP use as a general purpose plasticizer for PVC used in the following applications;
o Building and construction - electrical wire coating, vinyl tiles, resilient flooring, PVC-
backed carpeting, wall coverings, roofing, etc.
o Automotive - upholstery and interior finishes (e.g. synthetic leather for car seats, interior
PVC skins for dashboards and shift boot covers), window glazing, body-side molding,
automotive undercoating, molded interior applications, insulation for wire and cable and
wire harnesses.
o Other consumer applications - flexible tubes, hoses, profiles, etc.
o Non-PVC applications - inks, adhesives, sealants and paints, synthetic lubricants and
engine oils.
o Use in PVC for children's toys and childcare articles - From 2009-2017, the US CPSC placed
an interim restriction on the use of DIDP in any children's toys that can be placed in a child's
4 American Chemistry Council (ACC) (2018). Phthalates: High phthalates uses and applications.
https://phthalates.americanchemistrv.com/Hiqh-Uses-and-Applications.html
® IHS Markit. (2018). Chemical Economics Handbook: Plasticizers, pp. 42. 4 May 2018.
6 European Plasticisers (2018). Plasticisers Information Center: Orthophthalates.
https://www.plasticisers.org/plasticisers/orthophthalates/
7 European Chemicals Agency (ECHA) (2010). Review of New Available Information for di-isodecyl phthalate (DIDP). p. 4.
https://echa.europa.eu/documents/10162/13641/didp echa review report 2010 6 en.pdf
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mouth or childcare article at levels greater than 0.1%.8 In 2017, the US CPSC lifted the interim
prohibition, on the basis that continuing the prohibition "is not necessary to ensure a reasonable
certainty of no harm to children, pregnant women, or other susceptible individuals with an
adequate margin of safety" 9 Thus, DIDP may be used in children's toys and childcare articles
without restriction in the United States, unless there are restrictions within a specific state. One
such state restriction is in California, which prohibits DIDP in concentrations greater than 0.1%
in a toy or child care article intended for use by a child under three years of age if that product
can be placed in the child's mouth.10 The manufacturer, through the ACC HPP, requests that
potential DIDP exposure of children from toys and childcare articles be evaluated, consistent
with the Agency's stated concerns in the US EPA 2012 Phthalate Action Plan.11
Information relevant to the risk evaluation of DIDP
TSCA requires EPA to conduct risk evaluations to determine whether there is unreasonable risk to
humans or the environment using the best available science and weight of the scientific evidence.12
The definition of weight of the scientific evidence adopted by EPA states:
"Weight of the scientific evidence means a systematic review method, applied in a manner
suited to the nature of the evidence or decision, that uses a pre-established protocol to
comprehensively, objectively, transparently, and consistently identify and evaluate each
stream of evidence, including strengths, limitations, and relevance of each study and to
integrate evidence as necessary and appropriate based upon strengths, limitations, and
relevance."13
These scientific standards apply to manufacturer requests for risk evaluation and any request must
include all the existing information relevant to the risk evaluation.14 Specifically,
"The request must also include a list of all the existing information that is relevant to whether
the chemical substance, under the circumstances identified by the manufacturer(s), presents
an unreasonable risk of injury to health or the environment. The list must be accompanied by
an explanation as to why such information is adequate to permit EPA to complete a risk
evaluation addressing the circumstances identified by the manufacturer(s), The request need
not include copies of the information; citations are sufficient, if the information is publically [sic]
available. The request must include or reference all available information on the health and
8 Consumer Product Safety Act of 2008 § 108(b)(1), codified at 15 U.S.C. § 20S7c(b)(1). https://www.cpsc.gov/s3fc-
public/pdfs/blk pelf cpsia.pdf. "Children's toy" was defined as a consumer product designed or intended by the
manufacturer for a child 12 years of age or younger for use by the child when the child plays" and "child care article" is
defined as "a consumer product designed or intended by the manufacturer to facilitate sleep or the feeding of children age
3 and younger, or to help such children with sucking or teething." 15 U.S.C. § 2057c(g)(1) [as codified after amendment of
CPSIA],
9 US Consumer Product Safety Commission (CPSC). Prohibition of Children's Toys and Child Care Articles Containing
Specified Phthalates. 82 Fed. Reg. 49938, 49968 (Oct. 27, 2017), https://www.apo.aov/fdsvs/pkg/FR-2017-10-
27/pdf/2017-23267.pdf [hereafter "CPSC Phthalate Rule"].
10 California Health and Safety Code § 108937(b).
11 US EPA. Phthalates Action Plan (Mar. 14. 2012 revision), pp. 8 & 12. https://www.epa.gov/sites/production/files/2015-
09/documents/phthalates actionplan revised 2012-03-14.pdf [hereafter "2012 Action Plan'1.
12 15 U.S.C. 2625(h) and (i); defined at 40 C.F.R. Part 702.33
13 40 CFR Part 702.33
14 40 CFR Part 702
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environmental hazard(s) of the chemical substance, human and environmental exposure(s),
and exposed population(s), as relevant to the circumstances identified in the request."15
To provide EPA with "all existing information that is relevant" to conduct the manufacturer requested
risk evaluation, an extensive literature search was conducted. Appendix C details the protocol used to
comprehensively, objectively, transparently, and consistently identify relevant information in several
databases. The process used comports with the requirements specified by EPA for a weight of the
scientific evidence review method and meets the requirements for submission of a manufacturer
requested risk evaluation under 40 CFR Part 702.37.
Specifically, Appendix C contains bibliographic citations to publicly available information that is relevant
to whether DIDP, under the circumstances identified above, presents an unreasonable risk of injury to
health or the environment. We note that DIDP (and phthalates in general) has been the subject of
considerable academic and regulatory interest for several decades. Thus, while the list in Appendix C
is robust, it does not necessarily represent all existing hazard and exposure information on DIDP.
Nevertheless, it does include all the existing information that is relevant to whether DIDP, under the
conditions of use noted herein, presents an unreasonable risk of injury to health or the environment,
including the following: information on the hazard and exposure potential of DIDP, information on the
persistence and bioaccumulation of DIDP, information on potentially exposed or susceptible
subpopulations relevant to the EPA risk evaluation, information on the potential for storage near
significant sources of drinking water, and information on DIDP production volumes. The manufacturer,
through the ACC HPP, believes that having provided all the existing information listed above, such
information is more than adequate for EPA to conduct a thorough risk evaluation addressing the
conditions of use we have identified. The following provides an overview of the information referenced
in Appendix C.
Information relevant to the human health hazard potential of DIDP -
In its 2012 Phthalates Action Plan 2014 update to the TSCA Work Plan, the Agency indicated that the
critical endpoint of concern for DIDP is developmental toxicity (hazard score of 3 - "high" assigned).16
In addition, in the Action Plan, the Agency indicated that it intended to consider results of risk
evaluations being conducted by the US Consumer Product Safety Commission (CPSC), the FDA, and
the Agency's IRIS program to inform the extent of any future TSCA Section 6 action addressing the
listed phthalates, including DIDP.17
Thus, the most relevant information with respect to the reproductive/developmental hazard and risk
assessment of DIDP is the recently completed regulatory risk evaluation from the US CPSC's Chronic
Hazard Advisory Panel (CHAP) (2014), along with other similar completed risk evaluations from the
European Union (2003 and 2013), the Australian National Industrial Chemicals Notification and
Assessment Scheme (NICNAS) (2015) and Environment Canada and Health Canada (2015).
References to these risk evaluations are available on page 2 of Appendix C.
15 Environmental Protection Agency; Procedures for Chemical Risk Evaluation Under the Amended Toxic Substances
Control Act, 82 Fed. Reg. 33,749 (July 20, 2017)(codified at 40 C.F.R. Pt. 702.37).
16 2012 Action Plan, note 11, pp. 1 & 4; TSCA Work Plan for Chemical Assessments: 2014 Update, p. 12.
https]//www.epa.qov/assessinq-and-manaqinq-chemicals-under-tsca/tsca-work-plan-chemical-assessments-2014-update
[hereafter "2014 Work Plan'l.
17 2012 Action Plan, note 11, pp. 10-11 ("Next Steps").
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US CPSC-
The CPSC's CHAP conducted an evaluation of the toxicity information available on DIDP, with a focus
on reproductive and developmental toxicity.18 The CHAP concluded that DIDP "does not appear to
possess antiandrogenic potential."™ For all other potential systemic effects, the CHAP concluded that
the margin of exposure (MOE) for DIDP in humans "is considered likely to be relatively high."20 Overall,
the CHAP indicated that it did not find "compelling data to justify maintaining the current interim ban on
the use of DIDP in children's toys and child care articles" and thus recommended a lifting of the interim
ban.21 In 2017, the US CPSC adopted the recommendation of the CHAP, concluding that DIDP "does
not lead to male developmental reproductive toxicity in animals and, therefore, does not contribute to
the cumulative risk" and that "continuing the prohibition ... is not necessary to ensure a reasonable
certainty of no harm to children, pregnant women, or other susceptible individuals with an adequate
margin of safety."22 Thus, DIDP use is now allowed in children's toys, including those that may be
placed in a child's mouth, and childcare articles, unless there is a restriction within a specific state.23
The manufacturer, through the ACC HPP, considers exposure to DIDP in toys and childcare articles to
be worst-case, especially in children and pregnant women, who would be considered the most
susceptible individuals with respect to DIDP exposure, consistent with the Agency's stated concerns in
the 2012 Phthalate Action Plan.24 The US CPSC's conclusions thus provide adequate confidence that
DIDP poses no unreasonable developmental toxicity risk to humans, including the most susceptible
populations.
European Union -
The European Union (EU) has published two detailed risk evaluations of DIDP, in 2003 and 2013.25'26
Both risk evaluations concluded that there was no need for further testing or risk mitigation with respect
to exposure to DIDP for workers and consumers.27 The 2013 report evaluated the risk of exposure to
DIDP from several uses including toys and childcare articles (e.g. school supplies), skinny vinyl leather
pants (assuming these are worn 10 hours/day for 2 weeks per month by pregnant women), indoor air,
house dust and food in children and adults.28 The EU report found no reproductive or developmental
toxicity risk with DIDP exposure in any of the uses evaluated, consistent with the US CPSC's
conclusions.29
18 Chronic Hazard Advisory Panel (CHAP) on Phthalates. 2014. Chronic Hazard Advisory Panel on Phthalates and
Phthalate Alternatives Final Report (2014), pp. 100-105, A-26&28, B-13-14. https://www.cpsc.gov/s3fs-public/CHAP~
REPORT-With-Appendices.pdf [hereafter "CHAP 2014"].
19 CHAP 2014, note 18, p. 104.
20 Id. See also id. Section 5.3.3.4.3, page 104 ("Risk"): "Based on the lowest [point of departure] (15 mg/kg-day), the
[margins of exposure] range from 2500 to 10,000 for median intakes and from 586 to 3300 for 95th percentile intakes."
21 Id. pp 104-105.
22 CPSC Phthalate Rule, note 9, p. 49968
23 See note 10 and associated text regarding restrictions in California.
24 2012 Action Plan, note 11, pp. 8 & 12.
25 European Chemicals Bureau. 2003. European Union Risk Assessment Report on 1,2- benzenedicarboxylic acid, di-C9-
11-branched alkyl esters, C10-rich and di-"isodecyl" phthalate (DIDP). https://echa.europa.eu/documents/10162/190cf4c4-
b59?-4534-9b? 1 ~f?9fce55050b [hereafter "ECB 2003"!.
26 European Chemicals Agency (ECHA). 2013. Evaluation of new scientific evidence concerning DINP and DIDP in
relation to entry 52 of AnnexXVII to REACH Regulation (EC) No 1907/2006. August 2013.
https://echa.europa.eu/documents/10162 37e-de40-4044-93e8-9c9ff1960715. [hereafter "ECHA 2013"].
27 ECB 2003, note 25, pp. VII-VIII; ECHA 2013, note 26, pp. 7-8.
28 ECHA 2013, note 26, pp. 267-276.
29 Id., Tables 4.91, 4.94, 4.102, 4.108, 4.113, and 4.117.
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Australia NICNAS -
In 2015, the Australian NICNAS published a detailed hazard and risk assessment of DIDP exposure
through the use of plastic toys and childcare articles.30 For their assessment, NICNAS identified two
critical health effects observed in rodents: repeated-dose toxicity (increased liver weights) and
developmental effects (increased skeletal variations at non-maternotoxic dose)31 To estimate daily
internal oral dose for a child who may be exposed to DIDP in toys or childcare articles, NICNAS
assumed a six-month old infant, having the lowest body weight among the group (7.5 kg based on the
50th percentile value for males and females combined), would exhibit the maximum mouthing behavior
with a typical and reasonable worst-case mouthing time of 0.8 hours/day and 2.2 hours/day,
respectively.32 Assuming the use of toys and childcare articles containing DIDP by children, NICNAS
derived margins of exposure (MOE) of 1980 and 3297 for increased liver weights and increased skeletal
variations, respectively.33 MOEs for worst-case exposure scenarios were 339 and 565 for increased
liver weights and increased skeletal variations, respectively.34 Overall, NICNAS concluded that the
derived risk estimates for DIDP indicate a low concern of these adverse effects under the exposure
conditions.35 This report is the basis for the current lack of a restriction for DIDP in children's toys and
childcare articles in Australia.36
Environment Canada and Health Canada -
Environment Canada and Health Canada have conducted a risk evaluation of DIDP.37 The report
identified three critical systemic effects after oral exposure to DIDP: liver weight increase in male rats
accompanied with histological changes at the highest dose in short term studies (300 mg/kg bw/day
was a NOAEL in females and LOAEL in males), liver weight increase accompanied with histological
changes in subchronic studies in the dog (NOAEL = 15 mg/kg bw/day) and histopathological changes
in liver of male rats in chronic studies (LOAEL = 22 mg/kg bw/day).38 Canada also evaluated the
potential evidence of any association between DIDP and health outcomes in humans and found no
evidence of an association with changes in sex hormone levels, anogenital distance, birth measures,
preterm birth and gestational age and pregnancy loss.39 Canada derived exposure estimates for DIDP
from available biomonitoring data, including measured levels of DIDP in dust, food and plastic items,
with male children 6-11 years identified as the highest exposed group and infants 6 months to 4 years
30 Australian Government National Industrial Chemicals Notification and Assessment Scheme (NICNAS). 2015. Diisodecyl
phthalate and Di-n-octyl phthalate. Existing Chemical Hazard Assessment Report. May 2015.
httpsi//www.nicnas.gov.au/ data/assets/word doc/0004/34843/PEC39-Diisodecvl-phthalate-and-Di-n-octvl-
phthalate.docx [hereafter "NICNAS 2015"].
31 Id. pp. 2 & 40.
32 Id. pp. 3, 16 & 17.
33 Id. pp. 43.
34 Id.
35 Id. p. 44.
36 Australia NICNAS Chemical Information Factsheet on DIDP. https://www.nicnas.gov.au/chemical-
information/factsheets/chemical-name/diisodecvl-phthalate-didp-and-di-n-octvl-phthalate-dnop. See "Report
recommendations.".
37 Environment Canada and Health Canada State of the Science Report. 2015. Phthalates Substance Grouping: Long-
chain Phthalate Esters, 1,2-Benzenedicarboxylic acid, diisodecyl ester (diisodecyl phthalate; DIDP) and 1,2-
Benzenedicarboxylic acid, diundecyl ester (diundecyl phthalate; DUP). http://www.ec.gc.ca/ese-
ees/default.asp?lanq=En&n=D3FB0F30-1 [hereafter "Canada SOS 2015"]. See also Environment Canada and Health
Canada. 2017. Draft Screening Assessment Phthalate Substance Grouping: Sections 9 and 10. http://www.ec.gc.ca/ese-
ees/default.asp?lang=En&n=1 E5B3C [hereafter "Canada 2017"].
38 Canada SOS 2015, note 37, sections 9.2.2.5.2 & 9.2.2.5.3; Canada 2017, note 37, Table 9-47.
39 Canada 2017, note 37, Table 9-49.
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old identified as the subpopulation with the highest exposure from dust and food. Using the oral LOAEL
of 22 mg/kg bw/day (histopathological changes in male rat liver in chronic studies), Canada derived
MOEs (central tendency and upper bound) for all possible age groups. Upper bound MOEs were 10,185
for infants 0-18 months (exposure to plastic articles), 76660 for children 6 months to 4 years (food and
dust, oral), 5000 for male children 6-11 years (95th percentile aggregate exposure from NHANES
biomonitoring data), and 4490 for female adults 20+ years (95th percentile aggregate exposure from
NHANES biomonitoring data).40 Overall, the Canadian evaluation concluded that the MOEs "are
considered adequate to account for uncertainties in the exposure and health effects databases and
further, protective of potential developmental and reproductive effects of DIDP toxicity not only in males,
but also in females as well as effects in other organ systems. These MOEs are also considered
adequate as they address potential carcinogenicity of DIDP that could occur at higher doses".
Regarding the use of DIDP in non-PVC applications like adhesives, sealants, and coatings, the
Canadian evaluation concluded that "exposure would not be considered to be of concern for human
health" based on low dermal absorption of DIDP in rats (1-4%), evidence that human skin is less
permeable than rat skin to phthalate diesters, low skin retention in humans compared to rat (3 to 6-fold
lower in humans), low tissue distribution with no accumulation, and rapid excretion (section 9.3.3).
Other Information -
The manufacturer, through the ACC HPP, notes that DIDP is listed as "known to the state of California
to cause reproductive toxicity" under California's Proposition 65.41 California's Office of Environmental
Health Hazard Assessment (OEHHA) based this listing the conclusion by the National Toxicology
Program's Center for the Evaluation of Risks to Human Reproduction (NTP-CERHR) that DIDP causes
developmental toxicity.42 According to the NTP-CERHR report, two prenatal toxicity studies of DIDP in
rats showed evidence of an increase in skeletal variations, while two 2-generation dietary reproductive
toxicity studies showed some evidence of an effect on postnatal survival and growth.43 However, it is
important to note that while the NTP-CERHR report acknowledges some evidence of developmental
effects in rats, it concludes that DIDP does not affect reproduction in rodents.44 Taking into
consideration the hazards of DIDP identified in rats and potential for exposure in humans, the NTP-
CERHR report concluded that "there is minimal concern for developmental effects in fetuses and
children" and that,"there is negligible concern for reproductive toxicity in exposed adults."45
Each of the studies reviewed in the 2003 NTP-CERHR report were also reviewed in the more recent
risk evaluations of DIDP by the US CPSC, European Union, Australia NICNAS and Environment
Canada/Health Canada. As summarized above, none of those agencies found concern for human
developmental or reproductive risk. For example, the US CPSC CHAP summarized developmental and
reproductive studies by noting, "[T]the CPSC calculated an [acceptable daily intake (ADI)] of 0.4 mg/kg-
day using the lowest developmental NOAEL of 40 mg/kg-day for DIDP-induced supernumerary ribs.
40 Canada SOS 2015, note 37, Table 9.23.
41 OEHHA 2007. Notice to Interested Parties: Chemical Listed Effective April 20, 2007 As Known To The State Of
California To Cause Reproductive Toxicity. https://oehha.ca.gov/media/downloads/proposttion~
65/chemicals/42007notice20diisodecvl20phthalate.pdf
42 Id. p. 1. See National Toxicology Program. 2003. NTP-CERHR Monograph on the Potential Human Reproductive and
Developmental Effects of Di-lsodecyl Phthalate (DIDP). NIH Publication No. 03-4485. https://www.cpsc.gov/s3fs-
public/nihDIDPQ42QQ3.pdf [hereafter "NTP-CERHR 2003"].
43 NTP-CERHR 2003, note 42, pp. 1-2 & II-24-25 (Table 5)
44 Id. p. 2.
45 Id. p. 3.
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Three well-conducted rat studies suggest that oral DIDP exposure is not associated with reproductive
toxicity at the levels tested."46 Using an even lower point of departure (POD) of 15 mg/kg bw/day (liver
effects with chronic dietary exposure in rats), the CHAP derived MOEs ranging from 2500 to 10000 for
median exposures and 586 to 3300 for exposures in the 95th percentile.47 These MOEs clearly indicate
no concern for developmental risk in humans with exposure to DIDP and are the basis for the US
CPSC's ruling lifting the interim restriction on the use of DIDP in children's toys and childcare articles.48
Overall, we conclude that the California Proposition 65 listing of DIDP for reproductive toxicity is not
relevant to the requested TSCA risk evaluation of DIDP.
To the best of our knowledge, no hazard or risk evaluation of DIDP has been conducted by the Agency
or the FDA since the 2012 Phthalate Action Plan was issued. We have included a reference to a publicly
available FDA investigation of levels of plasticizers (including DIDP) present in PVC articles authorized
as food contact materials in Appendix C (see Carlos et al. 2018).
Information relevant to the exposure potential of DIDP -
According to the 2014 update to the TSCA Work Plan, DIDP is assigned an exposure score of 3 (high),
based its common use as a plasticizer in PVC with industrial, commercial and consumer applications.
The US Centers for Disease Control and Prevention (CDC)'s National Health and Nutrition Examination
Survey (NHANES) has reported urinary levels of DIDP metabolites for the US population from 1999 to
2016.49 50 These data have served as the basis for recent risk evaluations of DIDP by regulatory
Agencies including the US CPSC and Environment Canada/Health Canada. These values represent a
snapshot of DIDP exposure in the general population from various sources (industrial, commercial, and
consumer) across a wide range of age, gender and race, and are reflective of the average
production/import volume of DIDP in the United States.
The NHANES database only provides biomonitoring information from ages 6 and above. The
manufacturer, through the ACC HPP, notes that the US CPSC CHAP (see footnote 9) utilized
biomonitoring data from the Study for Future Families (SFF)51 to estimate exposure to infants from 2 to
36 months, as well as estimating prenatal and postnatal measurements from their mothers.52 However,
the manufacturer, through the ACC HPP, advises that the SFF data be interpreted with caution as the
data only track DIDP exposures from 1999-2005 and may not necessarily reflect current exposures.
46 CHAP 2014, note 18, p. 104.
47 Id. p. 104
48 CPSC Phthalate Rule, note 9, p. 49968.
49 Data through the 2013-2014 NHANES cycle are presented in CDC's formal exposure report, which presents absolute
and creatinine-adjusted values at various percentiles and according to various subpopulations. CDC 2018. Fourth
National Report on Human Exposure to Environmental Chemicals. Updated Tables, March 2018, Volume One. pp. 489-
492 https://www.cdc.qov/exposurereport/pdf/FourthReport UpdatedTables Volumel Mar2018.pdf. [hereafter "NHANES
2005-2014"]"
50 Raw data for the 2015-2016 NHANES cycle are provided at
https://wwwn.cdc.gov/nchs/nhanes/search/datapage.aspx?Component=Laboratory&CycleBeginYear=2015 [hereafter
"NHANES 2015-16"]. These datasets need to be accessed using a SAS software viewer.
51 Swan, S; Calafat, A; Kruse, R; Lasley, B; Redmon, B; Sparks, A; Wang, C. Final Report: Study of Phthalates in
Pregnant Woman and Children (Study for Future Families (SFF)). EPA Grant Number: R829436.
https://cfpyb.epa.aov/ncer abstracts/index.cfm/fyseaction/displav.hiahlight/abstract/1950
https://www.cpsc.gov/s3fs-pyblic/SFF-Biomonitoririg-Data.pdf
52 See CHAP 2014, note 18, Appendix D.
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More recent summary data on mono (carboxy-isononyl) phthalate (MCiNP) DIDP metabolite collected
in The Infant Development and the Environment Study (TIDES) has been published.53'54 According to
the study authors, TIDES is a prospective cohort study of phthalate metabolites in urine samples of
pregnant women over 18 years old and <13 weeks pregnant, recruited from 2010-2012 and collected
in the first, second and third trimesters. Mean urinary concentrations of MCiNP (ng/mL) for each
trimester have been published for a limited dataset (N = 167-168).55 Mean values were well below the
90th percentile for all age groups 20 years and older and all females (regardless of age) reported for
the US population from NHANES, suggesting that the NHANES data is an appropriate surrogate for
estimating potential prenatal exposures to DIDP.
Limited data on urinary levels of DIDP metabolites are available for occupational workers and are
referenced in Appendix C. For example, in one study, levels of DIDP metabolites were assessed in
spot urine samples of 5 employees in a car manufacturing plant in German, refinishing plastisol seam
sealants.56 The refinishing was performed at room temperature with a brush or with fingers. Creatinine-
adjusted urinary levels of mono-(carboxylnonyl) phthalate (MCNP) ranged from 1.0-7.1 |jg/g for pre-
shift workers (median - 2.5 |jg/g) and 0.8-8.7 |jg/g for post-shift workers (median - 5.3 |jg/g). Although
the sampling period was not provided in the paper, the upper range of MCNP was similar to the 90th
percentile reported by NHANES for the US population ages 20 years and older between 2005 and
2014.57 Thus, it can be inferred that the higher percentile ranges of the NHANES dataset can be used
as an upper bound estimate or worst-case estimate of exposures to DIDP across the population,
including occupational workers.
One use that the manufacturer, through the ACC HPP, is requesting for risk evaluation is the use of
DIDP in children's toys, including those that could be placed in a child's mouth, and childcare articles.
Compared to DINP, evaluations of potential exposures of children to DIDP in toys is limited. Some
regulatory agencies (for example, the European Chemicals Agency) have assumed that the level of
exposure to DIDP from toys would be equivalent to that of DINP.58 However, published estimates of
DIDP exposure from toys are considerably lower than those for DINP.59 Several phthalate migration
and PVC toy mouthing studies in infants are available and have been reviewed by other regulatory
agencies. In one study, the US CPSC conducted an assessment to identify the types and migration of
plasticizers used in component parts of various children's toys and childcare articles on the market after
2008.60 The CPSC identified 129 component parts from 63 samples, 38 of which were composed of
53 Swan, S.H., T.S.T. the, S. Sathyanarayana, T.S.T. the, E.S. Barrett, T.S.T. the et al.: First trimester phthalate exposure
and anogenital distance in newborns. Human Reproduction 30(4): 963-972 (2015).
https://academic.oup.eom/humrep/article/30/4/963/613595.
~54 Martino-Andrade AJ, Liu F, Sathyanarayana S, Barrett EES, Redmon J, Nguyen RH, Levine H, Swan SH; TIDES Study
Team. Timing of prenatal phthalate exposure in relation to genital endpoints in male newborns. Andrology. 2016
Jul;4(4):585-93. doi: 10.1111/andr.12180. Epub 2016 Apr 7. https://www.ncbi.rilm.nih.aov/pybmed/27062102
55 Id. p. 588 (Table 1).
56 Koch, H.M., A. Haller, T. WeiG, H.-U. Kafferlein, J. Stork, and T. Bruning: Phthalate exposure during cold plastisol
application—a human biomonitoring study. Toxicology Letters 213(1): 100-106 (2012).
57 See NHANES 2005-2014, note 49, pp. 489-492 for urinary MCNP (in |jg/g creatinine) for the 2005/2006 to 2013/2014
NHANES cycles.
58 ECHA 2013, note 26, p. 202.
59 Compare Table 4.65 and 4.66 in id. pp. 204-205.
60 US CPSC (2010). Phthalates and Phthalate Substitutes in Children's Toys, https://www.cpsc.gov/s3fs-
public/phthallab.pdf
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PVC.61 DIDP was not identified in any of the items.62 DINP was only found in 1 item; the majority of the
items contained other plasticizers such as di-2-ethylhexyl terephthalate (DOTP) and 1, 2-
cyclohexanedicarboxylic acid, di-isononyl ester (DINCH).63
All documents and data summarized above are referenced in Appendix C of this request for the
Agency's review.
Information relevant to the persistence and bioaccumulation of DIDP -
According to the Agency's 2012 Phthalates Action Plan and 2014 TSCA Work Plan, DIDP exhibits low
toxicity to aquatic organisms and is ranked low for persistence and bioaccumulation.64
The most relevant and thorough ecological hazard and risk evaluations of DIDP are available in the
European Union (EU) 2003 risk assessment and Environment Canada and Health Canada's 2015 State
of the Science Report on long-chain phthalate esters.65 Tables 7-3 and 7-4 of Canada's State of the
Science report provide an extensive summary of the biodegradation data available for DIDP. Canada
summarizes that DIDP is rapidly biodegraded in aerobic conditions (and even under conditions of low
oxygen), with 68% removal within 1 day and 90-100% removal of parent substance within 10-28 days.66
With respect to bioaccumulation, Canada states, "Empirical bioconcentration factors (BCFs) of <14 and
147 L/Kg wet weight and biota-soil/sediment accumulation factors (BSAFs) of 0.015 and 0.16 suggest
that DIDP has low potential to bioaccumulate in aquatic and terrestrial organisms."67
A detailed review of the biodegradation of DIDP is also available in the 2003 EU risk assessment
report.68 Overall, the data support Canada's conclusion that DIDP is readily biodegraded and is hence
unlikely to persist in the environment.69 Bioaccumulation data for DIDP itself were limited, but overall
the EU report supports Canada's finding that DIDP has "low bioaccumulation and biomagnification
potential".70
Test results and robust summaries pertaining to DIDP's persistence and bioaccumulation are
referenced in Appendix C under the data sets submitted to the European Chemicals Agency.
Potentially exposed or susceptible subpopulations relevant to the EPA risk evaluation -
The Agency has indicated that it considers children and the developing fetus as the susceptible
subpopulations for which the health risks of DIDP should be assessed.71 The CDC report of NHANES
data on urinary metabolites of DIDP (reported as geometric means and selected percentiles) is stratified
by gender (males and females), race/ethnicity (Mexican American; Non-Hispanic Black; Non-Hispanic
White) and age group (6-11 years, 12-19 years and >20 years).72 Additional refinements can be made
by directly accessing the NHANES database to obtain relevant information on DIDP exposures in the
subpopulation that the Agency considers to be most susceptible, children and women of childbearing
61 Id. p. 4.
62 Id.
63 Id.
64 2012 Action Plan, note 11, pp. 5-6; 2014 Work Plan, note 16, p. 12.
65 ECB 2003, note 25, pp. 23-106; Canada SOS 2015, note 37, Sections 7 & 8.
66 Canada SOS 2015, note 37, Section 7.2.1.
67 Id. section 7.3.
68 ECB 2003, note 25, pp. 23-26.
69 Canada SOS 2015, note 37, Synopsis.
70 Id.; ECB 2003, note 25, p. 27-33
71 2012 Action Plan, note 11, pp. 8.
72 NHANES 2005-2014, note 49, pp. 489-492
Page 11 of 20
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age. As earlier mentioned, NHANES does not include data on infants and children <6 years of age.
The SFF data, with a smaller subset of infants (2-37 months) may be considered as a surrogate, with
caution, as noted previously.73
With respect to evaluation of DIDP exposure from mouthing toys and childcare articles (the worst-case
exposure scenario for children), minimal data is available and certain regulatory agencies (like the
European Chemicals Agency) have extrapolated from data available for DINP. These are summarized
in the exposure section.
Potential for storage of chemical substance near significant sources of drinking water,
including storage facility location and nearby drinking water source(s) -
DIDP is used primarily as a plasticizer in finished flexible PVC products. As the conditions of use in
Appendix B (Production and Use) involve the end use products into which DIDP is incorporated, none
include storage of DIDP next to significant sources of drinking water or otherwise. Any significant
storage of the chemical is likely restricted to manufacturing and/or storage terminals for DIDP. A
detailed evaluation of the fate and behavior of DIDP in environmental media, including water, has been
conducted by Environment Canada and Health Canada.74 A summary of a Level III fugacity modeling
with a detailed evaluation of partitioning, transport, degradation and transformation processes for DIDP
when released into environmental media, is available.75 Canada concludes that a high solid phase
partition coefficient (log Kow >8-12) and low water solubility (7.1 * 10~7 to 1.2 mg/L at 20 to 25 °C) for
DIDP suggests that DIDP released into water will distribute primarily into sediment (90-94%), with <20%
expected to remain in the water column.76 Due to low vapor pressure (4.97 x 10"7 to 3.77 x 10~2 Pa at
25 °C), 0% of DIDP released into water is expected to distribute to air.77 With respect to release into
soil, the high solid phase partition coefficient, combined with low water solubility, suggests that the
substance sorbs strongly to organic matter in soil, and will have low mobility.78 The model prediction of
low mobility for DIDP means that it is unlikely to leach through soil to groundwater or a surface source
of drinking water.
According to the Canadian report, and as summarized above, DIDP is rapidly biodegraded in aerobic
aqueous environments, with 68% of the parent substance removed within 1 day and 90-100% removed
within 105-28 days.79 Overall, the physico/chemical properties of DIDP (low water solubility and high
partition coefficient/high hydrophobicity) are such that it is rapidly degraded in water and primarily
partitions to suspended particulate fraction of surface waters in the event of spillage into water. In the
event of spillage into a water source that serves as a source of drinking water, since DIDP tends to
sorb to sediment particles, treatment with flocculants and filters would separate out the DIDP prior to
distribution in the drinking water system. In the event of soil spillage, the high partition coefficient and
low mobility of DIDP suggests that it is primarily adsorbed to soil and unlikely to migrate to ground
water. Therefore, should there be a spill of DIDP into water or soil, the potential for significant
contamination of sources of drinking water is very low.
73 See note 51 and associated text.
74 Canada SOS 2015, note 37, Section 7.
75 Id. Table 7-1.
76 Id. Section 7.1.
77 Id.
78 Id.
79 Canada SOS 2015, note 37, Section 7.2.1.
Page 12 of 20
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In that respect, the manufacturer, through the ACC HPP, is aware of the following:
All manufacturing and storage locations have developed Spill Prevention Control & Countermeasure
(SPCC) plans prepared in accordance with requirements and guidelines set forth in 40 CFR 112. The
purpose of this SPCC Plan is to establish procedures and methods in accordance with best
management practices to prevent and control the discharge of pollutants resulting from a spill event
into navigable waters.
DIDP production volume -
DIDP production volumes for 2012-2015 for both DIDP CASRNs, as reported in the Agency's Chemical
Data Reporting database, are provided in Appendix B of this request. No significant changes in
production volume were observed for the reported years.
Addendum
As noted above, the manufacturer, through the ACC HPP, believes that, to the best of our knowledge,
it has provided the Agency with all the existing information that is relevant to whether DIDP, under the
conditions of use identified herein, presents an unreasonable risk of injury to health or the environment.
As all of the information is publicly available, HERO database or bibliographic citations are provided,
rather than actual copies of the information. The manufacturer, through the ACC HPP, commits to
provide to the Agency any referenced information upon request.
Certification
I certify, on behalf of the American Chemistry Council High Phthalates Panel, that to the best of my
knowledge and belief:
The ACC HPP represents major companies that manufacture, compound, convert, or import DIDP, the
chemical substance identified for risk evaluation.
All information provided in the notice is complete and accurate as of the date of the request.
On behalf of the ACC HPP, I have either identified or am submitting all information in my possession
and control as ACC HPP manager, and a description of all other data known to or reasonably
ascertainable by me as required for this request under this part. I am aware it is unlawful to knowingly
submit incomplete, false and/or misleading information in this request and there are significant criminal
penalties for such unlawful conduct, including the possibility of fine and imprisonment.
Sincerely,
Sdem (fatmely
Eileen Conneely
on behalf of the American Chemistry Council
High Phthalates Panel
Page 13 of 20
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Certification
I certify that to the best of my knowledge and belief:
ExxonMobil Chemical Company manufactures the chemical substance identified for risk evaluation.
All information provided in the notice is complete and accurate as of the date of the request.
I have either identified or am submitting all information in my possession, control, and a description of
all other data known to or reasonably ascertainable by me as required for this request under this part.
I am aware it is unlawful to knowingly submit incomplete, false and/or misleading information in this
request and there are significant criminal penalties for such unlawful conduct, including the possibility
of fine and imprisonment.
Sincerely,
"Tit, "David
M. David Adenuga
on behalf of ExxonMobil Chemical Company
Page 14 of 20
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APPENDIX A - SUBSTANCE IDENTITY INFORMATION
DIISODECYL PHTHALATE (DIDP)
Name and substance identifiers
The substance "di-isodecyl phthalate" is described by two CAS numbers based on the composition of
the alkyl side chains.
Table 1: Substance Identity
CAS
Number
Systematic Name
EPA Registry
Name
Molecular
formula
Molecular
weight range
(g/mol)
26761-40-
0*
1,2-benzenedicarboxylic acid,
1,2-diisodecyl ester
Diisodecyl
phthalate
C28H46O4
446.67
68515-49-
yj **
1,2-Benzenedicarboxylic acid,
di-C9-n-branched alkyl esters,
Cio-rich
Cio-Rich di-C9-n-
branched alkyl
phthalates
C28H46O4***
447
* EPA Substance Registry Service
** EPA Substance Registry Service
*** EU REACH Chemical Safety report - DIDP (CASRN 68515-49-1)
Structure1
V 0'
Figure 1: CAS Number-26761-40-0
Figure 2: CAS Number- 26761-40-0
O CqHi n-i
O CnH2n^
n = 9 to 11
Figure 3: CAS Number - 68515-49-1 (Source: EU REACH Chemical Safety Report)
Table 2: Other Names Used (European Chemicals Agency [ECHA] REACH information)
CAS
Number
Regulatory Process Names
Trade Names
IUPAC Names
1 European Chemicals Bureau. 2003. European Union Risk Assessment Report on 1,2- benzenedicarboxylic acid, di-C9-
11-branched alkyl esters, C10-rich and di-"isodecyl" phthalate (DIDP). https://echa.europa.eu/documents/10162/190cf4c4-
b597-4534-9b71-f79fce55050b [hereafter "ECB 2003"].
-------
EINECS
Number
26761-
40-0
247-977-
1*
o Di-"isodecyl" phthalate
o di-"isodecyl" phthalate
o Di-"isodecyl" phthalate
(DIDP)
o DIDP
o 1,2-Benzenedi-carboxylic
acid, diisodecyl ester
o 1,2-bis(8-methylnonyl)
benzene-1,2-dicarboxylate
o bis(7,7-dimethyloctyl)
phthalate
o di-"isodecyl" phthalate
o Diisodecyl phthalate
o Diisodecyl Phthalate (mixture
of branched chain isomers)
68515-
49-1
271-091-
4**
o 1,2-Benzenedicarboxylic
acid, di-C9-11-branched
alkyl esters, C10-rich
o 1,2-Benzenedicarboxylic
acid, di-C9-11-branched
alkyl esters, C10-rich
o JAYFLEX
DIDP-E
o 1,2-Benzenedicarboxylic
acid di(C=9-11) branched
alkyl esters, (C=10)-rich
o 1,2-Benzenedicarboxylic
acid, di-C9-11-branched
alkyl esters, C10-rich
o bis(8-methylnonyl) phthalate
o Didodecylphthalate, DIDP
NR - Not registered under EU REACH
*ECHA substance information - https://echa.europa.eu/substanee~infQrmation/~/substaneeinfo/100.043.601. Note, this
substance is not registered under EU REACH.
**ECHA substance information - https://echa.europa.eu/substance-information/-/substanceinfo/100.064.609
Table 3: Other Names Used (US NLM TOXNET data)
CAS Number
Synonyms
26761-40-0*
1,2-Benzenedicarboxylic acid, diisodecyl ester;
Bis(isodecyl) phthalate;
Bis(isodecyl)phthalate;
BRN 2171889;
CCRIS 6194;
Di(i-decyl) phthalate;
Didp;
DIDP (plasticizer);
Diisodecyl phthalate;
HSDB 930;
Palatinol Z;
Phthalic acid, bis(8-methylnonyl) ester;
Phthalic acid, diisodecyl ester;
Plasticized ddp;
PX 120;
Sicol 184;
UNII-WF93T741QI;
Vestinol DZ
68515-49-1**
1,2-Benzenedicarboxylic acid, di-C9-11-branched alkyl esters,
C10-rich;
Page 16 of 20
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C10-Rich di-C9-11-branched alkyl phthalates;
Diisodecyl phthalate;
1,2-Benzenedicarboxylic acid, di-C9-11-branched alkyl esters,
C10-rich;
Di(C9-C11) branched alkyl phthalate;
Phthalic acid, di-C9-11-branched alkyl esters, C10-rich
*httpsi//chem. nlm.nih.gov/chemtdplus/rn/26761~4Q~Q
** https://chem.nlm.nih.gov/chemidplus/rn/68515-49-1
N/A - No number identified.
Considerations for Evaluating both CAS Numbers as a Single Substance2
As shown in Table 1, two di-isodecyl phthalate (DIDP) products are identified by two different CAS
numbers. Both substances are manufactured from the same feed, through an identical olefin
oligomerization process and through similar oxo alcohol manufacturing and phthalate esterification
processes. According to the EU risk assessment report for DIDP, both CAS numbers represent complex
substances that contain mainly Cio-branched isomers (see footnote 1). The structure of DIDP illustrated
in figures 1 and 2 represent CAS number 26761-40-0. DIDP identified by CAS number 68515-49-1
refers to a multi-constituent substance comprised of C9-C11 (Cio-rich) branched dialkyl phthalate esters,
illustrated in figure 3. The C9-, C10-, and Cn-dialkyl groups have methyl branching, which on the average
includes 2 methyl branches per molecule, typically found on the 2nd, 3rd and/or 4th carbons of the alkyl
chain closest to the aromatic ring. Both CAS numbers contain mainly C10 dialkyl phthalate esters,
having identical molecular formula C28H46O4 (with a molecular weight of approximately 446.7 Da).3
DIDP is manufactured by the esterification of phthalic anhydride with C9-C11 (Cio-rich) branched
alcohols, with a final concentration range comprised of >70% C10 isomers and <20% each of C9 and
C11 isomers. Both CAS numbers are considered to be fully interchangeable, and have been considered
to possess toxicologicallv equivalent properties and evaluated as a single substance by other regulatory
agencies.4' 5' 6' 7
2 See note 1.
3 Chronic Hazard Advisory Panel (CHAP) on Phthalates. 2010. Toxicity review of DIDP [page 2] -
https://www.cpsc.gov/s3fs-public/toxicttvDlDP.pdf
4 Australia NICNAS (2015): Priority Existing Chemical Assessment Report 39 - Diisodecyl phthalate and Di-n-octyl
phthalate - https://www.nicnas.gov.au/ data/assets/word doc/0004/34843/PEC39-Diisodecvl-phthalate-and-Di-n-octvl-
phthalate docx
5 Environment Canada and Health Canada State of the Science Report. 2015. Phthalates Substance Grouping: Long-
chain Phthalate Esters, 1,2-Benzenedicarboxylic acid, diisodecyl ester (diisodecyl phthalate; DIDP) and 1,2-
Benzenedicarboxylic acid, diundecyl ester (diundecyl phthalate; DUP). http://www.ec.gc.ca/ese-
ees/default.asp?lang=En&n=D3FB0F30~1 [hereafter "Canada SOS 2015"].
6 See note 1.
7 See note 3.
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APPENDIX B - PRODUCTION AND USE
DIISODECYL PHTHALATE (DIDP)
Production volume
According to the 2015 US EPA Chemical Data Reporting (CDR) database1, between 1 and 260 million
pounds of DIDP was imported or manufactured in the United States as follows (note that this volume
has remained constant since 2012):
Table 1: US DIDP Production volumes for 2012 to 2015, by CAS Number
Reporting Year
2012
2013
2014
2015
Total Aggregate
Production Volume (lbs.)
CASRN
26761-40-0
1 -10
million
1 -10
million
1 - 10
million
1 - 10
million
CASRN
68515-49-1
100-250
million
100-250
million
100-250
million
100-250
million
2016 CDR data reported for CASRN 26761-40-0 indicates that it is used for industrial and commercial
applications.2 Listed industrial uses include incorporation into formulation, mixture, or reaction product
for making adhesives and sealant chemicals, petroleum lubricating oil and grease manufacturing and
as a plasticizer. One commercial use is listed in the CDR report, for use in manufacturing adhesives
and sealants. With respect to CASRN 68515-49-1, the 2016 CDR data reports use for industrial,
consumer and commercial applications. All listed applications involve incorporation into an article or
into formulation, mixture, or reaction product for manufacturing adhesives and sealants, paints and
coatings, plastic products and resins (as a plasticizer).
Uses
For the purpose of this document, the term DIDP represents Chemical Abstract Service Registry
Numbers (CASRNs) 26761 -40-0 and 68515-49-1. However, it should be noted that the CASRN 26761 -
40-0 is not currently registered under EU REACH and we are not aware of any commercial production
of the material. DIDP is used primarily as a plasticizer to impart flexibility to polyvinyl chloride (PVC) in
consumer and industrial applications.3 4 5 6 These PVC products are used in automotive products such
as upholstery and interior finishes (e.g. synthetic leather for car interiors), interior PVC skins
(dashboards and shift boot covers), window glazing (urethane glass bonding adhesives and PVC
window encapsulate), body-side molding, automotive undercoating, molded interior applications,
insulation for wire and cable and wire harnesses and synthetic lubricants and engine oils. DIDP-
1 US EPA Chemical Data Access Tool (CDAT). httpsi//chemview.epa.qov/chemview. Last accessed - December 12,
2018.
2 CDR defines "industrial use" as use at a site at which one or more chemicals or mixtures are manufactured (including
imported) or processed. "Commercial use" means the use of a chemical or a mixture containing a chemical (including as
part of an article) in a commercial enterprise providing saleable goods or services. "Consumer use" means the use of a
chemical or a mixture containing a chemical (including as part of an article, such as furniture or clothing) when sold to or
made available to consumers for their use. - Public database 2016 chemical data reporting (Data last updated 12/9/2018).
Washington, DC: US Environmental Protection Agency, Office of Pollution Prevention and Toxics.
3 American Chemistry Council (ACC) (2018). Phthalates: High phthalates uses and applications.
https://phthalates.americanchemistrv.com/Hiqh~Uses-and~Applications.html
"4 IHS Markit. (2018). Chemical Economics Handbook: Plasticizers, pp. 42. 4 May 2018.
5 European Plasticisers (2018). Plasticisers Information Center: Orthophthalates.
https://www.plasticisers.org/plasticisers/orthophthalates/
6 European Chemicals Agency (ECHA) (2010). Review of New Available Information for di-isodecyl phthalate (DIDP). p. 4.
https://echa.europa.eu/documents/10162/13641/didp echa review report 2010 6 en.pdf
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plasticized PVC is also used in building and construction, particularly in adhesives and sealants,
electrical wire coating, vinyl tiles, resilient flooring, PVC-backed carpeting, pool liners, roofing and wall
coverings. Other uses include use flexible tubes, profiles, hoses, and inks.
The most recent assessment of United States (US) consumption of DIDP (Figure 1) indicates that the
largest share is used for building wire and power cable jacketing and electrical insulation and appliance
cords. Other uses include jacketing for communications, electronics and automotive wire, automotive
interiors and undercoats and coated fabrics.
Film and sheet
Automotive
protective
undercoatings
r Wire and cable
insulation and jacketing
Other
Figure 1: US Consumption ofdiisodecyl phthalate (percent) - 2017 (Source - IHS Markit.
Plasticizers. 4 May 2018). Note, film and sheet applications include use in roofing, wall coverings,
pool liners etc.).
Prior regulations restricting use
From 2009 to 2017, there were certain restrictions on DIDP use in children's toys and childcare articles.
In 2008, the United States Congress passed the Consumer Product Safety Improvement Act (CPSIA)
that placed an interim restriction on the use of DIDP in children's toys that can be placed in a child's
mouth and childcare articles at concentrations no greater than 0.1%7. On the 27th of October 2017, the
US Consumer Product Safety Commission (CPSC) issued a final ruling in the Federal Register (82 FR
49938) that lifted this restriction on the basis that DIDP is not antiandrogenic and a continued prohibition
is not necessary to ensure a reasonable certainty of no harm to children, pregnant women, or other
susceptible individuals with an adequate margin of safety.8
Intended uses requested for evaluation
o DIDP Manufacturing
o DIDP use as a general purpose plasticizer for PVC used in the following applications;
o Building and construction - electrical wire coating, vinyl tiles, resilient flooring, PVC-
backed carpeting, wall coverings, roofing etc.
o Automotive - upholstery and interior finishes (e.g. synthetic leather for car seats, interior
PVC skins for dashboards and shift boot covers), window glazing, body-side molding,
7 Consumer Product Safety Act of 2008 - https://www.cpsc.gov/s3fs-public/pdfs/blk pdf cpsia.pdf
8 US Consumer Product Safety Commission (CPSC) (2017). Prohibition of Children's Toys and Child Care Articles
Containing Specified Phthalates. https://www.qpo.gov/fdsvs/pkq/FR-2017-10-27/pdf/2017-23267.pdf
Page 19 of 20
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automotive undercoating, molded interior applications, insulation for wire and cable and
wire harnesses.
o Other consumer applications - flexible tubes, hoses and profiles etc.
o Non-PVC applications - inks, adhesives, sealants and paints, synthetic lubricants and
engine oils.
o Use in PVC for children's toys and childcare articles
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