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Department of Toxic Substances Control Cal/EPA
Connections between Environmental Chemistry Research and DTSC’s Safer Consumer Products
Program: A case study on Quaternary Ammonium Compounds (QACs).
Anne-Cooper Doherty, Ph.D.
Safer Consumer Products Program
April 8, 2015
Outline
DTSC’s Safer Consumer Products Program
SCP program research needs
Case Study: QACs research and SCP research needs
2
CALIFORNIA SAFER CONSUMER PRODUCTS PROGRAM (SCP)
3
Basics: The Goal: Safer consumer products
Asks the questions: • Is this chemical necessary? • Is there a safer alternative?
Greater market opportunities
for innovative companies
Basics: How the SCP Program Works
5
Candidate Chemicals List
Priority Products
Alternatives Selection
4. Regulatory Response
3. Alternatives Analysis
2. Products (Product-Chemical Combinations)
1. Chemicals
1100 Candidate Chemical Groups 23 Authoritative Lists referenced
• 8 exposure potential lists (NHANES, Cal Biomonitoring)
• 15 hazard trait lists
Exclusions
• Registered pesticides
• Prescription drugs
• Metabolite/breakdown products
• Radioactive chemicals
• Natural toxins
Updates with Authoritative Lists 6
>2,300 Chemicals http://www.dtsc.ca.gov/SCP/ChemList.cfm
Basics: Prioritization Principles for Picking Product/Chemical Combinations
Potential exposure to the Candidate Chemical(s) in the product
AND
Potential for exposures to contribute to or cause significant or widespread adverse impacts*
7 *adverse environmental impacts alone are sufficient
Initial 3 Priority Products Selected
8
Children’s Foam-Padded Sleeping Products containing TDCPP/TCEP
Paint Strippers containing Methylene Chloride
Spray Polyurethane Foam Systems with MDI
Next 3 Years: Priority Product Work Plan
Identify product categories for next 3 years
Provide market signals
Engage stakeholders, gather data
Identify potential Priority Products
9
Policy priorities
Clear exposure pathways (dermal, inhalation, etc.)
Biomonitoring results
Chemicals found in indoor air monitoring
Sensitive subpopulations – children, workers
Aquatic resource impacts and/or found in water quality monitoring
10
7 Product Categories
1. Beauty, Personal Care and Hygiene Products
2. Building Products - Paints, Adhesives, Sealants, Flooring
3. Household/Office Furniture/Furnishings
4. Cleaning Products
5. Clothing
6. Fishing and Angling Equipment
7. Office Machinery Consumable Products 11
SCP Research Needs
Monitoring data (including California specific) • Aquatic environments, indoor environments,
sensitive subpopulations
Contaminant source information • Particularly product specific source information
• Changes in use, new contaminants, supporting data
Environmental fate of contaminants
Methods and approaches for filling data gaps*
Methods and approaches for comparing chemicals with varying amounts of data*
12
About Me
Joined DTSC in August of 2014
Completed a PhD in Environmental Chemistry at Stony Brook University • Studied the occurrence, fate and transport of
quaternary ammonium compounds (QACs)
• Researched the use of QACs as sewage tracers
• Used QACs for source allocation of a number of aquatic contaminants
13
QAC Research and SCP Research Needs
Monitoring data (including California specific) • Aquatic environments, indoor environments,
sensitive subpopulations
Contaminant source information • Particularly product specific source information
• Changes in use, new contaminants, supporting data
Environmental fate of contaminants
Methods and approaches for filling data gaps
Methods and approaches for comparing chemicals with varying amounts of data
14
A CASE STUDY: QACs
- Evidence for use of QACs (DTDMAC 18:18) as a sewage tracer
- Examples of the type of research that helps fill the SCP research needs
15
Acknowledgements
Bruce Brownawell, Stony Brook University
Xiaolin Li, Xiamen University
EPA STAR
New York Department of State
16
Sewage Tracers
Source specific contaminants or properties that can be used to characterize the extent and distribution of sewage impacts in aquatic environments
Particle reactive sewage tracers specifically track the distribution of particles that have been affected by sewage
Examples include a contaminant like silver or stable isotope ratios of C and N in organic matter
17
Particle Reactive Sewage Tracers
Assist in understanding: • intensity of sewage impacts
• transport of sewage affected particles
• contaminant source allocation
• the biogeochemistry of other chemical contaminants
• sediment transport and deposition
18
Desired Qualities of Particle Reactive Sewage Tracers
sewage is the dominant source
extremely particle reactive
large environmental concentrations, high sensitivity, low background levels
known time history
persistent in the environment being studied
19
Previously Used Sewage Tracers
Ag, LABs, fecal sterols
variable time histories and persistence reported
TAMs (trialkylamines, impurities in QACs)
20
TAMs
QACs as Sewage Tracers
Li and Brownawell measured high levels of QACs in U.S coastal waters
Proposed their use as stable, particle reactive sewage tracers
21
Quaternary Ammonium Compounds
- Permanently charged cations
- High production volume chemicals
- Uses:
- Personal care products
- Conditioners
- Disinfectants/anti-microbials
- Softeners/anti-statics
22
QACs
23
DADMAC : n=8,10
DTDMAC: n=12–18 ditallow dimethyl
alkyltrimethyl ammonium compounds
benzylalkyl dimethyl ammonium compounds
dialkyl dimethyl ammonium compounds
- Positive charge and hydrophobicity associated with the carbon side chains results in extremely particle reactive compounds
QAC Sediment Extraction method
0.10 g of freeze dried sediment
3 x 10mL extractions with acidic methanol in a heated sonication bath
Two part cleanup step: • LLE with chloroform
• Anionic exchange resin
HPLC-ToF-MS for analysis • Two dilutions needed
Li and Brownawell 2010, Lara-Martin et al 2010 24
QACs as Sewage Tracers
25
sewage is the dominant source
extremely particle reactive
large environmental concentrations, high sensitivity, low background levels
known, steady time history
persistent in the environment being studied
✔
✔
✔
26
QACs as Sewage Tracers
large environmental concentrations, high sensitivity, low background levels
known, steady time history
persistent in the environment being studied
✔
QACs: Previous Work
• A majority of sediment studies in the US done by Li and Brownawell
• Li and Brownawell (ES&T,2010)
27
88
Figure 3.1. Surface sediment sample locations in the NY/NJ Harbor Complex. Blue
squares indicates samples collected from Flushing Bay; red triangle indicates
samples collected near CSO outlets or CSO impacted Passaic River; black dots
indicate locations of all other sample collection sites.
Concentrations of QAC homologues and other organic
contaminants in 1998 NY/NJ REMAP Sediments (n=45)
TOC
(%)
PAH
(mg/g)
PCB
(mg/g )
NPEO
(mg/g)
QACs
(mg/g)
Minimum 0.19 n.d. n.d. 0.030 0.98
Maximum 10 91 2.5 78 110
Mean 3.6 5.8 0.15 6.1 34
Median 3.0 2.3 0.043 2.4 27
Study Site 1: Hempstead Bay, NY
28
Hempstead Bay Sample Sites
29
Sewage Treatment Plant
Flow
Bay Park STP 50 MGD
Long Beach STP 5 MGD
Lawrence STP 1.3 MGD
West Long Beach STP
0.6 MGD
QACs in Hempstead Bay
30
0
20,000
40,000
60,000
80,000
100,000
120,000
0 5 10 15 20 25
ΣQ
AC
s n
g/g
km from the BPO
QACs in Hempstead Bay
31
0
5,000
10,000
15,000
20,000
25,000
30,000
35,000
40,000
0 5 10 15 20 25
DT
DM
AC
18
:18
ng
/g
km from the BPO
DTDMAC 18:18 represents 40-60% of ƩQACs found in the samples.
Study Site 2: Long Island Sound
32
Long Island Sound Sample Sites
33
61
Figure 2.1. a) Locations of sediment grab samples taken in 2008 in Long Island Sound, NY and b)
sample locations from the East River and WLIS. Yellow dots represent stations from the 2008 transect,
orange dots represent samples from Li, 2009, and red dots represent sewage outfalls.
a)
b)
Long Island Sound
34
0
2000
4000
6000
8000
10000
12000
14000
16000
0 10 20 30 40 50 60 70 80
ƩQ
AC
s n
g/g
km from Tallman Island STP outfall
Long Island Sound
35
0
1000
2000
3000
4000
5000
6000
7000
0 10 20 30 40 50 60 70 80
DT
DM
AC
18
:18
ng
/g
km from Tallman Island STP outfall
DTDMAC 18:18 represents 40-50% of the ƩQACs found in the samples.
Triclosan vs. BACs
36 Pulse of the Bay, 2013, SFEI
0
50
100
150
200
250
300
350
400
450
500
0 10 20 30 40 50 60 70 80
ƩB
AC
s n
g/g
km from Tallman Island STP outfall
ƩBACs in Long Island Sound
0
1,000
2,000
3,000
4,000
5,000
6,000
7,000
0 5 10 15 20 25
ΣB
AC
s n
g/g
km from the BPO
ƩBACs in Hempstead Bay
QAC Research and SCP Research Needs
Monitoring data (including California specific) • Aquatic environments, indoor environments,
sensitive subpopulations
Contaminant source information • Particularly product specific source information
• Changes in use, new contaminants, supporting data
Environmental fate of contaminants
Methods and approaches for filling data gaps
Methods and approaches for comparing chemicals with varying amounts of data
37
QACs as Sewage Tracers
38
sewage is the dominant source
extremely particle reactive
large environmental concentrations, high sensitivity, low background levels
known time history
persistent in the environment being studied
What the literature says: lab studies
Lab biodegradation estimates suggest that QACs can be readily degraded under oxic conditions
Anoxic lab studies suggest much reduced biodegradation
Biodegradability ↓ as chain length ↑
Lab studies do not always = real world environment
39
QAC mass balances in sewage treatment plants
40
Clara et al., 2007
- Trialkyl methyl ammonium chloride - Dominant source to environment is thought to be as impurities in
QACs; similar time histories - decreases in the ratio of DTDMAC 18:18 to TAMAC 16:18:18 with
distance from the source would indicate preferential degradation or desorption of DTDMAC 18:18
Persistence: Comparison to TAMAC 16:18:18
41
0
50
100
150
200
0 5 10 15 20
km from Bay Park STP outfall
DTDMAC 18:18/TAMAC 16:18:18 in
HB
Sediment Cores
A way to understand the changes in environmental inputs of contaminants over time (decades)
Sediment cores from anoxic, depositional environments can preserve important information about historical inputs
42
43 1930
1940
1950
1960
1970
1980
1990
2000
2010
0 20 40 60
HB Core 3
DTDMAC 18:18/TAMAC
16:18:18
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 50 100
HB Core 11
DTDMAC 18:18/TAMAC
16:18:18
- decreases in the ratio of DTDMAC 18:18 to TAMAC 16:18:18 with depth in a core would indicate degradation of DTDMAC 18:18
Persistence: Comparison to other chemicals
Additional data for persistence
Matched cores over 20 years indicating no in situ degradation
Degradation experiments using Hempstead Bay sediment indicate no degradation for all but smallest QACs • Oxic and anoxic
44
QAC Research and SCP Research Needs
Monitoring data (including California specific) • Aquatic environments, indoor environments,
sensitive subpopulations
Contaminant source information • Particularly product specific source information
• Changes in use, new contaminants, supporting data
Environmental fate of contaminants
Methods and approaches for filling data gaps
Methods and approaches for comparing chemicals with varying amounts of data
45
QACs as Sewage Tracers
46
known time history
persistent in the environment being studied
DTDMAC 18:18 time history
First uses as fabric softeners in the mid to late 1950’s
Production peaked in the late 1980’s due to a 1991 voluntary phase out in Europe
• 2-8 mg/g DTDMACs found in sewage sludge
47
US International Trade Commission Data (ended in 1993)
0
10000
20000
30000
40000
50000
60000
70000
80000
90000
1960 1970 1980 1990 2000
DT
DM
AC
pro
du
ctio
n
(1000's
of
pou
nd
s)
year
DTDMAC 18:18 time history: Sediment Cores
A way to understand the changes in environmental inputs of contaminants over time (decades)
Sediment cores from anoxic, depositional environments can preserve important information about historical inputs
Now know that at least the biggest QACs are extremely persistent in anoxic, deposition environments
48
Cores Sampled – Hempstead Bay
49
50
Cores Sampled – Jamaica Bay
DTDMAC 18:18
51
0 20,000 40,000 60,000 80,000 100,000
JB Core 7
Hempstead Bay, NY Jamaica Bay, NY
0 5,000 10,000 15,000 20,000 25,000 30,000
HB Core 11
1935
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 50,000 100,000 150,000 200,000
HB Core 3
ng/g
1 cm/yr 2.55 cm/yr .75 cm/yr
ATMAC 20-22
52
1935
1940
1945
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 2,000 4,000
HB Core 3
0 50 100 150
HB Core 11
0 2,000 4,000
JB Core 4
0 500 1,000
JB Core 7
Lara-Martin et al. (2010) noted 3 to 4 year doubling times
ng/g
QAC Research and SCP Research Needs
Monitoring data (including California specific) • Aquatic environments, indoor environments,
sensitive subpopulations
Contaminant source information • Particularly product specific source information
• Changes in use, new contaminants, supporting data
Environmental fate of contaminants
Methods and approaches for filling data gaps
Methods and approaches for comparing chemicals with varying amounts of data
53
APPLICATION OF QACS AS SEWAGE TRACERS
1. Source history of individual QACs to the environment
2. PBDE sources in NY/NJ Harbor
3. Source and fate of DEHP in Hempstead Bay
4. Source of trace metals to an Hempstead Bay
54
1. Source history of individual QACs
DTDMAC 18:18 • most hydrophobic, particle reactive, resistant to
degradation, relatively constant time history over last 20 years
• can compare to other QACs that may undergo degradation during burial
• changes in the ratio of an individual QAC to DTDMAC 18:18 can indicate degradation or differences in use histories of other QACs
Li (2009) hypothesized continued increase in the use of small DTDMACs/DADMACs/BACs
55
56
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.1 0.2 0.3 0.4
BAC 18
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.5 1 1.5 2
DTDMAC 16:18
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.05 0.1 0.15
DTDMAC 14:16
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.2 0.4 0.6
DTDMAC 16:16
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.01 0.02 0.03
DADMAC 10:10
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.01 0.02 0.03 0.04
BAC 14
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.01 0.02 0.03 0.04
DTDMAC 12:14
1950
1955
1960
1965
1970
1975
1980
1985
1990
1995
2000
2005
2010
0 0.02 0.04 0.06
DTDMAC 14:14
= JB Core 4 = JB Core 7 = HB Core 3
Benedict, L. A., 2007 PhD
thesis; RPI
Percentage of ∑tri-hexaBDE in PBDEs in sediments from Hudson River Basin
∑tri-hexaBDE% <5%
5%< ∑tri-hexaBDE% <9.8%
∑tri-hexaBDE% >12%
Industrial sources
STP sources
2. PBDEs in NY/NJ Harbor
PBDEs and QACs in NY/NJ Harbor
Li 2009, PhD Thesis
3. Di-ethylhexl phthalate (DEHP)
- Plasticizer
- Suspected endocrine disruptor
- Sewage has been suggested as an important source to aquatic environment but no empirical evidence for this - Other potential sources include landfills, runoff, atmospheric
deposition
- Listed in many of the SCP Product Categories
DEHP in Hempstead Bay
60
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
0 2 4 6 8 10 12 14 16 18 20
DE
HP
ng/g
km from Bay Park Outfall
Probable effects level for DEHP in sediments (MacDonald et al. and 1996)
DEHP and DTDMAC 18:18 in Hempstead Bay
61
0
1000
2000
3000
4000
5000
6000
7000
8000
9000
10000
0 5000 10000 15000 20000 25000 30000 35000 40000
DE
HP
ng
/g
DTDMAC 18:18 ng/g
R2=0.94
DEHP/DTDMAC 18:18 in HB
62
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
0 5 10 15 20
DE
HP
/DT
DM
AC
18
:18
km from Bay Park Outfall
0.000
0.002
0.004
0.006
0.008
0.010
0.012
0.014
0 5000 10000 15000 20000 25000
Zn
/Fe
63
0.00000
0.00001
0.00002
0.00003
0.00004
0.00005
0.00006
0.00007
0 5000 10000 15000 20000 25000
Ag/F
e
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0 5000 10000 15000 20000 25000
Cu
/Fe
0.000
0.001
0.002
0.003
0.004
0.005
0.006
0.007
0 5000 10000 15000 20000 25000
Pb
/Fe
DTDMAC 18:18 (ng/g)
Fe > 2.25%
4. Particle Reactive Metals in Hempstead Bay
QAC Research and SCP Research Needs
Monitoring data (including California specific) • Aquatic environments, indoor environments,
sensitive subpopulations
Contaminant source information • Particularly product specific source information
• Changes in use, new contaminants, supporting data
Environmental fate of contaminants
Methods and approaches for filling data gaps
Methods and approaches for comparing chemicals with varying amounts of data
64
Conclusions
DTDMAC 18:18 potential as a sewage tracer
Illustrate the type of environmental research critical to SCP program • Help assess the chemicals most likely potential for
adverse impacts from environmental exposures
• Help in fulfilling Policy Priorities from Work Plan
65
