Document ID: EPA-HQ-OPP-2007-0513-0007
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2008-05-07T04:00Z

MEMORANDUM							April 5, 2007

Subject: 		Dietary Risk Assessment for Triclosan for the RED Process

From:			A. Najm Shamim, PhD., Chemist

			Regulatory Management Branch II

			Antimicrobials division (7510P)

To:	Tim McMahon, PhD., Senior Toxicologist	

Antimicrobials Division (7510P)

Thru:	Diane Isbell, Triclosan CRM / Team Leader

	Regulatory Management Branch II

	Antimicrobials Division (7510P)

			And

	Mark Hartman, Chief

	Regulatory Management Branch II

	Antimicrobials Division (7510P)

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EXECUTIVE SUMMARY

As pursuant to the Agency policy AD has carried out the dietary risk
assessment form the AD use patterns which present the indirect food
contact scenarios. AD has conducted the risk assessment of those use
patterns which triggered the possibility of indirect food migration from
paper/pulp use ,  ice-making equipmentd, adhesives cutting boards, and
counter tops uses as well use in conveyer belts. All  % aPADs and  %
cPADs  for adults and children for Triclosan uses fall well below
Agency’s level of  concern.

DIETARY RISK ASSESSMENT FROM INDIRECT FOOD USES OF TRICLOSAN

Background: 

AD’s label search has shown that Triclosan is used in may scenarios
which trigger risk assessment for the  indirect food contact purposes.
The following table lists the use patterns, and application rates of 
Triclosan.

					Table I

Product Name/EPA Reg#	Use Scenario	Application Rates

DPN-10/Sanitized Brand T96-2/ 3090-165	Paper	10% Formulation; no other
information is provided

Ultra Fresh NM/10466-27	Adhesives	3% Formulation; no other information
is provided

Ultra Fresh FT-7/10466-42	Emulsions/adhesives	1.5%

Microban  Additive B 	Counter tops, cutting boards, conveyer belts,
ice-making equipments, paper/paperboard	0.1%  to 1.0% of the 99% TGAI

Igraguard B1000/70474-5	Conveyer Belt, cutting board	Conveyer belt: 2%
Formulations

Cutting Boards: 1% formulations

	RESIDUE CHEMISTRY

	All uses of Triclosan are nonagricultural, and no residue chemistry
data based on Agency’s Residue Chemistry Guidelines (OPPTS GLN
860.xxx) were submitted nor the Agency asked for it.  Therefore, The
Agency has used available methods to estimate Triclosan residues on food
due to migration of this chemical, when this chemical comes in to
contact with food-contact paper. In this regard Food and Drug
Administration has developed guidelines to estimate residues in food due
to migration into food.

Antimicrobials Division in the recent REDs has included the scenarios
like: paper/pulp, paperboard, adhesives, counter tops, cutting boards,
conveyer belts, and ice-making equipments as a source of indirect food
contacts surfaces and a cause of migration of pesticides into foods. 
For all  senarios AD has heavily used FDA methodology for calculating
the estimated daily intakes (EDI),  and daily dietary doses (DDD). In
turn, we calculate the % a-and cPADs for the US populations to determine
if there any exceedences. For conveyer belt scenario, we have adapted
the FDA methodology to calculate the EDI, DDDs to estimate the %  a-and
cPADs

Detailed Discussion:

1) 	Paper and Paperboard Use:

	FDA1,2, Method makes a number of assumptions for calculating migration
of active (in this case Triclosan) from food contact surfaces (paper):
1. Food contact surface (paper) can be a one time use/day or a repeat
use material; 2. Consumption factor (CF) or fraction of daily food which
comes in to contact with the packaging surface (paper). CF represents
the actual weight of food that comes into contact with the paper to the
weight of all food packaged with paper; 3. The CF varies from one type
of packaging (type of paper) to the other (type of paper). FDA
methodology of migration of active assumes a 100% migration to the food
commodities(This represents a worst case scenario).

Note:	No information is provided  for application rate on paper use of
Triclosan as a fungicide; but the percent of the active (Triclosan) in
the formulation  10%. In the absence of actual data, we will use the
highest application rate which is 10% of formulations. It is therefore
assumed that  the  amount (lb) of Triclosan in the formulation is: 10
lbs x 10% = 1 lbs active per 1000 lbs paper For 2000 lbs of the product,
the amount of the active = 2 lbs. For our calculations  we assume  2000
lbs paper ~ 1 ton paper. 

2 lb active /2000 lb of finished paper = 908 ppm active  mg/kg of 
finished paper

 But the paper slurry is 1% ; 908 mg x 01 = 9.08  active mg/kg of
finished paper = ~ 10 ppm of active in the paper slurry= Application
Rate

Application  rate x % water / % pulp = 10 ppm  = 5µg/g pulp slurry x
0.67g water/0.33.g pulp = 20 µ g of active/g pulp.

Consumption Factor (CF) = 0.10

	Likely amount of Triclosan  migrating into food:

20 µg of Triclosan ⁄ mass of pulp x 0.92 g pulp∕ g of paper x 0.05
g ∕ in2 x 1 in2 ∕ 10 g food = 0.092µ g of Triclosan ∕ g food

Since the Consumption factor for paper, based on FDA’s methodology is
0.10

The  actual amount of Triclosan in daily diet will be:

0.092µg of Triclosan g food x 0.10 = 0.0092 µg ∕ g food

Estimated Daily Intake (EDI) of Triclosan for an adult:

0.0092µg of Triclosan∕ g food x 3000 g food =27.6µg of
Triclosan/person/day

Estimated Daily Intake (EDI) of Triclosan for a child:

0.0092µg of Triclosan ∕ g food x 1500 g food = 13.8 µg of
Triclosan/person/ day

 (A Memo by Tim McMahon  to Jess Rowland, Executive Secretary for
Agency’s HIARC Committee, 1998)  indicated that AD scientists
determined both the Acute dietary and chronic dietary end points and
based on the selection, the aRfD  (aPAD)and cRfD (aPAD)  have the same
value i.e.,:  0.30 mg/kg/day

In Table  II estimations are given for % aPAD and % cPAD.

				Table II

		Dietary Exposure of Triclosan from Paper/Pulp/ Paperboard

		

Dietary Conc. of  Triclosan	Estimated Daily Intake (EDI)	Daily Dietary
Dose (DDD): mg/kg/day	% aPAD

(aPAD = 0.30 mg/kg/day)	% cPAD (cPAD = 0.30 mg/kg/day)

20.0 µ g	Adult: 27.6 µg

	Adult: 27.6 µg/70 kg/day = 0.00039 mg/kg/day

	Adult: 0.00039 mg/kg/day ∕ 0.30 mg/kg/day x 100

= 0.13%	Adult: 0.00039 mg/kg/day/0.30 mg/kg/day x 100 = 0.13%

	Child: 13.8  µg 	Child: 13.8µg/ 15 kg/day = 0.00092 mg/kg/day	Child:
0.00092 mg/kg/day ∕ 0.37 mg/kg/day = 0.30% 	Child: 0.00092 mg/kg/day /
0.037 mg/kg/day = 0.30%

The calculations of % aPAD and cPAD  show that there are no acute  and
chronic dietary concerns from the migration of Triclosan from paper to
food. 

Adhesive Use of Triclosan

As a matter of policy, AD has assessed adhesive use as an indirect food
use.  Since it is likely that adhesives may end up in the food packaging
materials, and this may result in the migration of the pesticide into
the food indirectly.  For the indirect food dietary assessment, AD has
adopted Food & Drug Administration (FDA) methodology.  For adhesive use,
FDA has provided guidance for dietary estimation that a maximum of 7 ppb
of a pesticide is likely to migrate from the food packaging materials
into the food. The quantity of 7 ppb can be used to calculate the
Estimated Daily Intake (EDI), Daily Dietary Dose (DDD), and using the
acute and dietary end points from toxicity data, one calculates the
overall risks to general and subgroups of populations ( % aPAD, and %
cPAD).

For the present case: FDA’s assumptions are: 1) Maximum migration of 
Triclosan  into food from adhesive use = 7 ppb = 7µg/g; 2) Maximum
adult food intake = 3000 g; 3) Maximum food intake for a child = 1500 g.

In general, % PAD =  DDD/% a PAD or % cPAD.

Table III gives estimates of % cPAD for adhesive use of Triclosan

Table III					

			Dietary Exposure of Triclosan from Adhesive Use

Use	Dietary Conc. (ppb)	Estimated Daily Intake (EDI) µg/p/day	Daily
Dietary Dose (DDD) mg/kg/day

 

	% aPAD

(aPAD= 0.30 mg/kg/d)	% cPAD

( cPAD = 0.30 mg/kg/d)

Adhesive	7	Adult: 7µg/g x 3000g = 21 µg/p/day

Child: 7 µg/g x 1500 g = 10.5 µg/p/day	Adult: 21 µg/70 kg/day =
0.0003 mg/kg/day

Child: 10.5 µg/15kg/day = 0.0007 mg/kg/day	Adult: 0.0003/0.30 x 100) =
0.10%

Child: 0.0007/0.30 x100 = 0.23%	Adult:  0.0003 mg/kg/day ∕ 0.3
mg/kg/day x100 = 0.10%

Child: 0.0007 mg/kg/day ∕ 0.30 mg/kg/day x 100  = 0.23 %

	

These calculations assume that the adhesive use is 100% of the chemical
produced, which is not a likely scenario. The actual  % cPAD is going to
be much lower than the estimated one The Agency has no chronic dietary
concerns from the use of Triclosan in adhesives.

Ice-making Equipment

AD makes the following assumptions to calculate the exposure of
Tricolsan use  from ice-making equipments:

Use of Ice/water/day = 50%  ice/water mixture

Male adult uses 2000L/day and child uses 1000L/day of ice-water mixture

Table IV summarizes the daily dietary dose and % aPAD and % cPAD for
ice-making equipment:

	

				Table IV

	Exposure from Triclosan Use  from Ice-Making Equipment

Daily Dietary Dose (DDD) mg/kg/day1	% aPAD ( aPAD = 0.30 mg/kg/day)	%
cPAD (cPAD = 0.30 mg/kg/day)

Male Adult: 1.13 x10-8  mg/kg/day

Child: 2.65 x 10-8  mg/kg/day	Male Adult: 1.13 x10-8  mg/kg/day/ 0.30
mg/kg/day = 3.76 x 10-8  x 100 = 3.76 x 10-6  %

Child: 2.65 x 10-8  mg/kg/day /0.30 mg/kg/day = 8.83 x 10-8  x 100 = 
8.83  x 10-6  %	Male Adult: 1.13 x10-8  mg/kg/day/ 0.30 mg/kg/day = 3.76
x 10-8  x 100 = 3.76 x 10-6  %

Child: 2.65 x 10-8  mg/kg/day /0.30 mg/kg/day = 8.83 x 10-8  x 100 = 
8.83  x 10-6  %

	Note: 1) Calculations reported by Bob Quick in  a  Memo by Bob Quick to
Bob Brennis, 1998.

4) 	Counter Tops and Cutting Boards:

Table V lists the input parameters and explanations for EDI, DDD, % aPAD
and % cPAD for Triclosan use on counter tops, and cutting board.

					Table V

Parameter	Comment	Value/Units

AR	Application Rate, usually highest application rate is used	ppm or 
µg

RS	Residual solution	1 mg/cm2 , adapted from FDA methodology

SA	Treated surface area which comes into contact with food	Cm2 ; assumed
to be 2000 cm2 for counter tops and cutting boards

F	% fraction of the active	No units; normally Agency has sued 10%.

BW	Body Weight	Adult: 70 kg; child: 15 kg

EDI	Estimated Daily Intake	= AR * RS * SA * F

DDD	Daily Dietary Dose	= EDI/BW

aPAD	Acute dietary end points	For Triclosan: 0.30 mg/kg/day

cPAD	Chronic Dietary end point	For Triclosan: 0.30 mg/kg/day

% aPAD	Ratio of DDD and aPAD	% population affected (acute)

% cPAD	Ratio of DDD and cPAD	% population affected

Table VI provides the summary of calculations and results for EDI, DDD,
% aPAD, and % cPAD; based on: a) maximum application rate = 1%; aPAD =
0.30 mg/kg/day and cPAD = 0.30 mg/kg/day; fraction % = 10%; and maximum 
surface area food is exposed to the pesticide = 2000 cm2

					Table VI

Parameter	Calculations/Results

EDI	AR * RS* SA * F; =  10,000 µg/1000 mg (ppm) * 1 mg/cm2 * 10/100 *
2000 cm2 = 2000 µg

DDD	Adult: EDI/70 kg/day = 2000µg/70 = 28.6 µg/kg/day; Child: EDI/15
kg/day = 2000µg/15 kg/day = 133. 3 µg/kg/day

% aPAD	DDD/ aPAD x 100 ; Adult: 0.0286 mg/kg/day/ 0.30 mg/kg/day = 9.53%

Child: 0.1333 mg/kg/day/ 0.3 mg/kg/day x 100 = 44.3%

% cPAD	 Adult = 9.53%; Child = 44.3%

All results  are below level of concern. These results are very
conservative and the likelihood of exposure from counter tops and
cutting board use on a regular basis of 7/24/year is minimum.  In
addition use of surface area of 2000 cm2  of 7/24/year is also not
likely. The Agency believes the actual exposure form counter tops and
cutting boards will be much lower than the results shown here

Conveyer Belt Use.

Triclosan is used as a material preservative in a number of  commodities
made up of synthetic fibers  as thin films like polyesters, latex,
polypropylene, polyethylene etc. 

Conveyer belts are generally made from polyethylene materials and
Triclosan is used as a material preservative.  In food establishments,
grocery stores, food storage establishments, conveyer belts are used to
move foods along. There is a likelihood that some of the Triclosan
migrates form the belts to the food which is being moved on the belt.
FDA has established some in put parameters for such a scenario.  In
addition, AD industry provded us with a few parameters which are used as
a common industry practice. Although  label Triclosan (EPA REG#:
70404-5) has provided the maximum rate of application of 2% formulation,
it is not clear how this is spread out on the conveyer belt and in this
regard Agency has made its own assumptions.

Table VII lists the FDA and industry parameters, and Agency’s
assumptions for calculating the EDIs for Triclosan when it is migrated
into food through indirect contact with the conveyer belt surfaces.

					Table VII

In Put Parameters /Assumptions	Explanations/ Units

Average length of  conveyer belt 13 meters	Industry practice

Average Width of conveyer belt: 1 m	Industry practice

Surface area of  conveyer belt (A)	13 m x m = 13 m2 = 20386 in2

Volume/surface ratio for food simulating liquid= 6.7 mL/in2 (B)	FDA
assumption

Amount of food placed on 1150 in2 = 8 x 103 kg   or 8 x 106 g/1150 in2  
(C)	FDA assumption

Polyethylene used to make conveyer belt	EPA assumption

Maximum migration of Triclosan into food simulating liquid (50%
ethanol/water) = 0.9 ppm (D)	FDA assumption

Rate of Application on the conveyer belt = 2% solution (E)	Industry data

2% solution = 2g/100 g ; 20 g/kg solution spread over/meter of conveyer
belt  (F)	EPA assumption

Use of conveyer belt /year (G)	260 days/Industry practice

Time period of maximum migration (H)	First  5 days: industry data

Amount of food which passes through the conveyer belt: A * C 

X = A * C = 20386 in2  * 8 x 106 = 1.42 x 108  g 

Maximum Migration of Triclosan from the conveyer belt: B * D = Y

Y =  0.90ppm = 900 ng/ml x 6.7 ml/ in2 = 6.03 µg/in2 

Total migration of Triclosan into all food: A * Y /X = Z

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 = 0.000866 mg/day = Estimated daily intake (EDI)

Table VIII summarized the DDD,  % aPAD and % cPAD 

				TableVIII

Parameter	Calculations/Results

DDD	Adult: 0.000866 mg/70kg/day = 0.0000123 mg/kg/day

Child: 0.000866 mg/15kg/day = 0.000057 mg/kg/day

% aPAD and % cPAD	Adult: 0.0000123 mg/kg/day/0.30 mg/kg/day x 100 =
0.041%

Child:  0.000057 mg/kg/day / 0.30 mg/kg/day x 100 = 0.019%

Conclusions:

	None of the indirect food contact scenarios appear to exceed 
Agency’s level of concern.

				BIBLIOGRAPHY

FDA, 2003, A Guidance For Industry: Preparations of food Contact
Notifications and Food Additive Petitions for Food Contact Substances,
Chemistry Recommendations. Final Guidance, April 2003.   HYPERLINK
"http://www.cfsan.fda.gov"  http://www.cfsan.fda.gov 

FDA, 2003.  Sanitizing  Solutions: Chemistry Guidance for Food Additive
Petitions, January 2003.   HYPERLINK "Http://www.cfsan.fda.gov" 
Http://www.cfsan.fda.gov 

An AD Memo by Tim McMahon  to Jess Rowland, Executive Secretary for
Agency’s HIARC Committee, 1998)

4.	Calculations reported by Bob Quick in  an AD   Memo by Bob Quick to
Bob Brennis, 1998.