UNITED STATES ENVIRONMENTAL PROTECTION AGENCY

WASHINGTON, DC 20460

OFFICE OF PREVENTION, PESTICIDES, AND TOXIC SUBSTANCES

 

						

June 26, 2006

MEMORANDUM

SUBJECT:	Addendum to Residential Occupational and Residential Exposure
Assessment of Pine Oil for the Reregistration Eligibility Decision
Document (RED).

TO:	Mark Hartman, Branch Chief

		Regulatory Management Branch II

		Antimicrobials Division (7510C)

		

FROM:	Cassi Walls, Ph.D., Chemist

	Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510C)

THRU:	Norm Cook, Branch Chief

Risk Assessment and Science Support Branch (RASSB)

Antimicrobials Division (7510C)

Attached is an addendum to the Pine Oil Occupational/Residential
Exposure (ORE) Assessment (September 2004).  This addendum includes a
review of the residential pine oil laundry uses that were inadvertently
excluded from the original memo which was used to support the
Reregistration Eligibility Decision (RED) document.  For a complete
discussion on the toxicity endpoints and all of the other occupational
and residential uses of pine oil, the reader is referred to September
2004 ORE document and risk assessment.

The short- (ST) and intermediate-term (IT) incidental oral MOE as a
result of mouthing treated fabric is 230,000 and is not of concern
(Target ST MOE = 100; Target IT MOE = 1000).  The IT dermal MOEs
calculated for both toddler and adult scenarios are also not of concern
(MOEs = 900,000 and 1,400,000 for toddlers and adults, respectively). 
However, the percent transfer of residues from clothing to skin is
considered a data gap and is necessary to appropriately confirm these
dermal exposures.

Laundry Detergent/Clothing Scenario  SEQ CHAPTER \h \r 1 

Pine oil labels include several laundry uses such as an additive to
laundry detergents, a laundry pre-soak, a diaper pre-soak, and spot
treatment.  Since no short-term dermal endpoint was identified, the
laundry additive, pre-soak, and spot treatment applicator scenarios were
not necessary to assess.  Post-application exposure to the laundry
detergent additive use was selected to represent all post-application
laundry cleaning scenarios (i.e., pre-soak, spot, laundry detergent
additive). To determine post-application dermal (IT) and incidental oral
(ST and IT) exposure to treated clothing via the laundry additive use,
the guidance provided in Human and Environmental Risk Assessment (HERA)
Guidance Document (2003) was used for indirect skin contact from wearing
clothes and oral exposure from mouthing or sucking on treated fabric. 
HERA (2003) provides the following basic equations.

Dermal Exposure

Dermal Exposure (mg/kg/day) = [F1 x (M x F’ x FD)/WI) x Sder x F2 x F3
x F4]/BW

where

	F1	=	weight fraction of ai (EPA Reg 4313-9, 80%)

	M	=	amount of product used (e.g., laundry additive to the detergent),
166 mg (EPA Reg 4313-9)

 	F’	=		percentage of substance deposited on fabric (5%) (HERA 2003)

	FD	=	fabric density for mixed cotton and synthetics (10 mg/cm2) (HERA
2003),

	WI	=		total weight of all fabric being laundered (1E+6 mg) (HERA 2003),

Sder	=	Surface area of the body which is in contact with clothing (5670
cm2 child and 16,900 cm2 adult),

F2	=	weight fraction transferred from clothing to skin (1%) (HERA 2003),

	F3	=	weight fraction remaining on skin (100%) (HERA 2003),

	F4	=		dermal absorption (100%), and

	BW	=	Body weight (70 kg adult; 15 kg child)

Ingestion/Mouthing

Oral Exposure (mg/kg/day) = [F1 x (M x F’ x FD)/WI) x Fm x SE]/BW

where

F1	=	weight fraction of ai (EPA Reg 4313-9, 80%)

M	=	amount of product used (e.g., laundry additive to the detergent),
166 mg (EPA Reg 4313-9)

 	F’	=		percentage of substance deposited on fabric (5%) (HERA 2003)

	FD	=		fabric density for mixed cotton and synthetics (10 mg/cm2) (HERA
2003),

	WI	=		total weight of fabric estimate (1E+6 mg) (HERA 2003),

	Fm	=		fabric area mouthed (100 cm2) (HERA 2003),

	SE	=	saliva extraction efficiency (50%) (HED Residential SOPs), and

	BW	=		Body weight (15 kg)

Data on which these calculations could be based were generally
unavailable; therefore, a number of conservative assumptions have been
made:

Toddlers (3 years old) are used to represent the 1 to 6 year old age
group and are assumed to weigh 15 kg, the median for male and female
toddlers (USEPA, 2000b).  The median surface area for a 3 year old,
minus the head, is 0.567 m2.  Median values for body weights and surface
areas for adults have been used (70 kg and 1.69 m2, not including head
surface area).

No leaching data were available that could be used to estimate a flux
rate of the chemical from clothing.  Therefore, HERA’s assumption of
1% transfer was used.  However, confirmatory data are needed to support
this assumption.

No dissipation data were available, therefore, the amount of pine oil
remaining on the skin is assumed to be 100 percent.

The calculation of the short- and intermediate-term oral and
intermediate-term dermal doses and MOEs are presented in Table 7.  The
ST and IT incidental oral MOE as a result of mouthing treated fabric is
230,000 and is not of concern (Target ST MOE = 100; Target IT MOE =
1000).  The IT dermal MOEs calculated for both toddler and adult
scenarios are also not of concern (MOEs = 900,000 and 1,400,000 for
toddlers and adults, respectively).  However, the percent transfer of
residues from clothing to skin is considered a data gap and is necessary
to appropriately confirm these dermal exposures.

It should be noted that because these MOEs are so large they will have
virtually no impact on the aggregate assessment.  The reader is referred
to the Pine Oil Risk Assessment dated November 1, 2005 for complete
details on the aggregate assessment.

Table 1.  Short- and Intermediate-term Risks Associated with
Postapplication Exposure to Laundered Clothing

Parameter	3-yr old Toddler	Adult	Rationale   

Body Weight	15 kg	70 kg	Median body weight

Surface area, minus head	5,670 cm2	16,900 cm2	Median surface area

Surface area of cloth mouthed	100 cm2	NA	HERA 2003

Concentration on clothing	6.6e-5 mg/cm2	(166 mg product x 80% ai x 5%
clothing deposition x 10 mg/cm2 cloth density)/1E+6 mg weight of fabric.
 EPA Reg. No. 4313-9.

Daily Dermal Dose	2.5e-4 mg/kg/day	1.6e-4 mg/kg/day	(concentration on
clothing mg/cm2 x surface area cm2 x transfer efficiency 1% to skin) x
(100% dermal absorption) / Body Weight

Incidental Oral Ingestion (mouthing)	2.2e-4

mg/kg/day	NA	(concentration on clothing mg/cm2 x surface area mouthed
cm2 x saliva extraction 50%) / Body Weight

Intermediate Dermal NOAEL	226 mg/kg/day	Dermal endpoint selected

Short- and Intermediate Oral NOAEL	50 mg/kg/day	Oral endpoint selected

Intermediate Dermal MOE	1,400,000	900,000	(NOAEL) / (Dose).  

Target MOE = 100

Incidental Oral MOE (mouthing)	230,000	NA	(NOAEL) / (Dose). 

Short-term Target MOE = 100

Inter-term Target MOE = 1000



  166 mg product = (6 oz product) x (1cup/8oz) x (236.59 ml/cup) x
(gal/3790ml) x (7.94 lb/gal) x (kg/2.24lb) x (1000mg/kg)

where 7.94 lb/gal is the density of 100% pine oil 

where specific gravity of pine oil = 0.952 and density of water = 8.34
lb/gal  therefore 8.34 lb/gal x 0.952 = 7.94 lb/gal

