**[MEMORANDUM]{.underline}**

**Date:** 3/23/2006

**SUBJECT:** Dietary Risk Assessment for Alkylbenzene Sulfonates

**REVIEWER:** Robert Quick, Chemist

Risk Assessment & Science Support Branch

Antimicrobials Division (7510C)

**THROUGH:** Norm Cook, Chief

Risk Assessment & Science Support Branch

Antimicrobials Division (7510C)

**TO:** Heather Garvie, Chemical Review Manager

Regulatory Management Branch

Antimicrobials Division (7510C)

**PC CODES:** 079010 Sodium dodecylbenzene sulfonic acid

098002 Dodecylbenzene sulfonic acid

190116 C10-16-Alkylbenzene sulfonic acid

**DP BARCODES:** D327731

**DECISION #:** 362580

**Alkylbenzene Sulfonate Dietary Exposure**

**The Registration Elgibility Document (RED) covers the potential
dietary exposure to the active ingredient(s) sodium dodecylbenzene
sulfonate, dodecylbenzene sulfonate and benzene sulfonic acid.** **This
RED does not address the dietary exposure that will result from the use
of products containing these chemicals as inert ingredients.** Chemicals
classed as any of these chemicals are being considered together because
chemicals named dodecylbenzene sulfonate actually contain alkylbenzene
sulfonates in addition to dodecylbenzene sulfonate. Labeling
modifications will be made to these chemicals as a result of the
reregistration process.

The uses for these chemicals include: (1), food handling/storage
establishments, premises and equipment; (2) agricultural premises and
equipment; and (3) fruit and vegetable rinses.

The 21 CFR 178.1010 Regulation for sanitizing solutions read:

Dodecylbenzene sulfonate:178.1010(b)(7) and 178.1010(c)(5).

The site reads: "In addition to use on food-processing equipment and
utensils, this solution may be used on glass bottles and other glass
containers intended for holding milk". The use limitation for the
chemical is 400 ppm.

Dodecylbenzene sulfonic acid: 178.1010 (b)(10) and 178.1010 (c)(7).

The site reads: "In addition to use on food-processing equipment and
utensils, this solution may be used on beverage containers except milk
containers or equipment". The use limitation is 400 ppm.

Sodium dodecylbenzenesulfonate: 178.1010(b)(21) and 178.1010(c)(16).

The site reads, "In addition to use on food processing equipment and
utensils this solution can be used on glass bottles and other glass
containers intended for holding milk". The use limitation is 430 ppm
equivalent to \~ 400ppm of the free acid.

Dodecylbenzene sulfonic acid; 178.1010(b)(40) and 178.1010(c)(35).

The site reads: "In addition to use on food-processing equipment and
utensils, this solution may be used on dairy processing equipment". The
use limitation is 5.5 ppm.

It appears that dodecylbenzenesulfonic acid solutions containing up to
400 ppm can be used on glass bottles and containers containing milk but
cannot be used on dairy processing equipment at this level. The
registrant and user may have difficulty in distinguishing between
glass-lined equipment and glass containers.

These 21 CFR citations do not specifically state that the solutions may
be used on food contact articles including dishes, pots and pans,
glasses etc. However, there are many labels registered for use on these
sites.

The 40 CFR 180 Regulation reads:

+-----------+-------+------+----+----------------------------+-------+
| **        | **CAS | **PC | ** | **Use Pattern              | **A   |
| Tolerance | No.** | Co   | 40 | (Pesticidal)**             | ctive |
| Exemption |       | de** | C  |                            | Produ |
| Expr      |       |      | FR |                            | cts** |
| ession/** |       |      | 18 |                            |       |
|           |       |      | 0. |                            |       |
| *         |       |      | ** |                            |       |
| *Chemical |       |      |    |                            |       |
| Name**    |       |      |    |                            |       |
+===========+=======+======+====+============================+=======+
| Benzen    | 27176 | 09   | 9  | food contact sanitizing    | 18    |
| esulfonic | -87-0 | 8002 | 40 | solutions for dairy        |       |
| acid,     |       |      | (  | processing equipment, and  |       |
| dodecyl-  |       |      | b) | food processing equipment  |       |
|           |       |      |    | and utensils; end use      |       |
|           |       |      |    | concentration not to       |       |
|           |       |      |    | exceed 5.5 ppm             |       |
+-----------+-------+------+----+----------------------------+-------+
|           |       |      | 9  | food contact sanitizing    |       |
|           |       |      | 40 | solutions for food         |       |
|           |       |      | (  | processing equipment and   |       |
|           |       |      | c) | utensils; end use          |       |
|           |       |      |    | concentration not to       |       |
|           |       |      |    | exceed 400 ppm             |       |
+-----------+-------+------+----+----------------------------+-------+
| Benzen    | 25155 | 07   | 9  | food contact sanitizing    | 3     |
| esulfonic | -30-0 | 9010 | 40 | solutions for food         |       |
| acid      |       |      | (  | processing equipment and   |       |
| dodecyl-, |       |      | c) | utensils; end use          |       |
| sodium    |       |      |    | concentration not to       |       |
| salt      |       |      |    | exceed 430 ppm             |       |
+-----------+-------+------+----+----------------------------+-------+

**The RMB II Chemical Review Manager should ascertain the correct use
sites and limitations for these chemicals.**

Many of the labels include uses for the sanitization of food serving
equipment, glasses, dishes, utensils and pots and pans. These surfaces
that have been treated with the dodecylbenzene sulfonate products may
bear small residues of the dodecylbenzene sulfonate Residues from
treated surfaces can migrate to food coming into contact with the
treated surfaces and can be ingested by humans.

The maximum label rates for the dodecylbenzene sulfonates are 400 ppm
for use in antimicrobial formulations (Food contact surface sanitizing
solutions).

**[The maximum rate for dodecylbenzene sulfonates in sanitizer end-use
solutions is 400 ppm except for dairy processing equipment. Uses on food
processing equipment are discussed below under "Food Processing
Industry".]{.underline}**

**FOOD CONTACT SURFACES IN THE FOOD SERVICE INDUSTRY**

**[AD will use the 400 ppm level permitted in an end use solution in our
calculations.]{.underline}**

In the absence of residue data for residues of dodecylbenzene sulfonate
on treated food contact surfaces reflecting the registered use patterns,
the Agency can calculate residue levels that may occur in food from the
application rates on food contact surfaces.

To estimate the Estimated Daily Intake (EDI), the Agency has used the
following model calculation. This model is taken from FDA Guidelines.

> **The maximum ingredient percentage for dodecylbenzene sulfonates
> registered for use in food handling establishments in kitchens,
> cafeterias, supermarkets and meat and poultry plants is 400 ppm).**

**EDI** = (1 mg/cm^2^) x wt. fraction of wash solution (AR) x SA x FMF/
BW

Where:

AR = Application rate

SA = surface to which food is exposed, assume 4000 cm^2^

FMF = Fraction of pesticide migrating to food, assume 100%\*

BW = 70 for male adults, 60 kg for female adults and 15 kg for children

**EDI from the FDA model** = 400 µg/1000 mg (ppm) x 1.0 mg/cm^2^ x 4000
cm^2^ /person/day

= 1600 µg dodecylbenzene sulfonate/person/day

Assuming that an average adult consumes 3000 gm of food per day,

**Then 1600 µg a.i./3000 gm food = 0. 53 µg a.i./gm (ppm) of food**

**This calculation reduces the dietary consumption to µg of a.i. per gm
of food.**

**Assume that an adult consumes 3000 gm of food /day**

> **1600 µg a.i./70 kg BW = 22.9 µg dodecylbenzene sulfonate/kg/day for
> a male adult**
>
> **1600 µg a.i./60 kg BW = 26.7 µg dodecylbenzene sulfonate/kg/day for
> a female adult**

Assuming that a child consumes 1500 gm of food per day,

**Then: 0. 53 µg a.i./gm (ppm) of food x 1500 = 795 µg a.i./day**

**800 µg a.i./15 kg BW = 53 µg dodecylbenzene sulfonate/kg/day for
child**

**FOOD CONTACT SURFACES IN THE FOOD PROCESSING INDUSTRY**

The 21 CFR 178.1010 Regulations and the 40 CFR 940 Regulations do not
specifically permit the use on milk processing equipment at a level of
400 ppm.

However, the labels include uses for the sanitization of food processing
equipment such as tanks, pipelines, evaporators, filters, pasteurizers,
aseptic equipment including dairies, wineries, breweries and beverage
plants, meat and poultry processing/packing plants, milk and dairy
products /packing plants, seafood and vegetable processing/packing
plants, food processing/packing plants and egg processing/packing
equipment surfaces. These uses would permit the sanitization of the
interior of food processing and storage equipment.

**This use could be additive to the treatment of food contact surfaces
such as glasses, dishes, utensils and pots and pans.**

AD will use an FDA model to estimate residues that could transfer from
treated surfaces to food from this type of use.

According to the FDA, the exposure estimates for this type of use can be
calculated using the milk truck model that is described in the FDA
document, "Sanitizing Solutions: Chemistry Guidelines For Food Additive
Petitions", pages 9-10.

This guidance states on page 9, "For applications limited to use of the
food sanitizer on food processing equipment and utensils, the Agency has
determined that estimates of sanitary exposure from use in dairy
processing plants significantly exceed estimates based on other uses
with food processing equipment and utensils. Depending on the available
safety data, the petitioner may either submit a petition for the broader
use of its sanitizer on "food processing equipment and utensils
including dairy processing plants" or for the more limited use on "food
processing equipment and utensils excepting use in dairy processing
plants."

The next paragraph of the document states, "The following simplified
example will illustrate the calculation of the EDI of residual sanitizer
solution in milk from sanitizer use in a dairy processing plant.
Although in practice consideration of all of the components of a milk
handling system must be included as sources of sanitizer residue in
milk, for this example the only source is assumed to be a sanitized tank
truck to transport the milk. It is further assumed that the milk
undergoes no additional dilution prior to reaching the consumer.
Assuming a cylindrical model for the tank truck (4000 gallon capacity)
with a length of 19.9 feet and cross-sectional diameter of 6 feet, and
an internal surface area of 413 sq ft is calculated for the tank.
Assuming that the sanitizer treatment leaves a residue of 1 mg/sq cm and
the 'at use' concentration of component X is 200 ppm, the concentration
of X in the milk residing in the tank would equal:

413 sq ft/1 truck x 1truck/4000gal x 1 mg/sq cm x 200 µg/1000 mg x 929
sq cm/1 sq ft x 0.264 gal/1L = 5.1 µg x/L milk \~ 5.1 ppb".

The maximum application rate for the dodecylbenzene sulfonate chemicals
in food processing equipment is 400 ppm.

Then using the FDA model, residues resulting in milk from the use would
be calculated as:

413 sq ft/1 truck x 1truck/4000gal x 1 mg/sq cm x 400 µg/1000 mg x 929
sq cm/1 sq ft x 0.264 gal/1L = 5.1 µg x/L milk \~ 10.1 ppb.

If an adult were to consume 3000 gm of food per day containing 10.1µg/L
or 10.1µg/kg (1000 gm), then the person would ingest 30.4 µg of
dodecylbenzene sulfonate per day.

A child consuming 1500 gm of food per day would consume would ingest
15.2 µg of dodecylbenzene sulfonate per day.

**DIETARY EXPOSURE ASSESSMENT FOR THE FOOD SERVICE AND FOOD**

> **PROCESSING INDUSTRIES**

**TABLE 1**

Cumulative Estimated Dietary Intake of LAS

+----------------+---------------+------------------+-----------------+
| **Use**        | **Dietary     | **Estimated      | **Daily Dietary |
|                | Conc.**       | Daily Intake**   | Dose**          |
|                |               |                  |                 |
|                | **(ppb)**     | **(              | **(mg/kg        |
|                |               | μg/person/day)** | bw/day)**       |
+----------------+---------------+------------------+-----------------+
| Food Service   | 0.53 ppb      | 1600 (adult M)   | 0.023 (adult M) |
| Industry       |               |                  |                 |
|                |               | 1600 (adult F)   | 0.027 (adult F) |
|                |               |                  |                 |
|                |               | 800 (child)      | 0.053 (child)   |
+----------------+---------------+------------------+-----------------+
| Food           | 10.1 ppb      | 30.3 (adult M)   | 0.00043 (adult  |
| Processing     |               |                  | M)              |
| Industry       |               | 30.3 (adult F)   |                 |
|                |               |                  | 0.00050 (adult  |
|                |               | 15.1 (child)     | F)              |
|                |               |                  |                 |
|                |               |                  | 0.001 (child)   |
+----------------+---------------+------------------+-----------------+
| Cumulative     | 12.6 ppb      | 1630.3 (adult M) | 0.023 (adult M) |
|                |               |                  |                 |
|                |               | 1630.3 (adult F) | 0.027 (adult F) |
|                |               |                  |                 |
|                |               | 815.1 (child)    | 0.054(child)    |
+----------------+---------------+------------------+-----------------+

There were no effects attributable to a single dose for the acute
dietary risk (Deborah Smegal memo.

Utilizing the chronic RfD or cPAD of 0.5 mg/kg/day taken from the
Deborah Smegal memo, the dietary risks were estimated in Table 2 below.

\% PAD = exposure/PAD x 100

> **TABLE 2**

Dietary Risks of LAS

+-------------+--------------------+--------------------+-------------+
| **USE**     | **DAILY DIETARY**  | **% aPAD**         | **% cPAD**  |
|             |                    |                    |             |
|             | **DOSE**           |                    |             |
|             |                    |                    |             |
|             | **(mg/kg bw/day)** |                    |             |
+-------------+--------------------+--------------------+-------------+
| Food        | 0.023 (adult M)    | No effects         | 4.6%        |
| Service     |                    |                    |             |
|             | 0.027 (adult F)    | No effects         | 5.4%        |
| Industry    |                    |                    |             |
|             | 0.053 (child)      | No effects         | 10.6%       |
+-------------+--------------------+--------------------+-------------+
| Food        | 0.00043(adult M)   | No effects         | 0.086%      |
| Processing  |                    |                    |             |
| Industry    | 0.00050 (adult F)  | No effects         | 0.1%        |
|             |                    |                    |             |
|             | 0.001 (child)      | No effects         | 0.2%        |
+-------------+--------------------+--------------------+-------------+
| Cumulative  | 0.0234(adult M)    | No effects         | 4.69%       |
|             |                    |                    |             |
|             | 0.0275(adult F)    | No effects         | 5.5%        |
|             |                    |                    |             |
|             | 0.054(child)       | No effects         | 10.8%       |
+-------------+--------------------+--------------------+-------------+

The food service and food processing industry uses do not result in
dietary risks of concern.

**[FRUIT AND VEGETABLE WASH]{.underline}**

The label, CS-100 Acid Anionic Sanitizer, EPA Reg. \# 71695-1, bears a
use for washing fruits and vegetables.

The FDA Regulation, 21 CFR 173.315, permits this use provided that the
wash solution does not contain dodecylbenzene sulfonic acid at a level
greater than 0.2%. No potable water rinse is required by the Regulation.
We presume that the use limitation is for the parent chemical because
the Regulation makes no mention of formulations. The use limitation
states, "Not to exceed 0.2%in wash water. May be used in washing or to
assist in the lye peeling of fruits and vegetables". Note: If the use
limitation were intended to apply to a formulation, there would be a
broad range of application rates depending on the concentration of the
chemical in the formulation.

The label bears a use that provides for a fruit and vegetable wash with
a solution containing 0.16 % dodecylbenzene sulfonic acid, without a
potable water rinse.

The label also bears a use a use that provides for a fruit and vegetable
wash with a solution containing 0.31% dodecylbenzene sulfonic acid,
[with a potable water rinse]{.underline}.

There are no data to show that the level of residues on fruits and
vegetables would be reduced to the level that would have occurred from a
0.2% wash. However, AD concludes that dodecylbenzene sulfonic acid
residues would be significantly reduced by the potable water rinse and
would be less than residues resulting from the 0.2% wash.

There are no residue data to show the level of dodecylbenzene sulfonic
acid that will result on fruits and vegetables from the 0.2% wash
solution with a potable water rinse. Lacking residue data to show the
level of residues expected on fruits and vegetables, we have calculated
the level of residues on fruits and vegetables using the following
model.

**Dodecylbenzene sulfonate Fruit and Vegetable Wash Dietary Residue
Calculations**:

[Calculation for percent dodecylbenzene sulfonate in the wash
water]{.underline}:

The maximum use rate is 2000 ppm of dodecylbenzene sulfonate (0.2% x
10,000) for fruit and vegetables.

We will use the surface area and weight of Thompson Seedless grapes to
calculate residues in fruits and vegetables. This is a small grape which
accounts for half of the table grapes grown in California and is used to
make over 90% of the grapes grown in the United States.

[Grapes specifications]{.underline}:

Diameter of one grape = 16 mm

(Source: University of California Cooperative Extension, Tulare County

[http://cetulare.ucdavis.edu/pubgrape/tb195.htm](http://www.ces.uga.edu/ES-pubs/RR662.htm#CPPU Enhances Fruit Set)

Mass of one grape = 4.0 gm or 0.0040 kg

(Source: University of California Cooperative Extension, Tulare County

[http://cetulare.ucdavis.edu/pubgrape/tb195.htm](http://www.ces.uga.edu/ES-pubs/RR662.htm#CPPU Enhances Fruit Set)
)

Surface area of one grape = 15.88 cm^2^

Based on surface area of a sphere where A = 4πr^2^ (where r = 8 mm)

A = 4 x 3.14 x (8 mm)^2^

A = 803.8 mm^2^

A = 8.04 cm^2^

[Amount of Residue on Grapes:]{.underline}

Assume the film thickness of the solution on the surface of the grape is
0.0023 g/cm^2^

(Source: Proctor and Gamble exposure assessment for ingestion of
dishwashing product residues - based on the amt of rinse water in
contact with dishware surfaces
http://www.scienceinthebox.com/en_UK/safety/ingestionfromsurface_en.html)

0.0023 g/cm^2^ x 8.04 cm^2^ x 0.002 (0.2%) dodecylbenzene sulfonate =
0.0000369 gm or 0.037 mg dodecylbenzenesulfonate

0.037 mg dodecylbenzene sulfonate/0.004 kg grape = 9.25 mg/kg or ppm

> **DIETARY EXPOSURE ASSESSMENT FOR THE FRUIT AND**
>
> **VEGETABLE WASH**

This part of the non-cancer dietary risk assessment was carried out by
Cassi Walls (RASSB/AD). It was conducted using the Dietary Exposure
Evaluation Model (DEEM-FDIC^™^), Version 2.03 which uses food
consumption data from the USDA's Continuing Surveys of Food Intake by
Individuals (CSFII) from 1994-1996 and 1998. This assessment is Tier 1,
conservative (assumes 100% crop treatment) and uses the deterministic
approach. As input parameters for modeling analyses, the level of 9.25
ppm was used based on the modeling discussed above.

**TABLE 3**

> Dietary Risk for Fruit and Vegetable Wash

+-----------------+-----------------+-----------------+-----------------+
| **USE**         | **DAILY         | **% aPAD**      | **% cPAD**      |
|                 | DIETARY**       |                 |                 |
|                 |                 |                 |                 |
|                 | **DOSE**        |                 |                 |
|                 |                 |                 |                 |
|                 | **(mg/kg        |                 |                 |
|                 | bw/day)**       |                 |                 |
+-----------------+-----------------+-----------------+-----------------+
| Fruit and       | 0.0979 (U.S.    | No Effects      | 19.6%           |
| Vegetable       | Pop.)           |                 |                 |
|                 |                 | No Effects      | 55.9%           |
| Wash            | 0.2793 (child   |                 |                 |
|                 | 1-6)            | No Effects      | 71.2%           |
|                 |                 |                 |                 |
|                 | 0.3558 (child   | No Effects      | 51.5%           |
|                 | 1-2)            |                 |                 |
|                 |                 |                 |                 |
|                 | 0.2573 (child   |                 |                 |
|                 | 3-5)            |                 |                 |
+-----------------+-----------------+-----------------+-----------------+

**Dietary risks were calculated in the above table for the U.S. general
population and for those groups exposed to the highest risk. The chronic
analyses were below the Agency's level of concern for all of the
Population Subgroups using the Agency DEEM. The most highly exposed
group was children 1-2 years old with 71.2% of the cPAD).**

**These residue calculations provide an acceptable dietary risk of
concern for population subgroups for this chemical.**

**[Issues That Must Be Resolved]{.underline}**

I. For the 40 CFR 180.940 Regulations for sanitizing solutions:

Many of the labels include uses for the sanitization of food serving
equipment, glasses, dishes, utensils and pots and pans. These surfaces
that have been treated with the dodecylbenzene sulfonate products may
bear small residues of the dodecylbenzene sulfonate Residues from
treated surfaces can migrate to food coming into contact with the
treated surfaces and can be ingested by humans.

Benzenesulfonic acid, dodecyl-: 40 CFR 180.940(c)

The site reads: "Food-processing equipment and utensils". The use
limitation is 400 ppm.

Benzenesulfonic acid dodecyl-, sodium salt: 40 CFR 180.940(c)

The site reads, "Food processing equipment and utensils". The use
limitation is 430 ppm equivalent to \~ 400ppm of the free acid.

Benzenesulfonic acid, dodecyl- : 40 CFR 180.940(b)

The site reads: "Dairy processing equipment, and food processing
equipment and utensils". The use limitation is 5.5 ppm.

It appears that dodecylbenzenesulfonic acid solutions containing up to
400 ppm can be used on dairy processing equipment and food processing
equipment. The registrant and user may have difficulty in distinguishing
between food processing equipment and dairy processing equipment. Many
labels bear use directions with a treatment rate of greater than 5.5 ppm
for dairy processing equipment.

Also, these 40 CFR citations also do not specifically state that the
solutions may be used on food contact articles including dishes, pots
and pans, glasses etc. However, there are many labels registered for use
on these sites.

**The Chemical Review Manager should ascertain the correct use sites and
limitations for these chemicals.**