Wildlife Services Tech Note 

Sodium Lauryl Sulfate: European Starling and Blackbird Wetting Agent

European starlings (Sturnus vulgaris) and various blackbird 

species sometimes roost in areas where they can cause 

agricultural, health, and esthetic problems. Concerns 

associated with these roosts include increased noise levels, 

fecal accumulation, and disease threats. These birds can also 

compete with other avian species for resources. For example, 

introduced starlings compete with native birds for nest sites. 

Brown-headed cowbirds (a type of blackbird) are known to 

parasitize songbird nests and may be a major factor in the 

decline of neotropical migratory birds, such as the 

endangered Kirtland’s warbler. 

Employees of the U.S. Department of Agriculture’s (USDA) 

Wildlife Services (WS) program are often asked by State 

agencies, municipalities, business owners, and landowners

for assistance with dispersing or removing starling and 

blackbird roosts. 

This tech note describes the use of sodium lauryl sulfate (SLS) 

as a wetting agent in managing European starling; red-winged, 

yellow-headed, and Brewer’s blackbird; cowbird; grackle; 

American crow; common raven; and magpie roosts. SLS is a 

surfactant commonly used in soap products. When applied to 

birds, SLS allows water to penetrate and saturate the feathers 

so that with low temperatures (less than 41 °F) and sufficient 

water, birds die of hypothermia. 

This product is for use on upland roosts located away from 

bodies of water. In some situations, this tool may be an 

appropriate alternative to the registered avicide DRC–1339. 

Use Requirements From the Environmental 

Protection Agency 

In 1996, the U.S. Environmental Protection Agency (EPA) 

exempted 31 minimum-risk pesticides from requirements of 

the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) 

if the pesticides satisfy certain conditions. In general, 

conditions for claiming that a pesticide should be exempt 

from registration under FIFRA Section 25 (b) are that claims 

cannot be made regarding control of public-health pests, and 

the product cannot be used on food or feed crops. SLS 

(Chemical Abstract Service No. 151-21-3) was included on 

the list of 31 exempt compounds. Individual States retain 

the right to accept EPA’s regulatory exemption or to require 

State registration. 

Efficacy Data 

From 2004 to 2007, WS’ National Wildlife Research Center and 

Missouri State office conducted outdoor cage, flight-pen, and 

small-scale field tests to investigate the effectiveness of SLS in 

removing urban blackbird roosts. Results document that SLS 

causes mortality in European starlings, red-winged blackbirds, 

common grackles, and brown-headed cowbirds and may be 

useful as part of integrated wildlife damage management 

programs designed to reduce local blackbird populations. 

Birds died as soon as 30 minutes after exposure to SLS.

Ingredients

• Sodium lauryl sulfate: 28–30%

• Water: 70–72%

A copy of this tech note and the material 

safety data sheet (MSDS) must be in the 

possession of any WS employee or official 

cooperator applying SLS.
Obtaining SLS

SLS may be purchased in powder form and mixed with water at 

28-30% w/w SLS (CAS No. 151-21-3). If purchasing a pre-mixed

liquid solution of 28-30% SLS, the product must consist solely 

of SLS and water. 

Application Description

Before using SLS, please review the Applicator’s Checklist and 

system schematic included at the end of this tech note.

Equipment

The following is an example of equipment used to develop one 

ground-based spray system.

 Pump

 Pacer 5.5-hp Briggs and Stratton pump (gas) or 

equivalent

 2-inch T-coupler (for connecting SLS line to water 

supply line)

 Quick-fit couplers for hose and pump

 Water-pressure gauge

 2-inch-diameter supply hose from the water source to 

the pump

 1-inch-diameter supply hose from the SLS to the 

pump

 1.5-inch-diameter rolled hose from pump to spray 

system

 Two 2-inch ball valves for SLS and water supply lines

 Sprayer

 Wobbler Standard Angle nozzle, 24 degree angle and 

0.55 cm (7/32 inch) (Senninger Irrigation Inc., 

www.senninger.com) or equivalent

 Bell adaptor, 3/4 inch to 1 inch in diameter, to attach 

sprinkler head to pipe

 Three 10-foot sections of 1-inch-diameter steel or 

aluminum pipe with threaded ends (stand pipe)

 One four-legged sprinkler tower base

 Three 24-inch rebar anchors for base and guy wires

 Guy wire

 Three guy-wire plates 

 Other

 5 gallons of SLS and water mixture

 SLS transport cooler

 One 10-foot Y-tipped pole (to help raise sprinkler tower)

 Wrenches for couplers

 Silicon tape for stand-pipe joints

 Water source of 6 gallons per minute and a total of 

500 gallons per sprinkler head

 Portable temperature and wind gauges

 Data sheet

 Trash bags

 Rakes and shovels for bird pickup

 Personal protective equipment for each worker 

handling SLS (impervious gloves and goggles or a 

face shield) and birds (impervious gloves)

Pumping System Requirements

The pump must be able to deliver 500 gallons of water at a 

rate of 6 gallons per minute per sprinkler head. Operating 

below 6 gallons per minute is not recommended. A pressure 

gauge should be installed on the outlet pipe near the pump in 

order to monitor the flow rate. The pressure needed to 

operate the system effectively can be calculated with the 

following formula: 

For example, a 30-foottower would require 30/2.3 +15 + 10 = 38 psi 

to achieve the necessary flowrate. The psi will not change if more 

towers of the same height are included; however, the pump must 

be capable of delivering the necessary water at 38 psi. Multiple 

sprinkler heads should not be run in series. 

Flow rates should be adjusted before application and checked 

during application using the pressure gauge. Run the pump at 

the desired pressure during the entire application. If the flow 

rate is too high or low, throttle the pump to the desired level 

until the correct pressure is achieved. 

Testing has been done with up to four sprinkler-head spray 

systems running off one pump. Placement of more than four 

systems in a roost will require increasing the size of the pump 

or adding more pumps and increasing the water source.

psi = H/2.3 ft/psi + 15 psi + 10 psi

H = height of tower in feet

15 psi = minimum operating pressure for sprinkler head

10 psi = friction loss in system
Applying SLS to Roosting Birds

The following steps describe the application of SLS and water 

through a ground-based sprinkler-head spray system. Other 

application techniques (e.g., aerial, water cannon, or handheld wand) have not been tested. These steps are in 

compliance with FIFRA 25(b) exemption requirements.

1. Ensure that the top of the stand pipe is higher than the 

top of the roosting vegetation to be sprayed. The system 

has been tested up to a height of 30 feet.

2. Build the system(s) in areas of the roost where they will 

be most effective in bird coverage and need minimum 

supply hose. The spray area for one nozzle is about 

2,000 ft2 (a 50-foot-diameter circle).

3. To build a single system, attach a sprinkler head to the 

end of a 10-foot section of 1-inch-diameter aluminum or 

steel pipe.

4. As the three sections of pipe are connected together with 

couplers, place a guy-wire plate above each coupler with 

three attachment points evenly spaced around the plate.

5. Make sure the base is a four-legged "pyramid"-style frame 

that supports the standpipe. The base should have a 90° 

elbow section of pipe welded in the center so that the 

upright standpipe can be coupled to the supply line (fig. 1).

6. Once you’ve assembled the sections on the ground and 

attached guy wires to the plate, have two people raise the 

tower by pulling on the guy wires while a third person 

supports the tower by hand (fig. 2). A 10-foot pole with a 

“Y” on the end can be helpful to raise the towers.

7. Secure guy wires at a 30° angle from the standpipe and 

attach them to rebar anchors driven into the ground 

about 18 inches.

8. Once you’ve built a system, move all equipment and

personnel at least 200 feet away to avoid being sprayed by 

the SLS solution or disturbing the birds.

9. The pump is attached to the system using 1.5-inch rolled 

hose. If you use more than two systems, attach the supply 

line to a central system and branch out to all sprinkler 

systems. Do not run the supply line in series—this will 

reduce pressure to each successive sprinkler.

10. Attach a supply of water (at least 500 gallons of water per

sprinkler head) to the pump with a 2-inch-diameter 

flexible hose. Water trailers containing 1,000 gallons or 

more work well and can be transported to the site. The 

recommended distance between the pump and sprinkler 

head is 400 feet.

11. Connect a 1-inch-diameter supply line for the SLS to 

the pump. You can fit two supply lines to the pump with 

a “T” fitting with on/off valves on each side (fig. 3). All 

connections should be “quick-connect fittings” for ease 

of assembly and disassembly.

12. Test the sprinkler system before birds arrive at the roost 

to make sure it’s working properly.

Figure 1. SLS base

Figure 2. Positioning the SLS sprayer may require three or more people.

Figure 3. SLS pump
13. Close or slow down the system so water is barely running 

out of the top to avoid letting any air siphon back into the 

lines. Any noise during the spray procedure, such as air 

leaving the sprinkler head(s) or guy wires hitting the pipe, 

will cause birds to flush.

14. For best results, ambient air temperature should be 

below 41 °F at the time of application and immediately 

afterward. Do not spray when the wind exceeds 20 miles 

per hour; doing so will cause significant drift and 

incomplete coverage of the target area.

15. About 30 minutes after birds have settled into the roost, 

begin the spray operation.

16. Bring the system up to operating pressure slowly to 

reduce the amount of noise generated by air escaping 

the system.

17. Once the birds have become accustomed to the water, 

slowly introduce SLS into the system through the supply 

line. (Note: The SLS must remain heated above 70 °F 

before use. See suggestions on how to do this at right 

under “Storing SLS.”)

18. To inject SLS into the system, slowly open the SLS supply 

line so water can back-fill the line and expel any air.

19. Once the SLS supply line has been purged of air, slowly 

close the water supply line while keeping the SLS supply 

line completely open. During this part of the operation, 

if at any time you see birds flush or leave the roost, close 

the SLS supply line and open the water supply line. 

Only reintroduce the SLS after the birds have settled 

back down.

20. After injecting the SLS into the system, close the SLS 

supply line while opening the water supply line. In total, 

about 5 gallons of SLS should be sprayed per system.

21. Continue spraying until two-thirds of the birds are dead or 

dying or until the water runs out.

22. Do not disturb the birds during the spray operation.

Observe the roost through binoculars from at least 200

feet away to ensure that the birds are not flushed from 

the roost.

Storing SLS

At a minimum, all containers of the SLS mixture must have a 

product label that lists the two ingredients and their weight 

concentration (% w/w), as well as the address and phone 

number of the company for which the product was produced. 

All storage facilities must have a current Safety Data Sheet for 

the SLS available. Follow the storage instructions indicated on 

the original SLS product's label. 

Important: The SLS mixture solidifies at temperatures below 

55 °F. SLS must remain heated above 70 °F before and 

during use to ensure proper flow throughout application. This 

can be accomplished by leaving SLS in a heated vehicle until 

injecting it into the system.

Evaluating Roost Mortality

After the spray operation, you must estimate roost mortality 

to fulfill requirements of the depredation order, State 

depredation permit, and/or the WS Management Information 

System and evaluate the operation’s overall success. Data 

gathered should include the number and type of each 

species, total weight of birds collected, and the average 

weight per bird.

For More Information

National Wildlife Research Center

Wildlife Services

Animal and Plant Health Inspection Service

U.S. Department of Agriculture

4101 LaPorte Avenue

Fort Collins, CO 80521

(970) 266–6000

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Mention of companies or commercial products does not imply recommendation or endorsement by

USDA over others not mentioned. USDA neither guarantees nor warrants the standard of any product mentioned.

Product names are mentioned solely to report factually on available data and to provide specific information.

This publication reports research involving pesticides. All uses of pesticides must be registered 

by appropriate State and/or Federal agencies before they can be recommended.

CAUTION: Pesticides can be injurious to humans, domestic animals, desirable plants, and fish or other wildlife—

if they are not handled or applied properly. Use all pesticides selectively and carefully. Follow recommended 

practices for the disposal of surplus pesticides and pesticide containers.

WS-21-001 | Revised November 2021
USDA is an equal opportunity provider, employer, and lender.

WS-21-001A | Revised November 2021

Applicator’s Checklist for Sodium Lauryl Sulfate

 Ensure that the take of birds is consistent with depredation orders, State and Federal permitting 

requirements, and/or other authorities.

 Contact the appropriate State regulatory agency to confirm that sodium lauryl sulfate (SLS) can be used in 

the State under a Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) Section 25(b) exemption. Not all 

States accept the U.S. Environmental Protection Agency (EPA) minimum-risk designation. You must submit a

wetting-agent product label and, in some cases, efficacy data to each State that does not accept the EPA 

minimum-risk designation for SLS.

 Consult with appropriate Federal and State wildlife authorities to ensure that the use of SLS presents no 

hazard to threatened or endangered species.

 Discuss the proper use of personal protective equipment with workers before removing bird carcasses after 

application. Develop a plan for disposing of bird carcasses. Large roosts can result in several tons worth of 

carcasses (10,000 birds weigh about 1 ton).

 Carry printed copies of this tech note and the material data safety sheet (MSDS). These items must be in the 

possession of any individual applying SLS.

 Use SLS as described in this tech note in order to meet FIFRA Section 25(b) exemption requirements.

 Limit applications to upland areas where direct runoff will not enter permanent bodies of water. SLS is considered 

moderately toxic to aquatic organisms. It can also impact aquatic organisms, such as mosquitoes and water 

spiders, by lowering the surface tension of the water. There is some evidence that SLS is harmful to plants. Use 

care when applying it around ornamental plantings.

 Monitor the spray area before application to determine if nontarget species are present. Nontarget birds, 

such as American robins and cardinals, may be affected if they roost in the spray area.