UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

WASHINGTON, D.C. 20460 

JUN 102015 

OFFICE OF CHEMICAL SAFETY 

AND POLLUTION PREVENTION 

MEMORANDUM 

SUBJECT: 

FROM: 

THRU: 

TO: 

Pyrethroid and Pyrethrin Usage Data to Support the Down-the-Drain Assessment, 

DP # 426900 

Nikhil Ma llampalli, Entomologist ML fA fvtJ_._ 

Biological Analysis Branch 

Cynthia Doucoure, Environmental Protection ~~ Science Information and Analysis Branch 

Biological and Economic Analysis Division (7503P) 

Diann 

Science 

Sims, 

Jnfomrntion 

hi ef ~ and Ana lysis Branch 

Arnet Jones, Chief 

Biological Analysis ranch 

Biological and Economic Analysis ivision (7503 P) 

Garland Waleko, Chemical Review Manager 

Risk Management and Implementation Branch II 

Pesticide Re-evaluation Division (7508P) 

Product Review Panel Date: May 20, 2015 

SUMMARY 

In response to a request for available pyrethroid and pyrethrin indoor usage data to support the 

Pyrethroid Down-the-Drain (DtD) risk assessment, BEAD is providing estimates based on 

proprietary market survey databases. The most recent (20 11) data relevant to indoor residential 

pyrethroid and pyrethrin uses come from surveys of four market sectors: pest management 

professionals (PMPs) - also known as pest control operators (PCOs), consumer use for 

households and house plants, consumer use for pets, and consumer use of repellents. These data 

have been adjusted by BEAD to include only those estimates of amounts used indoors that are 

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expected to result in a down-the-drain exposure. These adjustments are described further on in 

this memorandum. BEAD concludes that overall, approximately 225,000 pounds a.i. of 

pyrethroids and pyrethrin (combined) are estimated to be used indoors annually in the U.S., in 

ways that have some likelihood of resulting in DtD exposure. BEAD considers this a very highend estimate; high-end values for individual active ingredients are listed in Table I (below). 

PYRETHROID and PYRETHRJN USAGE BY MARKET SECTOR 

BEAD used private market research data to determine the estimated amounts of pyrethroids used 

indoor in the U.S. by Pest Control Operators (PCOs) and consumers. The table below provides a 

summary of the available data for each sector. Note that in each sector, only a single year's 

survey is used; this is because these surveys are not conducted every year for every sector. These 

data are the most recent available to BEAD at this time. Following the table is a description of 

each market sector and the methods used by BEAD to calculate the estimate. 

T a bl c 1 DD t P ·yret h ro1 'd/P 'yr et h . u rm 

Active Ingredient (a.i.) 

Bifenthrin 

Cypem1ethrin 

Permethrin 

Deltamethrin 

d-Trans Allethrin 

lmiprothrin 

Lambda Cyhalothrin 

Cyfluthrin 

Pra ll ethrin 

Pyrethrin 

S-Bioallethrin 

Sumethri n 

Tetramethrin 

Tralomethrin 

Other a.i.s (#) 

Total (high-end estimate 

only) 

Source: Proprietary Data, 20 1 1 

Nr = not reported 

•consumer use on pets 

PCO 

14-32 

13-29 

4-10 

1-3 

nr 

nr 

1-3 

1-2 

nr 

nr 

nr 

nr 

nr 

nr 

4-8 

87 

sage: I d n oor R cs1 'd cnh. a I U SC b M 1y ar k et S ector 

Amount (1 ,000 lb a.i.) 

Consumer Total (high-end 

Household/Houseplant/Pets estimate only) 

0.06-0.1 32 

2-5 34 

3-7 17 

0.2-0.5 3.5 

0.06-0.1 0.1 

1-3 3 

0.06-0.1 3 

nr 2 

0.05-0.1 0.1 

89* 89 

1-2 2 

0.01-0.03 0.03 

0.5-1 1 

0.02-0.05 0.05 

13-28 36 

137 225 

(#) Includes prallethrin, pyrethrin, esfenvalerate, and d-trans allethrin, among other unspecified pyrethroids. 

Notes: (i) The range of figures in each row represents use estimated based on sales by PCOs for bedbugs 

(approximately 6 %) or cockroaches (approximately 12 %). Therefore, the "high end estimates" are based on the 

sales for cockroach control. For additional discussion, please see the discussion of "adjustment factors" below. 

(ii) Totals are rounded up to the nearest whole fi gure. 

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Use by Pest Control Operators 

Survey results indicate that the majority of pyrethroid/pyrethrin use (71 %) by PCOs is directed at 

residential use. The largest pest market segment is classified as "general insect control," which 

includes ants, cockroaches, fleas and bed bugs primarily. Sales of products for general insect 

control (minus exterior pests) constitute 55% of total sales of insecticides. The leading indoor 

application methods used by PCOs for general insect control are crack and crevice applications 

followed by concentrate sprays inside. For this DtD assessment, crack and crevice pose a lower 

potential for substantive release to water destined for publicly owned treatment works (POTWs). 

However, in the survey data available to BEAD, the percentage of sales or pounds used by PCOs 

is not broken down in terms of application method. Il is described in terms of target pest category 

(flies, cockroaches, bedbugs, etc.). These details were used by BEAD to adjust overall usage 

figures, as follows. 

Adjustment.factors for PCO use ofpyrethroids/pyrethrin 

BEAD's high-end estimate for the DtD assessment (Table I) was obtained by first determining 

the percentage of residential treatments by PCOs. According to proprietary data, 71 % of PCO 

sales is derived from products used in residential settings. To provide a reasonable refinement of 

this figure, BEAD took into account the percentage of sales for general pest control (55%) and 

the reported percentage of sales for the control of pests likely to result in DtD residues. BEAD 

believes that these pests include flies, cockroaches, and bed bugs, since these pests frequently 

occur near drains, or occur on materials, such as bedclothes, that could result in more frequent 

washing off of pesticide treatments (see, for example, Crenshaw and Peairs 2009, Layton 2013). 

A vai I able proprietary data shows that sales of products to control these pests range from 6-

13 .5%. These figures were used to determine the range of estimates of pyrethroid use by PCOs in 

residential settings. Sales for bedbugs fall within this range. 

Use by Consumers in Households, on Houseplants, and on Pets. 

For household/house plant insecticides, in 2011 pyrethroids accounted for the majority of 

consumer products that include 1 % or Jess of the active ingredient by weight. Frequently targeted 

pests of household insecticide sales are cockroaches, mosquitoes, ants, fleas, and flies in and 

around the home. Frequently targeted pest of houseplant insecticides are red spider mites, scales, 

aphids, white flies, mealybugs, and "other [unspecified] pests". The formulations used to control 

these pests are aerosol products predominantly, followed by baits, liquid concentrates, and readyto-use sprays. 

For consumer use on pets, pyrethrin represents 18% of the active ingredients used in pet 

products, primarily in shampoos, powders and sprays. In 2011 , available data show that 111 ,000 

pounds of pyrethrin were used in pet products. For pet insecticides, liquid products (shampoos, 

dips, and topical spot-ons/vet medications) represent 78% of the market, followed by tablets for 

veterinary use ( 15%) and collars (5%) and other (2%). 

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Adjustment factors for consumer household use ofpyrethroidslpyrethrin 

Regarding data for consumer use in households and house plants, BEAD believes that baits and 

foggers pose a lower potential for substantive release of residues to POTWs. Therefore, sales for 

these application methods was excluded from the estimates shown in Table 1. The remaining 

product formulations constitute 64% of sales of household/house plant insecticides. Detailed 

survey figures for pyrethroid sales in this market sector are not available for specific target pests. 

However, since target pests for consumers include flies, bedbugs, and cockroaches, BEAD used 

the figures reported for the PCO sector in the same way to further adjust the estimates for 

consumer household use, as reported in Table 1. 

For the "consumer pet" market sector, BEAD assumed that tablets and collars have lower 

potential for substantive release to POTWs. Therefore, the percentage of sales reported for these 

formulations was excluded from the figure reported for this sector in Table 1. Thus, to calculate 

the amount of pyrethrin used, BEAD reduced the total pounds a. i. of pyrethrin by applying a 

factor of 80% to the pyrethrin amount reportedly used by consumers. The final estimate of 

pyrethrin use on consumer pets is 89,000 lbs a. i. as shown in Table 1. 

BEAD also notes that "other active ingredients" used in pet products represent 37% of the 

"consumer pet" market sector. However, the exact amounts of the pyrethroids were not 

disclosed for this figure. Therefore, BEAD is unable to provide more specific data on pyrethroid 

use in the consumer pet market for the down-the-drain assessment, beyond the usage data for 

pyrethrin described above. 

Consumer Repellents 

For consumer repellents, proprietary data indicate that DEET continues to be the predominant 

active ingredient used in 201 1, followed by picaridin. The category of "other repellents" used in 

the consumer repellent market totaled 1.9 million pounds a.i. Permethrin, which was one 

component of "other repell ents," was reported to be used when applied to clothing, but the 

estimated amount used is not disclosed in the proprietary data. Therefore, in the absence of 

more speci fie data, BEAD does not have an estimate of pyrethroid usage in the consumer 

repellent market, and so this type of use is not included in Table I. 

CONCLUSIONS 

BEAD has reviewed the most recent available proprietary data to provide best available 

estimates of indoor pyrethroid use in the PCO and consumer markets to support the DtD 

pyrethroid assessment. In reporting these estimates, BEAD considered only the uses (in terms of 

application site, application method, and/or target pest, depending on the market sector) with 

higher potential for substantive release of pyrethroids into domestic wastewater. Following these 

adjustments, BEAD estimates that approximately 225,000 pounds of pyrethroids and pyrethrin 

are used annually indoors. BEAD believes that this is a very high-end estimate, since it assumes 

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that all indoor treatments targeting flies, bedbugs, and cockroaches are equally likely to result in 

DtD exposure every time an application is made. 

REFERENCES CITED 

Crenshaw, W.S. and F.B. Peairs. 2009. Flies in the Home. Fact Sheet No. 5.502 of the Colorado 

State University Extension service. Available on the web at: 

http://ww,.v.ext.colostate.edu/pubs/insect/05502.html [Accessed May 2015]. 

Layton, B. 2013. Control Household Insect Pests. Pub. No. 2443 of the Mississippi State 

University Extension Service. Available on the web at: 

http://msucares.com/insects/home/ [Accessed May 20 15). 

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