Report to the Ranking Minority 

Member, Committee on Government 

Reform, House of Representatives 

United States General Accounting Office 

GAO 

March 2003 PESTICIDES ON 

TOBACCO 

Federal Activities to 

Assess Risks and 

Monitor Residues 

GAO-03-485 
In the 1990s, domestic growers commonly used 37 pesticides approved 

for use on tobacco by EPA. Most of these pesticides were also used on 

food crops. When used in ways that deviate from conditions set by EPA, 

many of these pesticides can cause moderate to severe respiratory and 

neurological damage—and may result in death. Moreover, animal studies 

suggest that some of these pesticides may cause birth defects or cancer. 

Under its pesticide registration program, EPA evaluates toxicity and 

other data to assess health risks to workers and the public from exposure 

to pesticides—and risks to smokers from exposure to residues in smoke. 

These assessments have identified a range of risks that required such 

mitigation as limiting where and how the pesticide may be used, 

prohibiting use in certain states, and requiring workers to wear 

respirators and chemical-resistant clothing. On the other hand, EPA has 

concluded that low levels of residues in tobacco smoke do not pose 

short-term health concerns requiring mitigation. EPA does not assess 

intermediate or long-term risks to smokers because of the severity of 

health effects linked to use of tobacco products themselves. 

While EPA regulates the specific pesticides that may be used on tobacco 

and other crops and specifies how the pesticides may be used, it does not 

otherwise regulate residues of pesticides approved for use on tobacco. 

USDA, however, is required by the Dairy and Tobacco Adjustment Act to 

test imported and domestic tobacco for residues of pesticides not

approved by EPA for use on tobacco that federal officials believe are 

used in other countries. By helping ensure that other countries do not 

use highly toxic pesticides that U.S. tobacco growers may not use, 

federal regulation of pesticide residues on tobacco addresses trade 

equity as well as health and environmental issues. However, USDA has 

not reevaluated the list of pesticides for which it tests since 1989, even 

though EPA has cancelled tobacco use for over 30 pesticides since then. 

USDA Inspectors Take a Tobacco Sample for Laboratory Testing 

Pesticides play a significant role in 

increasing production of tobacco, 

food, and other crops by reducing 

the number of crop-destroying 

pests. However, if used 

improperly, pesticides can have 

significant adverse health effects. 

GAO was asked to (1) identify the 

pesticides commonly used on 

tobacco crops and the potential 

health risks associated with them, 

(2) determine how the 

Environmental Protection Agency 

(EPA) assesses and mitigates 

health risks associated with 

pesticides used on tobacco, and 

(3) assess the extent to which 

federal agencies regulate and test 

for pesticide residues on tobacco. 

GAO recommends that the 

Secretary of the Department of 

Agriculture direct the 

Administrators of the Agricultural 

Marketing Service and the Farm 

Service Agency to periodically 

review and update the pesticides 

on tobacco for which they set 

residue limits and test imported 

and domestic tobacco. 

Commenting on a draft of this 

report, EPA officials said GAO 

accurately characterized the 

agency’s risk assessment process 

for pesticides used on tobacco, and 

Department of Agriculture officials 

agreed with GAO’s 

recommendation to periodically 

review and update the pesticides 

for which the department sets 

residue limits and tests tobacco. 

www.gao.gov/cgi-bin/getrpt?GAO-03-485.

To view the full report, including the scope 

and methodology, click on the link above. 

For more information, contact John B. 

Stephenson at (202) 512-3841 or 

stephensonj@gao.gov. 

Highlights of GAO-03-485, a report to the 

Ranking Minority Member, Committee on 

Government Reform, House of 

Representatives 

March 2003 

PESTICIDES ON TOBACCO

Federal Activities to Assess Risks and 

Monitor Residues 
Page i GAO-03-485 Pesticides on Tobacco 

Letter 1

Results in Brief 2

Background 4

Pesticides Commonly Used on Tobacco Have Potential Short- and 

Long-Term Adverse Health Effects 7

EPA Concludes that Health Risks of Pesticide Residues on 

Tobacco Are Minimal but Requires Mitigation for Risks from 

Other Exposures 14

Federal Regulation of Pesticide Residues on Tobacco Is Limited 26

Conclusions 32

Recommendation for Executive Action 33

Agency Comments 33

Appendix I Objectives, Scope, and Methodology 35 

Appendix II Pesticide Use on Tobacco and Other Crops 37 

Appendix III Germany, Italy, and Spain Have Adopted Regulatory 

Limits for Pesticide Residues on Tobacco 39 

Appendix IV USDA Tests Domestic Tobacco in the Loan Stock 

Program 42 

Appendix V GAO Contacts and Staff Acknowledgments 44 

Tables 

Table 1: Pesticides Commonly Used on Domestic Tobacco, 1990-98 8

Table 2: Pesticide Use on Tobacco, 1990-98 9

Table 3: Organochlorine, Organophosphate, and Carbamate 

Pesticides Commonly Used on Tobacco in the 1990s 11

Table 4: Margins of Exposure for Five Pesticides Approved for Use 

on Tobacco 26

Table 5: USDA’s Residue Limits for Pesticides on Tobacco 29

Contents 
Page ii GAO-03-485 Pesticides on Tobacco 

Table 6: Pesticide Use on Tobacco and All Crops, 1990-98 37

Table 7: Residue Limits Adopted by Germany, Italy, and Spain for 

Pesticides Commonly Used on Tobacco in the United 

States during the 1990s 39

Figure 

Figure 1: EPA’s Tiered Approach to Assessing Health Risks of 

Exposure to Residues on Tobacco 17

Abbreviations 

1,3-D 1,3-dichloropropene 

2,4-D 2,4-dichlorophenoxyacetic acid 

2,4,5-T 2,4,5-trichlorophenoxyacetic acid 

AMS Agricultural Marketing Service 

CORESTA Cooperation Centre for Scientific Research Relative to 

Tobacco 

DBCP Dibromocloropropane 

DDE Dichlorodiphenyldichloroethylene 

DDT Dichlorodiphenyltrichloroethane 

EDB Ethylene dibromide 

EPA Environmental Protection Agency 

FDA Food and Drug Administration 

FFDCA Federal Food, Drug, and Cosmetic Act 

FIFRA Federal Insecticide, Fungicide, and Rodenticide Act 

FQPA Food Quality Protection Act 

FSA Farm Service Agency 

HCB Hexachlorobenzene 
Page iii GAO-03-485 Pesticides on Tobacco 

NCFAP National Center for Food and Agricultural Policy 

NCSU North Carolina State University 

ppm parts per million 

TDE Tetrachlorodiphenylethane 

TTR total toxic residue 

USDA U.S. Department of Agriculture 

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Page 1 GAO-03-485 Pesticides on Tobacco 

March 26, 2003 

The Honorable Henry A. Waxman 

Ranking Minority Member 

Committee on Government Reform 

House of Representatives 

Dear Mr. Waxman: 

As you know, pesticides are used regularly on food and nonfood crops, 

such as tobacco, to control a range of unwanted animal, plant, and 

microbial pests.1

 Trace amounts of pesticides, called residues, remain on 

tobacco and other crops after treatment. Typically, the residue levels on 

tobacco decline as the leaves are harvested, dried, and further processed 

into consumer products, and still further when the tobacco is burned. 

However, varying residue levels may remain. As a result, human exposure 

to pesticide residues on tobacco may occur when residues remaining in 

cigarette smoke are inhaled. While much is known about the significant 

health risks of using tobacco products, limited information exists on the 

extent to which the use of pesticides on tobacco may increase the 

considerable health risks associated with tobacco use itself. 

By controlling pests that reduce crop yields, pesticides can provide more 

abundant supplies of fruits, vegetables, and other crops. Nonetheless, 

pesticides are generally designed to be toxic to living organisms and thus 

can have significant adverse health effects if used improperly. The 

Environmental Protection Agency (EPA) determines whether and under 

what conditions pesticides can be used in the United States without posing 

an unreasonable risk to human health or the environment. Pesticides that 

meet EPA’s requirements are granted licenses or “registrations,” which 

permit their distribution, sale, and use according to specific directions and 

requirements identified on the labels. In addition, the U.S. Department of 

Agriculture (USDA) and the Food and Drug Administration (FDA) monitor 

crops for certain pesticide residues. 

 1

This report generally uses the term “pesticide” to refer to the toxic compounds, also called 

active ingredients, that are contained in pesticide products. Pesticide products typically 

include at least one active ingredient as well as inert ingredients. 

United States General Accounting Office

Washington, DC 20548 
Page 2 GAO-03-485 Pesticides on Tobacco 

In response to your request for information on how the federal 

government addresses the public health implications of pesticides on 

tobacco, this report describes (1) the pesticides commonly used on 

tobacco and the potential health risks associated with them; (2) how EPA 

assesses and mitigates health risks associated with pesticides used on 

tobacco; and (3) how, and the extent to which, federal agencies regulate 

and monitor pesticide residues on tobacco. Several pesticide use surveys 

conducted or sponsored by the federal government provide information on 

the types and amounts of pesticides commonly used on tobacco and other 

crops in the 1990s. These data, available through 1998, estimate average 

annual agricultural use of pesticides, excluding such uses as pest control 

in greenhouses. To determine how EPA assesses and mitigates health risks 

associated with pesticides used on tobacco, we reviewed, among other 

things, studies and documentation related to 13 pesticides commonly used 

on tobacco that EPA evaluated under its reregistration program between 

1994 and 2002. For more details on our scope and methodology, see 

appendix I. 

Surveys conducted during the 1990s indicate that tobacco producers in the 

United States commonly used 37 pesticides approved for such use by EPA, 

most of which were also approved for use on food crops. When used in 

ways that deviate from the conditions set by EPA, many of these 

pesticides can cause moderate to severe respiratory and neurological 

damage—and may result in death. Further, animal studies suggest that 

some of these pesticides may cause birth defects and cancer. About half of 

the pesticides used on tobacco work primarily by preventing the normal 

flow of nerve impulses to muscles and are among those most often 

implicated in poisonings, injuries, and illnesses. In humans, symptoms 

appear within minutes to hours after exposure and range from tightness in 

the chest, headache, nausea, and dizziness to death from respiratory 

failure. 

EPA bases its assessments of the health risks to both workers and the 

general population from exposure to the pesticides that are used on 

tobacco and other crops on its evaluation of a wide range of toxicity, 

residue, and other data. Workers are exposed through mixing and applying 

pesticides, and the general population is exposed through pesticide 

products used in the home and in public places and through pesticide 

residues in food and water. EPA also assesses the health risks to smokers 

from exposure to pesticide residues that remain in cigarette smoke by 

analyzing data on the toxicity of specific pesticides and the residue levels 

that remain on tobacco and in tobacco smoke. EPA’s assessments of risks 

Results in Brief 
Page 3 GAO-03-485 Pesticides on Tobacco 

to workers and the public from exposure to pesticides that are used on 

tobacco and other crops have identified a range of potential adverse health 

effects. To mitigate such effects, EPA has set special limitations on where 

and how some pesticides may be used, such as requiring workers who use 

them to wear respirators and chemical-resistant clothing, prohibiting their 

use in certain states to avoid high pesticide levels in groundwater used for 

drinking, and not permitting certain uses at all. On the other hand, EPA 

has generally concluded that the low levels of residues measured in 

tobacco smoke do not pose short-term health concerns. EPA does not 

assess the additional risk of either intermediate- or long-term exposure to 

pesticide residues in smoke because of the severity and quantity of health 

effects associated with the use of tobacco products themselves. In 

addition, the agency does not include short-, intermediate-, or long-term 

exposure to residues on tobacco in its assessments of total exposures to 

the pesticides. Officials and experts with whom we spoke generally agreed 

that pesticide residues on tobacco could incrementally increase health 

risks, though some also said the known harm from using tobacco products 

dwarfs any potential effect from exposure to pesticide residues in the 

smoke. 

While EPA regulates the specific pesticides that may be used on tobacco 

and other crops and specifies how the pesticides it approves may be used, 

EPA does not otherwise regulate the residues of pesticides approved for 

use on tobacco and other nonfood crops. USDA, however, is required by 

the Dairy and Tobacco Adjustment Act, as amended, to test domestic and 

imported tobacco for pesticides not approved for use on tobacco by EPA. 

As a result, federal regulation of pesticide residues on tobacco is limited to 

selected pesticides that are not approved by EPA for such use in the 

United States. USDA tests most imported tobacco, as well as the portion of 

domestic tobacco the federal government acquires under the tobacco 

price support program, for residues of 20 pesticides not approved for use 

on tobacco that federal officials believe are used in some other countries. 

Most of these pesticides, such as DDT, are highly toxic, persist in the 

environment, and accumulate in the bodies of humans and animals.2

 By 

helping to ensure that other countries do not use pesticides that U.S. 

tobacco growers are not allowed to use, the federal regulation of pesticide 

residues on tobacco addresses trade equity as well as health and 

 2

Dichlorodiphenyltrichloroethane, known as DDT, was one of the most widely used 

chemicals for controlling insect pests on crops after 1945. Under the authority of EPA, all 

registrations of DDT have been cancelled, prohibiting the use of the pesticide in the United 

States. 
Page 4 GAO-03-485 Pesticides on Tobacco 

environmental issues. USDA has not reevaluated since 1989 the pesticides 

the department monitors in its tobacco pesticide residue testing program, 

although EPA has subsequently cancelled tobacco uses for at least 30 

pesticides not currently monitored by USDA. Consequently, USDA’s 

testing program excludes some highly toxic pesticides that may still be 

used in other countries. To better protect the public from residues not 

approved for use on tobacco, we are recommending that USDA 

periodically reevaluate the pesticides it includes in its testing program. 

Tobacco is a high-value, pesticide-intensive crop. That is, tobacco is the 

nation’s ninth highest valued crop, and in terms of the amount of pesticide 

applied per acre, tobacco ranks sixth—behind potatoes, tomatoes, citrus, 

grapes, and apples. In the United States, tobacco is grown in 16 states, 2 of 

which—Kentucky and North Carolina—produce about two-thirds of all 

domestic tobacco.3

 Further, it is grown in over 100 countries. Until 

recently, the United States was the world’s leading exporter of 

unmanufactured tobacco; however, in 2001, it ranked third, behind Brazil 

and Zimbabwe. The tobacco industry in the United States both exports 

tobacco to Japan and Western Europe—principally Germany, the 

Netherlands, Denmark, the United Kingdom, Belgium, Italy, and Spain—

and imports tobacco in increasing amounts from countries such as Brazil, 

Argentina, Malawi, and Thailand. Furthermore, the United States is the 

second largest producer of cigarettes in the world, following China. More 

than 90 percent of the tobacco grown in the United States is used to 

manufacture cigarettes, as is most tobacco produced in the world. The 

remainder is used for chewing tobacco, snuff, cigars, and pipe tobacco. 

Tobacco types are often defined by such characteristics as how the 

tobacco is cured (flue-, air-, or sun-cured), as well as the color, size, and 

thickness of the leaves. Different types of tobacco are used in the various 

tobacco products. The tobacco component of cigarettes made in the 

United States usually consists of flue-cured and burley tobacco blended 

with imported oriental tobacco and small amounts of specialty tobaccos 

grown in Maryland and Pennsylvania.4

 3

The 14 other states are Connecticut, Florida, Georgia, Indiana, Maryland, Massachusetts, 

Missouri, Ohio, Pennsylvania, South Carolina, Tennessee, Virginia, West Virginia, and 

Wisconsin. 

4

In addition to tobacco, cigarettes contain other ingredients (additives) to enhance flavor 

and other qualities of the product. 

Background 
Page 5 GAO-03-485 Pesticides on Tobacco 

Although pesticides play a significant role in increasing production of 

tobacco, food, and other crops by reducing the number of crop-destroying 

pests, exposure to pesticides can harm humans. The potential for harm is 

related to both the amount of a substance a person is exposed to—the 

dose—and the toxicity of the chemical. For example, small doses of 

aspirin can be beneficial to people, but at very high doses, this common 

medicine can be deadly. Furthermore, in some individuals, even at very 

low doses, aspirin may be lethal. The age and health status of an individual 

can also affect the potential for harm. Children may be more susceptible to 

harm because, for example, they eat more food, drink more water, and 

breathe more air than adults per pound of body weight, resulting in greater 

exposure. Generally, assessments of dose and response involve 

considering the dose levels at which adverse effects are observed in test 

animals and using these dose levels to calculate an equivalent dose in 

humans. 

In many cases, exposure to pesticides is through residues that remain on 

crops following use of the pesticides. The amount of pesticide residue that 

remains reflects, among other things, the amount of pesticide applied, the 

time lapsed since application, and the speed with which the pesticide 

dissipates in the environment. Residue levels remaining on crops are also 

affected by where the pesticides are applied, such as in the soil or on the 

plant, and when they are used in the life cycle of the plant, such as when 

the plant is a seedling or shortly before the plant is harvested. Typically, 

residues on tobacco decline as the plant moves from field to finished 

consumer product. 

The primary federal requirements pertaining to the registration, sale, and 

use of pesticides are in the Federal Insecticide, Fungicide, and 

Rodenticide Act (FIFRA) and the Federal Food, Drug, and Cosmetic Act 

(FFDCA), both as amended by the Food Quality Protection Act (FQPA). 

Pesticides must generally be registered with EPA in order to be sold or 

distributed. EPA will register a pesticide if it determines, among other 

things, that the pesticide will not generally cause unreasonable adverse 

effects on human health or the environment when used in accordance with 

conditions specified on the label. Throughout this report we will focus on 

EPA’s analysis of potentially harmful effects to human health, rather than 

the environment. 

In 1988 FIFRA was amended to require that EPA review pesticides initially 

registered prior to November 1984—when less toxicity data were 

available—to consider their health effects and to determine whether and 

how they might continue to be registered. These reviews are designed to 
Page 6 GAO-03-485 Pesticides on Tobacco 

ensure that older pesticides meet contemporary health and safety 

standards and that their risks are mitigated. Essentially, manufacturers of 

the older pesticides must provide EPA with substantially the same 

toxicity, chemistry, and other data as are now required to register a new 

pesticide.5

 EPA reviews of the older pesticides are called reregistrations. 

Most of the pesticides used on tobacco during the 1990s were initially 

approved before 1984 and therefore are subject to reregistration. 

In addition, the FQPA amendments to FIFRA passed in 1996 require EPA 

to reevaluate the amounts of pesticide residues allowed on or in food—

known as tolerances. EPA must ensure that there is a reasonable certainty 

that no harm will result from all pesticide exposures from food and 

nonfood uses for which there is reliable information. In doing so, unless 

another safety factor is determined to be appropriate, EPA is required to 

apply an additional 10-fold safety factor in setting tolerances to ensure the 

safety of foods for children. EPA is also required to ensure that there is 

reasonable certainty that no harm will result to children specifically from 

“aggregate” exposure to a single pesticide—that is, from all sources, such 

as lawn treatments, household uses, drinking water, and food. EPA must 

also consider available information concerning the cumulative effects on 

children of pesticides that act in a similar harmful way (known as a 

common mechanism of toxicity). To accomplish this requirement, EPA 

has recently developed a method to evaluate the cumulative exposure of 

one class of highly toxic pesticides—the organophosphates—from 

residues in food and drinking water and from residential uses. 

EPA uses risk assessment—the systematic, scientific description of 

potential adverse effects from exposure to hazardous substances—to 

evaluate the potential health impacts of a pesticide on humans and 

determine what measures are needed to mitigate identified risks. The 

product of a risk assessment is an identification of the various health risks, 

along with quantitative and/or qualitative statements regarding the 

probability that an exposed population will be harmed and to what degree. 

For example, EPA qualitatively classifies pesticides and other toxic 

substances according to their potential to cause cancer using descriptors 

such as “likely” or “suggestive evidence but not sufficient to assess human 

carcinogenic potential.” In addition, for many carcinogens, EPA develops a 

quantitative dose/response health risk assessment that estimates the 

 5

Typically, applicants for pesticide registrations are the manufacturers; EPA calls the 

applicants “registrants.” 
Page 7 GAO-03-485 Pesticides on Tobacco 

health risks at varying exposures. For health effects other than cancer, 

EPA may calculate what it terms a “reference dose” or, in the case of 

exposure by inhalation, a “reference concentration,” which represents a 

daily level of exposure that is unlikely to result in harm over a lifetime. 

Alternatively, EPA may calculate a “margin of exposure,” which is a ratio 

that shows how far the actual (or estimated) human exposure to a 

substance is from levels that are harmful. In essence, evaluating and 

managing the risk of exposure to a pesticide involves determining the 

maximum safe level of exposure to the pesticide and assessing whether 

expected actual exposure is below this maximum level. If expected actual 

exposure levels exceed the maximum safe amount, EPA must determine 

the best ways to reduce exposure. 

According to federally sponsored surveys, during the 1990s tobacco 

producers in the United States commonly used 37 of the pesticides 

approved by EPA for such use.6

 As shown in table 1, most of the pesticides 

used on tobacco were insecticides and herbicides, which control insect 

and plant pests; others were fungicides, which combat fungal diseases, or 

plant growth regulators; and a few had more than one use.7

 6

The National Center for Food and Agricultural Policy, a private nonprofit, nonadvocacy 

research organization, conducted two key surveys for USDA covering the periods 1990-93 

(called the 1992 survey) and 1994-98 (called the 1997 survey). See appendix I for more 

detail on these surveys. 

7

In this report, the term “insecticide” includes pesticides used to control insects, spiders, 

and nematodes (worms). 

Pesticides Commonly 

Used on Tobacco 

Have Potential Shortand Long-Term 

Adverse Health 

Effects 
Page 8 GAO-03-485 Pesticides on Tobacco 

Table 1: Pesticides Commonly Used on Domestic Tobacco, 1990-98 

Primary use(s) Pesticide 

Insecticide Acephate, aldicarb, Bacillus thuringiensis, carbaryl, 

carbofuran, chlorpyrifos, diazinon, disulfoton, 

endosulfan, ethoprop, fenamiphos, fonofos, 

imidacloprid, malathion, methidathion, methomyl, 

spinosad, trichlorfon 

Herbicide Benefin, clomazone, diphenamid, isopropalin, 

napropamide, pebulate, pendimethalin, sethoxydim, 

sulfentrazone 

Fungicide Dimethomorph, mancozeb, mefenoxam, metalaxyl 

Plant growth regulator Ethephon, flumetralin 

Plant growth regulator, herbicide Maleic hydrazide 

Fumigant, insecticide Chloropicrin 

Fumigant, insecticide, herbicide Methyl bromide 

Fungicide, insecticide, herbicide 1,3-dichloropropene (1,3-D) 

Source: EPA, International Organization for Standardization, National Center for Food and Agricultural Policy, and USDA. 

Note: GAO’s analysis of EPA, International Organization for Standardization, National Center for 

Food and Agricultural Policy, and USDA data. 

Most of these pesticides were also widely used on food crops. The actual 

number and amount of pesticides used on tobacco or other crops in any 

given year vary depending on factors such as the weather and the specific 

pests that become problematic. For example, the incidence of many plant 

diseases is closely correlated to the amount of rainfall, resulting in greater 

use of fungicides in years with high rainfall. In addition, pesticide use 

tends to change over time as pests develop resistance to the pesticides and 

as use on tobacco is approved for new pesticides and cancelled for older 

pesticides.8

 As table 2 shows, 10 pesticides identified in the 1997 survey as 

commonly used on tobacco were not identified in the earlier survey. Two 

of these pesticides, dimethomorph and mancozeb, began to be used in 

response to the appearance of a disease resistant to metalaxyl, which 

declined in usage during the 1990s. In addition, during the years included 

in the 1997 survey, tobacco use for 5 of the 7 pesticides no longer reported 

as being used—diazinon, diphenamid, isopropalin, methidathion, and 

trichlorfon—was being cancelled.9

 In some cases, pesticide cancellations 

resulted in the increased use of other pesticides. For example, by 1997 

clomazone had replaced diphenamid and isopropalin as the pesticide of 

 8

During the 1990s, EPA cancelled tobacco use for approximately 34 pesticides. 

9

When EPA cancels the use of a pesticide, the pesticide is typically phased out over time. 
Page 9 GAO-03-485 Pesticides on Tobacco 

choice for controlling unwanted weeds, and imidacloprid was most 

commonly used to control insect pests, leading to reduced use of 

acephate, aldicarb, chlorpyrifos, ethoprop, and carbofuran. Manufacturers 

may initiate cancellation of some or all uses of a pesticide, often for 

economic reasons,10 or EPA may cancel uses when the agency determines 

that one or more uses pose unreasonable risks to human health or the 

environment. For example, as required under the Clean Air Act, EPA has 

been phasing out the use of methyl bromide on tobacco and a wide range 

of other crops because it depletes the earth’s protective layer of ozone.11

Methyl bromide use on tobacco decreased from about 5.4 million pounds 

in 1992 to about 0.7 million pounds in 1997 because of EPA’s efforts and 

changes in how tobacco producers raise seedlings. Specifically, producers 

have begun to grow tobacco seedlings in greenhouses, where methyl 

bromide is not generally used. 

Table 2: Pesticide Use on Tobacco, 1990-98 

Pesticide 

Pounds used on tobacco 

1992 survey (1990-93) 

Pounds used on tobacco 

1997 survey (1994-98) 

1,3-dichloropropene (1,3-D) 11,537,540 13,279,285 

Chloropicrin 577,082 6,761,644 

Maleic hydrazide 1,789,208 1,790,089 

Acephate 1,570,457 871,899 

Methyl bromide 5,356,748 685,026 

Pendimethalin 321,931 473,718 

Chlorpyrifos 685,554 406,822 

Fenamiphos 257,142 379,841 

Mancozeb a 356,811 

Flumetralin a 352,742 

Metalaxyl 371,645 271,368 

Clomazone a 217,617 

Ethoprop 438,274 182,321 

Endosulfan a 172,766 

Mefenoxam a 139,199 

Pebulate 412,000 131,665 

Ethephon 113,238 102,130 

 10One reason manufacturers may choose to request cancellation of pesticide registrations is 

to avoid costs associated with reregistering pesticides for each use, such as the cost of 

providing EPA with data and studies. 

11EPA’s efforts to phase out the use of methyl bromide in the 1990s were consistent with 

international efforts to curtail its use under the Montreal Protocol, a treaty signed by over 

160 countries to control the production and trade of ozone-depleting substances globally. 
Page 10 GAO-03-485 Pesticides on Tobacco 

Pesticide 

Pounds used on tobacco 

1992 survey (1990-93) 

Pounds used on tobacco 

1997 survey (1994-98) 

Napropamide 191,840 92,622 

Sulfentrazone a 69,073 

Imidacloprid a 67,896 

Aldicarb 159,044 59,719 

Dimethomorph a 36,818 

Methomyl 57,137 29,773 

Malathion 7,549 15,437 

Disulfoton 52,578 13,495 

Sethoxydim a 9,579 

Spinosad a 2,815 

Carbaryl 16,487 2,057 

Fonofos 12,798 16 

Benefin 56,963 a 

Bacillus thuringiensis b b 

Carbofuran 149,965 a 

Diazinon 53,670 a 

Diphenamid 81,624 a 

Isopropalin 129,287 a 

Methidathion 68 a 

Trichlorfon 722 a 

Total used on tobacco 24,400,552 26,974,241 

Source: National Center for Food and Agricultural Policy. 

a

Not identified as being used in the survey. 

b

Neither survey estimated the use of Bacillus thuringiensis in pounds. 

EPA determines the amounts and conditions under which a pesticide may 

be used so that it will not pose unreasonable risks to workers or the 

general population. Failure to comply with the conditions set by EPA 

could result in a range of harmful effects. For example, 17 of the 37 

pesticides commonly used on tobacco in the 1990s belong to three 

chemical classes that, at high doses, are known to cause adverse human 

health effects up to and including death (see table 3). 
Page 11 GAO-03-485 Pesticides on Tobacco 

Table 3: Organochlorine, Organophosphate, and Carbamate Pesticides Commonly 

Used on Tobacco in the 1990s 

Chemical class Pesticide name 

Organochlorine Endosulfan 

Organophosphate Acephate, chlorpyrifos, diazinon, disulfoton, ethoprop, fenamiphos, 

fonofos, malathion, methidathion, trichlorfon 

Carbamate Aldicarb, carbaryl, carbofuran, mancozeb, methomyl, pebulate 

Source: EPA, National Center for Food and Agricultural Policy, and USDA. 

Note: GAO’s analysis of EPA, National Center for Food and Agricultural Policy, and USDA data. 

Although they do not all produce their toxic effects in the same way, 

pesticides in these three classes—organochlorines, organophosphates, 

and carbamates—act on the nervous system to prevent the normal flow of 

nerve impulses to muscles that control both voluntary movement, such as 

walking, and involuntary movement, such as breathing and heart beat. 

Pesticides in all three classes are absorbed to varying degrees through 

inhalation, ingestion, and skin contact. Exposure to amounts of these 

pesticides that exceed levels set by EPA could result in immediate and lifethreatening effects, such as respiratory failure, or conditions that do not 

appear immediately, such as cancer. While EPA has concluded that most 

of these 17 pesticides do not cause birth defects, the agency has also 

concluded that 5 of them and a by-product of another may cause cancer.12

Since the 1970s, EPA has severely restricted its approvals of 

organochlorine pesticides, which include DDT, aldrin, and chlordane, 

because of their potential to harm humans and the environment. 

Organochlorine pesticides persist in the environment—some have 

remained in soil for over 50 years—and accumulate in body tissue, 

particularly fat. Organochlorine pesticides are associated with a range of 

adverse health effects, including cancer and damage to the neurological 

and reproductive systems. The one organochlorine pesticide still approved 

for use on tobacco, endosulfan, is highly toxic when ingested or inhaled 

and slightly toxic through contact with the skin. While EPA has 

determined that it is unlikely to cause cancer as other members of this 

class do, endosulfan, like all organochlorine pesticides, primarily affects 

the nervous system. EPA has requested additional data from the 

manufacturer to address its concerns that exposure to endosulfan could 

 12EPA will assess the health effects of carbofuran in fiscal year 2003 during its 

reregistration review. 
Page 12 GAO-03-485 Pesticides on Tobacco 

harm the nervous system of developing fetuses. Organophosphate and 

carbamate pesticides have largely replaced the organochlorine pesticides 

in the United States. 

While they break down quickly in the environment and do not accumulate 

in body tissues, organophosphate pesticides are much more acutely toxic 

to humans and animals than the persistent organochlorine pesticides they 

have largely replaced. The primary cause of death from organophosphate 

poisoning is respiratory failure, although cardiovascular symptoms, such 

as decreased heart rate that progresses to cardiac arrest, usually occur as 

well. In humans, additional symptoms from exposure to organophosphate 

pesticides, which can develop during use or within minutes to hours after 

exposure, include headache, nausea, dizziness, sweating, muscle 

twitching, anxiety, and depression. Exposure by inhalation causes the 

most rapid appearance of toxic symptoms. As a result, to minimize the 

potential for harmful exposure of workers, EPA requires those who mix, 

use, or apply the pesticides to have special training, use respirators, and 

wear chemical-resistant clothing. Regarding the potential to cause cancer, 

EPA has determined that 4 of the 10 organophosphate pesticides used on 

tobacco—acephate, ethoprop, methidathion, and trichlorfon—may cause 

cancer. In addition, EPA has concluded that 7 of the 8 organophosphate 

pesticides it evaluated for their potential to cause birth defects would not 

cause them but that the eighth—chlorpyrifos—may do so at very high 

levels that may also harm the pregnant female.13

Carbamates, which also affect the central nervous system, produce 

symptoms similar to those of organophosphate pesticides, although the 

effects of carbamate poisoning tend to be of shorter duration and 

somewhat easier to treat. The primary cause of death from carbamate 

poisoning is respiratory failure. Of the six carbamate pesticides used on 

tobacco, EPA has determined that one and a by-product always associated 

with another may cause cancer; two are unlikely to cause cancer; data are 

insufficient to determine the cancer-causing potential of one; and one will 

be evaluated in fiscal year 2003. EPA has evaluated four of the carbamates 

for their potential to cause birth defects: three do not and only minimal 

evidence exists for the potential of the fourth to cause birth defects. EPA 

has requested, but not yet received, data from the manufacturer on the 

 13EPA has requested data to assess the potential of trichlorfon, which is no longer approved 

for use on tobacco, to cause birth defects and has terminated its assessment of fonofos 

because all uses of the pesticide were cancelled. 
Page 13 GAO-03-485 Pesticides on Tobacco 

potential of one of the two remaining carbamate pesticides to produce 

birth defects, and the agency will evaluate the health effects of the other in 

fiscal year 2003. 

The potential acute adverse health effects from the remaining 20 

pesticides used on tobacco—representing 12 different chemical classes—

range from mild to severe.14 For example, EPA found no known health 

effects on mammals from exposure to Bacillus thuringiensis as it is 

currently manufactured. Similarly, EPA has found that both maleic 

hydrazide, a plant growth regulator and herbicide, and metalaxyl, a 

fungicide, have low acute toxicity, and neither is thought to cause cancer 

or birth defects. However, EPA has found that serious adverse health 

effects could occur with high exposures to insecticides, such as 

chloropicrin, 1,3-dichloropropene (1,3-D), and methyl bromide, which are 

applied as fumigants and can be severely irritating to the eyes, skin, and 

lungs. EPA has also found that poisoning from exposure to methyl 

bromide may result in persistent neurological impairment. 

In general, because most of the pesticides used on tobacco are widely 

used on food and other crops, as well as in residential and other settings, 

the exposure resulting from residues on tobacco represents a small 

portion of total exposure to these pesticides. Specifically, 1997 survey data 

estimate that about 27 million pounds of the 37 pesticides were used on 

tobacco, while the estimated use of these pesticides nationally on all crops 

was 175 million pounds. Therefore, most of the exposure to these 

pesticides stems from their use on other crops and in other products, such 

as household insecticides. However, for some pesticides—dimethomorph, 

fenamiphos, flumetralin, maleic hydrazide, mefenoxam, and 

sulfentrazone—more than 50 percent of their use in 1994 through 1998 was 

on tobacco. Further, more than 80 percent of maleic hydrazide used and 

100 percent of flumetralin and sulfentrazone used were applied to tobacco. 

Appendix II provides information on the amounts of the 37 pesticides used 

on (1) tobacco and (2) domestic crops, as estimated in the 1992 and 1997 

surveys. 

 14One herbicide, clomazone, has not been classified chemically. 
Page 14 GAO-03-485 Pesticides on Tobacco 

To determine whether the use of individual pesticides can reasonably be 

expected not to harm human health, EPA conducts health risk 

assessments under its pesticide registration program. These risk 

assessments are based on EPA’s evaluations of the results of numerous 

scientific studies and tests that the agency requires pesticide 

manufacturers to carry out. EPA also assesses the health risks to smokers 

from exposure to pesticides used on tobacco by analyzing data on their 

toxicity and the residue levels that remain on tobacco and in tobacco 

smoke. Because pesticides are used extensively on crops, including 

tobacco, and in home pesticide products, the risk assessments focus on 

exposures of (1) workers who handle the pesticides and (2) the general 

public, which is exposed to pesticides via residues on food or in drinking 

water or from pesticide products used in and around the home and in 

public places. EPA’s health risk assessments often identify risks to 

workers that must be mitigated before EPA will approve the pesticide. The 

assessments also identify risks to the general population that may also 

require special limitations on how or where the pesticides may be used. 

EPA has generally concluded that the low levels of residues measured in 

tobacco smoke do not pose health concerns that require mitigation. While 

EPA officials were generally able to provide us with copies of the studies 

and evaluations we requested during our review, documentation of the 

agency’s evaluation of the validity and reliability of the residue studies was 

inconsistently available. 

Under its pesticide registration program, EPA routinely assesses the health 

risks of exposure to pesticides from residues in drinking water and food 

and from pesticide use in the home, in public places, and at work. The 

Health Effects Division of the Office of Pesticide Programs in EPA 

develops its health risk assessments on the basis of a substantial body of 

data, including toxicity, residue chemistry, and other data provided by 

pesticide manufacturers, as well as other relevant information, such as 

human and animal studies from the general scientific literature and 

poisoning incident databases. The risk assessments focus on the potential 

cancer and noncancer health risks associated with short-term (acute), 

intermediate-, and long-term (chronic) exposures to pesticides from the 

primary exposure routes—oral, inhalation, and contact with skin (dermal). 

Noncancer health risks that EPA assesses include risk of birth defects, 

reproductive impairments, damage to genetic material, and interference 

EPA Concludes that 

Health Risks of 

Pesticide Residues on 

Tobacco Are Minimal 

but Requires 

Mitigation for Risks 

from Other Exposures 

EPA Assesses Health Risks 

of Varied Exposures to 

Pesticides 
Page 15 GAO-03-485 Pesticides on Tobacco 

with the body’s endocrine system.15 EPA’s health risk assessments are 

subject to numerous reviews by a variety of committees, including the 

agency’s Hazard Identification Science Assessment Review Committee, 

Cancer Science Assessment Review Committee, and Reproductive and 

Developmental Toxicity Science Assessment Review Committee. The 

health risk assessments provide critical information to the pesticide 

registration divisions on the human health component of risk management 

decisions—such as whether to approve pesticides for use; what amounts 

may be used; and what special restrictions, if any, may be needed. 

To evaluate the levels of pesticides to which cigarette smokers might be 

exposed from residues on tobacco, EPA reviews plant metabolism and 

residue studies provided by manufacturers that identify the residues of 

pesticides, and any harmful by-products16 they may produce, that remain 

on the crop after it has been treated. The plant metabolism studies reveal 

how plants process a pesticide once it is applied and the relative amounts 

of the pesticide and its by-products that remain after treatment—the total 

toxic residue (TTR). The residue studies, called field trials, quantify the 

levels of pesticide and by-product residues that remain on plants grown 

under actual agricultural conditions that approximate the expected “real 

life” environment. Such field trial data, which are required for all 

pesticides that will be used on food, may not always be required for 

pesticides used on tobacco because EPA uses a “tiered” approach to 

evaluate residues on tobacco. That is, for tobacco, the agency requires 

additional residue data after the metabolism study only if it has shown that 

the combined residue levels of the pesticide itself and any harmful 

by-products exceed 0.1 parts per million (ppm)—the agency’s “threshold 

of concern” for residues on tobacco. Thus, as figure 1 shows, EPA 

generally requires plant metabolism studies for green tobacco and may 

require data from field trials for both green and cured (aged) tobacco, 

 15The body’s endocrine system produces hormones that help guide the development, 

growth, reproduction, and behavior of animals, including humans. Some chemicals can 

interfere with the normal function of this complex system in ways that mimic a natural 

hormone, thereby fooling the body into overresponding to a hormone or blocking the 

effects of a hormone. Others may directly stimulate or inhibit the endocrine system, leading 

to overproduction or underproduction of hormones. Certain drugs are used to intentionally 

cause some of these effects, such as birth control pills. 

16EPA requires metabolism studies to identify by-products of pesticides that are of 

toxicological concern or that account for 10 percent or more of the total radioactive 

residues. (For metabolism studies, the pesticides have had radioactive atoms attached to 

their molecular structure to allow tracking of the pesticide through the plant.) 
Page 16 GAO-03-485 Pesticides on Tobacco 

depending upon the amount of residues that are identified.17 In addition, 

EPA may require pyrolysis studies that measure the residues in smoke 

when tobacco treated with a pesticide is burned. Finally, EPA may require 

additional residue studies to estimate potential exposure, even if the 

residues are below 0.1 ppm, if it has concerns about the toxicity of a 

pesticide. 

 17The results of metabolism studies on food crops may be used to determine the identity of 

the residues of concern. 
Page 17 GAO-03-485 Pesticides on Tobacco 

Figure 1: EPA’s Tiered Approach to Assessing Health Risks of Exposure to 

Residues on Tobacco 

a

Residues are measured as TTR—the sum of the residue from the parent pesticide and its 

by-products (degradation products, metabolites, and impurities that are of toxicological concern). 

b

Pyrolysis refers to chemical change brought about by the action of heat (burning). 
Page 18 GAO-03-485 Pesticides on Tobacco 

The tiered approach to analyzing residues on tobacco reflects the fact that, 

typically, pesticide residues on tobacco decline over time, as the tobacco 

is stored, cured, manufactured into cigarettes, and burned during 

smoking.18 EPA uses the tiered approach for tobacco, in part, because the 

agency has concluded that the potential for harm to human health from 

pesticide residues on tobacco at or below the 0.1-ppm level is extremely 

low and unlikely to result in a risk of concern to smokers.19

According to EPA officials in the Health Effects Division, since August 

1999, EPA’s policy for assessing the health risks from using pesticides on 

tobacco has been to evaluate the risks of short-term exposure to residues 

on tobacco and to quantify the estimated health risks using a consistent 

method and set of assumptions.20 This policy is applied to all newly 

registered pesticides, as well as to currently registered pesticides as they 

are periodically reviewed to ensure they meet current human health and 

environmental safety standards in accordance with the requirements of 

the 1988 amendments to FIFRA. EPA officials attribute the more 

structured approach to advances in the science of risk assessment and the 

1996 enactment of FQPA, which has spurred the agency to more 

systematically quantify the exposure to pesticide residues in food and 

drinking water and from residential uses. 

EPA selected the margin of exposure method to quantify the health risks 

associated with exposure to pesticide residues in smoke. As discussed 

earlier, a margin of exposure shows how far the actual (or estimated) 

human exposure to a substance is from levels that have been shown to 

 18EPA does not use the tiered approach to analyze pesticide residues on food and feed 

crops. Instead, it generally requires data on how the plants metabolize the pesticide and 

studies of residues that remain at the time of harvest (field trials), and, in some cases, as 

the food is processed. 

19EPA’s conclusion is based on its analysis, which compared its threshold (0.1 ppm) with 

residue levels at which inhalation exposure to other pesticide residues produces no 

harmful effects. Specifically, the 0.1-ppm threshold represents an estimated actual 

exposure to pesticide residues equivalent to half of the lowest residue level that EPA 

officials know of for inhalation exposure that does not produce adverse effects. 

20Prior to 1999, the determination of the methodology and assumptions for assessing the 

risk to smokers of pesticide residues on tobacco was left to the discretion of individual 

toxicologists, who made independent determinations for each chemical based on what they 

considered to be reasonable assumptions. Quantitative risk assessments generally were not 

performed. This new policy was formalized as guidance in August 2000 and is available 

electronically to EPA’s risk assessors as part of the Health Effects Division’s Risk Science 

Assessment Review Committee Library. 
Page 19 GAO-03-485 Pesticides on Tobacco 

cause no harm in animal studies. To estimate exposure, EPA typically uses 

(1) the residue levels identified in tobacco field trials or pyrolysis studies 

and (2) standard assumptions for key variables that affect exposure. 

Specifically, EPA assumes that people smoke 15 cigarettes a day21 and that 

they weigh about 150 pounds, if male, and 130 pounds, if female. 

Moreover, EPA assumes 100 percent of the pesticide residue on the 

tobacco is inhaled and absorbed. In practice, some residues will be 

trapped in cigarette butts, and the amount of smoke inhaled varies widely 

among people. EPA officials said the assumptions are conservative—that 

is, they are protective of public health—because they tend to overstate, 

rather than understate, the extent to which smokers are exposed to the 

potentially toxic effects of the pesticides. 

Also according to EPA officials, the agency does not include exposure to 

the residues in tobacco smoke in its aggregate health risk assessments of 

individual pesticides, which are required by FQPA, because the added 

exposure from residues in smoke is minimal. In addition, EPA has chosen 

not to assess the risk of either intermediate- or long-term exposure to 

pesticide residues in smoke because of the severity and quantity of health 

effects associated with the use of tobacco products themselves. 

Specifically, exposure to tobacco products—particularly cigarettes—is the 

single major preventable cause of cancer and heart and lung disease in the 

United States. 

Finally, although experts and public health officials are concerned about 

the potential for harm, particularly to children, from exposure to 

pesticides, little is known directly about the chronic effects of pesticide 

use in general in the United States—for example, in agriculture and in 

schools.22 Moreover, studies linking adverse human health effects to 

exposure to pesticide residues on tobacco are rare, according to public 

health officials and experts we spoke to. And while a number of federally 

sponsored studies of the effects of exposure to pesticides are underway, it 

will be years, if not decades, before conclusive results are known. Officials 

and experts we spoke with about possible harm from pesticide residues on 

 21Pierce, J.P., et al., 1989. Tobacco Use in 1986 – Methods and Basic Tabulations from 

Adult Use of Tobacco Survey. U.S. Department of Health and Human Services Publication 

Number OM90-2004. Office on Smoking and Health, Rockville, Maryland. 

22U.S. General Accounting Office, Pesticides: Improvements Needed to Ensure the Safety 

of Farmworkers and Their Children, GAO/RCED-00-40 (Washington, D.C.: Mar. 14, 2000) 

and Pesticides: Use, Effects, and Alternatives to Pesticides in Schools, GAO/RCED-00-17

(Washington, D.C.: Nov. 29, 1999). 
Page 20 GAO-03-485 Pesticides on Tobacco 

tobacco generally agreed that such residues could incrementally add to 

the risk, and some also believed the known harm from using tobacco 

products dwarfs any potential effect from exposure to pesticide residues 

in the smoke. 

EPA’s health risk assessments have identified a number of potential 

adverse health effects associated with the pesticides used on tobacco and 

other crops that, in some cases, have led the agency to impose special 

limitations on the uses of these pesticides. The risks that required 

mitigation stemmed from (1) potential exposure of workers who apply 

pesticides or harvest crops and (2) potential exposure of the general 

population to pesticide residues in food or drinking water or from 

pesticides used in the home or in public. None of the risks requiring 

mitigation were associated with exposure to residues on tobacco or in 

tobacco smoke. 

Our review of studies and other documentation related to EPA’s 

completed reregistration reviews of 13 of the 37 pesticides commonly used 

on tobacco identified the health risks associated with them and the related 

mitigation measures the agency required. 23 The following cases illustrate 

some of the health risks that have required mitigation. 

EPA has classified 1,3-D, a widely used fumigant that controls soil-borne 

pests and diseases, as a probable carcinogen—that is, evidence from 

human and animal studies suggests that 1,3-D, once ingested or inhaled, is 

likely to cause cancer. In its risk assessment, EPA determined that 1,3-D 

could make its way to groundwater and pose a risk of cancer for residents 

who obtained their drinking water from wells near treated fields. To 

mitigate the potential cancer risks and as a condition for reregistration, 

EPA required that wells used for drinking water be located 100 or more 

feet from treated fields and prohibited the use of 1,3-D altogether in 11 

states with porous soil.24 In addition, vapors from 1,3-D—which is injected 

as a liquid into soil, where it quickly evaporates—can move into the air. 

Consequently, EPA also required (1) a 300-foot buffer between occupied 

 23The 13 pesticides are 1,3-D, acephate, chlorpyrifos, diazinon, disulfoton, endosulfan, 

ethoprop, ethephon, maleic hydrazide, metalaxyl, methidathion, pebulate, and 

pendimethalin. 

24The 11 states where 1,3-D cannot be used are Maine, Massachusetts, Minnesota, Montana, 

New Hampshire, New York, North Dakota, South Dakota, Utah, Vermont, and Wisconsin. 

EPA Concludes That Risks 

Associated with Pesticide 

Use Can Be Significant, but 

Those Associated with 

Pesticide Residues on 

Tobacco Appear to Be 

Minimal 

Some of EPA’s Risk 

Assessments Result in Special 

Mitigation Measures 
Page 21 GAO-03-485 Pesticides on Tobacco 

buildings and fields treated with the pesticide and (2) workers who apply 

the pesticide to wear respirators and protective clothing, among other 

things. Further, because of 1,3-D’s volatility and potential to harm humans, 

EPA classified it as a “restricted use” pesticide, which means it can only be 

applied by, or under the supervision of, individuals trained to handle 

particularly toxic or harmful pesticides. Currently, 1,3-D is registered for 

use on soils in which all food and feed crops may be planted. Moreover, 

according to the 1997 survey, an estimated 13 million pounds of 1,3-D were 

applied to tobacco annually during the survey period—almost twice the 

amount of chloropicrin, the second most commonly used pesticide on 

tobacco.25 Despite the health risks posed by injecting 1,3-D into soil, EPA 

identified no risks associated with residues on tobacco leaves or in 

tobacco smoke because 1,3-D metabolizes to nontoxic by-products and is 

subsequently absorbed by the plant.26

Similarly, EPA determined that residues on tobacco of chlorpyrifos—

another pesticide frequently used on tobacco and food crops and one of 

the most widely used organophosphate insecticides in the United States—

were below the agency’s threshold of concern. But the agency determined 

that chlorpyrifos presented potential health risks unrelated to its use on 

tobacco that required strict mitigation measures. Specifically, the agency 

identified health risks to children from exposure to chlorpyrifos. Before 

2000, chlorpyrifos was one of the insecticides used most often in 

residential and commercial settings—for example, on carpets and in 

schools, daycare centers, hotels, and restaurants—and on food crops. EPA 

identified significant risks to children from these many uses and required 

stringent measures to address them. Between 1997 and 2000, EPA 

cancelled nearly all indoor and outdoor residential uses and prohibited the 

use of chlorpyrifos in schools and public parks. In addition, manufacturers 

agreed to eliminate the use of chlorpyrifos on tomatoes and restrict its use 

on apples.27 EPA also identified concerns for some workers who mix, load, 

 25The 1997 survey estimated that, of the 37 pesticides used on tobacco in the 1990s, 12 were 

applied to tobacco in amounts less than 100,000 pounds and 8 were shown as not used 

during this survey (1994-98). See appendix II for more detail on the estimated amounts of 

pesticides used on tobacco. 

26Although 1,3-D is also widely used on soils where food crops are planted, EPA does not 

require that food use tolerances be established for this pesticide because no residues 

remain on plants grown in treated soil. 

27Chlorpyrifos is currently registered to control foliage-borne and soil-borne pests on food 

and feed crops; at golf courses; and on nonstructural wood, such as utility poles and fence 

posts, as well as to kill adult mosquitoes. Structural treatments for termites are also 

registered uses but are being phased out by the end of 2005. 
Page 22 GAO-03-485 Pesticides on Tobacco 

and apply chlorpyrifos in agricultural and other nonresidential settings. As 

a result, EPA required that workers wear a respirator and a double layer of 

clothing, including chemical-resistant gloves, shoes, and headgear. 

Workers must also use water-soluble packages to mix powdered forms of 

chlorpyrifos and remain in an enclosed cockpit when aerially spraying a 

field. EPA also set a time interval between applications of the pesticide 

and when workers can reenter treated areas, ranging from 24 hours for 

most crops to 5 days for others. EPA did not, however, identify risks 

associated with chlorpyrifos used on tobacco because residue levels on 

green tobacco were below 0.1 ppm. 

EPA also identified a range of potential harmful effects from other 

exposures to the other pesticides we reviewed. For 11 pesticides, 

including 1,3-D and chlorpyrifos, EPA identified a range of concerns, 

largely for exposures of workers—particularly those engaged in spraying 

the pesticides—that required at least some mitigation. Most often the 

mitigation measures included the use of enclosed mixing systems and 

tractor cabs, additional protective respirators and clothing, reductions in 

the rate and frequency of application, and increases in the time between 

application and reentry to the treated areas. In some cases, such as for 

acephate, disulfoton, and ethoprop—all of which are organophosphate 

pesticides—certain uses were cancelled, including use on golf courses and 

lawns and indoor and outdoor residential uses. Three of these 11 

pesticides—disulfoton, endosulfan, and ethoprop—also raised concerns 

about dietary or drinking water exposure for which EPA required such 

mitigation as canceling use on some foods, reducing the rate and 

frequency of application on others, and requiring buffer zones between 

treated fields and water bodies. EPA placed a number of additional 

restrictions on the use of endosulfan, a highly toxic and persistent 

organochlorine pesticide, including restricting use on cotton and tobacco 

to certain states; eliminating or reducing aerial spray applications on crops 

such as strawberries, nuts, and tobacco; and requiring buffer zones 

between treated areas and bodies of water.28 In addition, EPA required that 

all products containing endosulfan be labeled as restricted use pesticides, 

which can only be used by, or under the supervision of, specially trained 

 28EPA determined that endosulfan can be used on tobacco in only 6 of the 16 states where 

it is grown—Indiana, Kentucky, Ohio, Pennsylvania, Tennessee, and West Virginia—which 

account for about 40 percent of domestic production. 
Page 23 GAO-03-485 Pesticides on Tobacco 

applicators.29 EPA also noted that it may require further restrictions on 

acephate once the agency completes its assessment of the cumulative 

exposure to organophosphate pesticides because this organophosphate 

pesticide degrades in plants to another organophosphate pesticide.30 EPA 

found that 2 of the 13 pesticides we reviewed presented no concerns that 

needed changes in existing conditions on how to use and apply the 

pesticides.31

The pesticides we reviewed, including ones no longer approved for use in 

the United States, are used in many other tobacco-producing countries, 

according to experts. Researchers and advocacy groups have raised 

concerns about adverse health effects on tobacco workers in other 

countries from exposure to pesticides, citing such factors as the absence 

of cautionary labels on some pesticides and the limited use of protective 

clothing by agricultural workers. For example, researchers found elevated 

rates of depression and suicide rates that were twice the national average 

among tobacco producers in Brazil, a leading tobacco exporter. And 

although many factors, such as poverty and stress, may play a role in 

suicide, one group of researchers noted tobacco producers in Brazil 

routinely used organophosphate pesticides, which have been shown to 

cause depression. Moreover, these researchers reported that suicides are 

more likely to occur during planting and harvesting seasons, when 

organophosphate pesticides are used intensively. To some extent, such 

harmful exposure may occur because pesticide regulations in other 

countries may be less stringent than those in the United States or because 

other countries’ enforcement of regulations may be more limited, 

according to advocacy groups. 

Regarding pesticide residues on domestic tobacco, overall, EPA officials 

did not find associated health risks that required mitigation. Further, the 

data we reviewed on 13 pesticides were consistent with statements from 

EPA officials that the residues on tobacco were below the agency’s 

 29Of the 13 pesticides we reviewed, all of the currently approved products containing 1,3-D, 

disulfoton, and ethoprop are restricted use products, and some of the products containing 

chlorpyrifos are restricted use products. 

30In June 2002, EPA issued a preliminary cumulative risk assessment for organophosphates 

for public comment. The agency, in consultation with scientific advisors, will revise the 

assessment on the basis of comments and data that were submitted. No date has been set 

to issue the final cumulative risk assessment for organophosphate pesticides. 

31Maleic hydrazide and metalaxyl. 
Page 24 GAO-03-485 Pesticides on Tobacco 

identified level of concern in 11 cases. EPA did not evaluate the remaining 

2 pesticides—diazinon and pendimethalin—for use on tobacco. In the case 

of diazinon, evaluating residue data was not relevant because the pesticide 

was no longer approved for use on tobacco at the time EPA conducted its 

evaluation. In the case of pendimethalin, at the time we conducted this 

work, EPA had not yet reviewed the relevant data received from the 

manufacturer. EPA approved the reregistration for this pesticide, but its 

use on tobacco is subject to the agency’s evaluation of this data. 

Of the 11 pesticides that EPA evaluated for use on tobacco, 3 left residues 

on green or cured tobacco that were less than 0.1 ppm—and one left no 

residues at all. Specifically, the maximum residues of ethoprop on green 

tobacco were 0.01 ppm, the residues of chlorpyrifos were 0.09 ppm, the 

residues of pebulate on both green and cured tobacco were less than 

0.02 ppm, and the plant metabolism study for 1,3-D showed no residues 

remaining on the plant. Manufacturers provided pyrolysis studies in two of 

the four cases in which the residue levels on green tobacco were 0.1 ppm 

or less. The pyrolysis study for ethoprop identified residues in the smoke 

that were below the agency’s level of concern. The pyrolysis study for a 

by-product of chlorpyrifos that was initially of concern to the agency 

identified the by-product in the smoke. However, EPA subsequently 

concluded that the by-product, which accounted for more than 10 percent 

of the residue in the smoke, was not of toxicological concern because, 

unlike its parent compound, it does not act toxically on the nervous 

system. 

Of the seven pesticides that progressed through EPA’s tiered risk 

assessment approach because residues on cured tobacco were greater 

than 0.1 ppm, pyrolysis studies were conducted on five. No residues were 

found in the smoke of four of these five pesticides; the residues of the fifth 

were not of sufficient magnitude to require further study or evaluation. 

One of the remaining two pesticides with residue levels greater than 

0.1 ppm was evaluated using a study of the health effects on rats exposed 

to residues in smoke,32 and one was approved subject to EPA’s review of 

requested additional residue data, including a pyrolysis study, to confirm 

EPA’s assessment that residues on tobacco do not pose a risk to human 

health. 

 32EPA issued the reregistration decision for this pesticide, metalaxyl, in 1994. EPA officials 

said they would no longer substitute a rat inhalation study for a pyrolysis study. 

Researchers found no difference between rats exposed to smoke containing metalaxyl 

residues and those that were not. 
Page 25 GAO-03-485 Pesticides on Tobacco 

The reregistration decisions for 7 of the 13 pesticides we reviewed were 

issued after EPA implemented guidance in 1999 requiring quantification of 

the risks of short-term exposure to pesticide residues in tobacco smoke.33

However, none of the human health risk assessments or other 

documentation we reviewed contained this information—that is, the 

margin of exposure estimate—because the health risk assessments 

supporting these decisions were completed before the policy was 

implemented. For pesticides with many uses and much data, several years 

may elapse between the initial scientific assessment of the tobacco use 

and the issuance of the reregistration decision. 

Not including the 13 pesticides mentioned above, we reviewed five 

additional health risk assessments EPA prepared after it developed the 

policy requiring the quantification of the risks of short-term exposure to 

pesticide residues in tobacco smoke that did include estimates of margin 

of exposure. EPA generally does not have concerns about adverse health 

effects when a margin of exposure is greater than 100—that is, when the 

pesticide causes no adverse effects at levels 100 or more times greater 

than the expected actual exposure to the pesticide. Consequently, a 

margin of exposure greater than 100 is considered to reflect risk that is 

below EPA’s level of concern. As table 4 shows, EPA’s recent health risk 

assessments of five pesticides approved for use on tobacco—four of which 

were newly registered and one reregistered—generally indicated that the 

margins of exposure were substantially greater than 100. Although one 

margin of exposure was below 100, EPA officials told us that because they 

used very conservative assumptions to estimate exposure, resulting in an 

extreme overstatement of actual exposure, EPA was not concerned about 

the potential for adverse health effects. For these five pesticides, EPA 

concluded that no mitigation related to the use on tobacco was required. 

Overall, EPA officials said that potential risks from exposure to residues 

on tobacco had never been high enough to require mitigation. 

 33The other 6 registration decisions were issued prior to the 1999 guidance. 
Page 26 GAO-03-485 Pesticides on Tobacco 

Table 4: Margins of Exposure for Five Pesticides Approved for Use on Tobacco 

Pesticide 

Margin of exposure

(male)

Margin of exposure

(female)

Actigard 518,518 444,444

Carbaryl 104 89

Dimethomorph 1,400 1,200

Pymetrozine 3,333 2,857

Thiamethoxam 3,500 3,000

Source: GAO and EPA. 

Note: GAO’s analysis of EPA risk assessment documents. 

EPA requires that pesticide manufacturers provide most of the studies it 

considers in assessing the health risks of pesticides, and the agency’s 

evaluations of these studies are critical to the assessment process. EPA 

officials were generally able to provide us with copies of the studies and 

evaluations we requested, but documentation of the agency’s evaluation of 

the quality of the residue studies and other data upon which it relied to 

evaluate the potential for adverse health effects was inconsistent. 

Specifically, for eight of the pesticides, EPA officials were unable to 

provide their evaluations of the validity and reliability of residue data used 

in their assessments of potential health risks. In addition, for chlorpyrifos, 

EPA officials were unable to provide the residue studies and agency 

evaluations of them from the early 1980s. As a result, we examined 

subsequent EPA evaluations that referred to the results of these early 

studies and the agency’s conclusion that the residues were below the level 

of concern. According to EPA officials, they were unable to locate the 

documents, in part, because not all records from this time have yet been 

converted to electronic format, and the paper copies could not be located 

among the substantial backlog of paper documents. EPA officials noted 

that each pesticide registration could consist of 100 or more studies from 

pesticide manufacturers, each of which requires one or more agency 

evaluations. The officials reported that, as resources permit, contract and 

agency staff are converting documents to electronic format to make them 

more readily available for review. 

While EPA is required to regulate residues of pesticides approved for use 

on human food and animal feed crops, no such requirement applies to 

pesticides approved for use on tobacco. However, primarily as a matter of 

trade equity, USDA does (1) regulate residues of selected pesticides that 

are prohibited in the United States but that may be used on imported 

tobacco and (2) test certain types of imported and domestic tobacco to 

EPA Evaluations of Studies Are 

Not Always Available 

Federal Regulation of 

Pesticide Residues on 

Tobacco Is Limited 
Page 27 GAO-03-485 Pesticides on Tobacco 

ensure they do not exceed residue limits. USDA has not reevaluated the 

pesticides it regulates since 1989, although changes in the pesticides used 

on tobacco have occurred since then. Through its testing programs, USDA 

has found that a small fraction of imported and domestic tobacco exceeds 

the residue limits. 

As discussed previously, EPA regulates pesticides in the United States by 

granting registrations, which permit the distribution, sale, and use of the 

pesticides according to directions identified on the label. EPA also 

regulates the residues of pesticides that are approved for use on human 

food and animal feed crops by setting tolerances—maximum 

concentrations of residues that may remain on crops. FDA and USDA test 

food and feed crops to ensure that residue levels do not exceed the 

tolerances EPA has set. Because tobacco is not used as food or feed, 

however, EPA does not set tolerances for residues of pesticides approved 

for use on tobacco,34 and FDA and USDA do not test tobacco for maximum 

concentrations of residues of approved pesticides. Consequently, residues 

of pesticides approved for use on tobacco in the United States are not 

federally regulated. 

Instead, federal regulation of pesticide residues on tobacco focuses 

exclusively on pesticides not approved for use on tobacco. The Dairy and 

Tobacco Adjustment Act of 1983, as amended, requires USDA to 

(1) establish maximum allowable concentrations for residues of selected 

pesticides that are not approved for use on tobacco in the United States 

but that are likely used on tobacco in some other countries and (2) test 

imported and domestic flue-cured and burley tobacco to ensure the 

residue levels do not exceed the maximum levels allowed.35 In selecting 

which pesticide residues to regulate, USDA is to consider pesticides 

whose use on tobacco has been cancelled, suspended, revoked, or 

otherwise prohibited under FIFRA. The regulation helps ensure that 

domestic tobacco producers are not placed at an unfair disadvantage in 

the market because they are not allowed to use certain pesticides that may 

 34In addition, EPA does not require validation by an independent laboratory of the analytic 

method used to measure pesticide residues on nonfood crops as it does for methods used 

to measure pesticide residues on food and feed. The purpose of the external validation is to 

support enforcement of tolerances by ensuring that competent analysts can apply the 

method used. 

357 U.S.C. 511r. 

Federal Regulation 

Focuses on Pesticides Not 

Approved for Use on 

Tobacco 
Page 28 GAO-03-485 Pesticides on Tobacco 

be used in other countries; it also helps protect the public from exposure 

to the residues of highly toxic pesticides not approved for use on tobacco 

in the United States. 

While the focus of U.S. regulation of pesticide residues on tobacco is on 

those pesticides not approved for use on tobacco, some other countries 

have set limits on residues of pesticides that are used on tobacco. Further, 

as in the United States, some countries limit the concentration of residues 

as measured on tobacco leaf. However, at least one country—Germany—

limits the pesticide residues as measured in cigarettes and other tobacco 

products. Appendix III provides information on the limits established by 

Germany, Italy, and Spain. 

USDA has implemented the Dairy and Tobacco Adjustment Act, in part, by 

setting 15 residue limits (maximum allowable concentrations) covering 20 

pesticides currently not approved for use on tobacco in the United States 

that the agency believed were used in other countries. Most of the 

pesticides USDA regulates, such as DDT and toxaphene, are 

organochlorine pesticides. As discussed earlier, organochlorine pesticides 

persist in the environment and accumulate in the bodies of humans and 

animals, and many are highly toxic—a number of them have been banned 

for these reasons. Eleven of the 15 residue limits apply to individual 

pesticides and 4 apply to 2 or more pesticides in combination.36 For 

example, aldrin and dieldrin are summed because dieldrin is the primary 

degradation product of aldrin. Table 5 lists the residue limits included in 

USDA’s testing program, with the 12 organochlorine pesticides 

highlighted. As indicated in the table, methoxychlor is the only 

organochlorine pesticide included in USDA’s testing program that is 

currently approved for other uses in the United States, such as on food 

crops. 

 36USDA’s method of measuring residues is consistent with EPA’s and FDA’s. 

USDA Has Not 

Reevaluated the Pesticides 

it Regulates Since 1989 
Page 29 GAO-03-485 Pesticides on Tobacco 

Table 5: USDA’s Residue Limits for Pesticides on Tobacco 

Pesticide 

(organochlorine pesticides in bold) 

Residue limit 

(parts per 

million) 

Approved for 

nontobacco 

use(s)

1. Chlordane 3.0 No

2. Dibromochloropropane (DBCP) 1.0 No

3. Dicamba 5.0 Yes

4. Endrin 0.1 No

5. Ethylene dibromide (EDB) 0.1 No

6. Formothion 0.5 No

7. Hexachlorobenzene (HCB) 0.1 No

8. Methoxychlor 0.1 Yes

9. Toxaphene 0.3 No

10. 2,4-D 5.0 Yes

11. 2,4,5-T 0.1 Yes

12. Sum of aldrin and dieldrin 0.1 No

13. Sum of cypermethrin and permethrin 3.0 Yes

14. Sum of DDT, TDE, and DDE 0.4 No

15. Sum of heptachlor and heptachlor epoxide 0.1 No

Source: 7 CFR 29.427, USDA, and EPA. 

Note: GAO’s analysis of EPA data. 

USDA’s Agricultural Marketing Service (AMS) initially established 

maximum allowable concentrations of pesticides in August 1986 after 

determining the countries from which the United States imports tobacco, 

the pesticides that might reasonably be expected to be used on tobacco in 

those countries, and the pesticides not approved for use in the United 

States. In 1989, AMS revised the number of pesticides to its current total of 

20 residues. 

Although in 1986 USDA stated its intent to periodically reevaluate the 

pesticides it regulates, the department has not done so since 1989. 

According to officials at USDA, reevaluating the regulated pesticide 

residues has not been a priority of the department. However, since USDA 

selected the pesticides it would test in 1989, tobacco uses have been 

cancelled for more than 30 pesticides that had been approved for use on 

tobacco.37 For example, by 2000, EPA had cancelled all tobacco uses of 

lindane—a highly persistent, organochlorine pesticide that may cause 

 37Not including the cancelled pesticides, about 100 pesticides had approval for tobacco 

uses in the 1990s. 
Page 30 GAO-03-485 Pesticides on Tobacco 

cancer and harm the environment. USDA does not currently regulate 

pesticide residues of lindane because it was still approved for tobacco 

when USDA last reevaluated the regulated pesticides. Other pesticides, 

such as trichlorfon and diazinon, are also candidates for regulation—that 

is, pesticides no longer approved for use on tobacco in the United States 

but likely to be used in some other countries. As appendix III shows, some 

countries that set limits for pesticides used on tobacco have established 

them for trichlorfon and diazinon—one of the leading causes of acute 

insecticide poisoning for humans. However, because USDA has not 

revised the regulated pesticide residues it tests for, the department’s 

testing program may not include some pesticides with characteristics 

similar to those of pesticides currently included in the testing program and 

that may still be used in other countries. Tobacco and pesticide experts 

with whom we spoke agreed that periodic reevaluations of the regulated 

pesticides would be appropriate. Furthermore, two of these experts—a 

toxicologist who has measured residues on tobacco for many years and a 

former government official who now represents tobacco producers—told 

us that many of the pesticides USDA currently regulates, particularly the 

organochlorine pesticides, warrant continued inclusion in the testing 

program because they are persistent in the environment, accumulate in the 

body, and continue to be used on crops overseas. 

Also as required by the Dairy and Tobacco Adjustment Act, USDA tests 

certain imported and domestic tobacco to ensure that residues do not 

exceed the maximum allowable concentrations the agency established. 

USDA is required to test samples of two types of tobacco—flue-cured and 

burley—that are commonly imported from other countries and also 

produced in the United States to determine whether they conform to the 

pesticide residue limits. These two types of tobacco are the major 

components of cigarettes, and imports of them have continued to increase 

over time. For example, USDA reported that imports of flue-cured tobacco 

represented about 12 percent of the flue-cured tobacco used in the United 

States in 1980 and about 36 percent in 2001.38 USDA is not required to test 

other types of imported tobacco, such as oriental tobacco, which is added 

to cigarettes for purposes of flavor and aroma but which is not grown in 

the United States. 

 38USDA Economic Research Service U.S. Tobacco Import Update (TBS-2002-02), Feb. 2003. 

USDA Tests Imported and 

Domestic Tobacco for 

Regulated Pesticides 
Page 31 GAO-03-485 Pesticides on Tobacco 

Tobacco is imported into the United States in large, sealed shipping 

containers that hold approximately 40,000 pounds of tobacco in 90 to 96 

boxes weighing about 440 pounds each. In 1986, AMS began testing 

imported flue-cured and burley tobacco, which represented about 

60 percent of the tobacco imported into the United States in 2001. Random 

samples of imported flue-cured and burley tobacco are tested for residues 

of the 20 regulated pesticides. AMS inspectors use a computer program to 

randomly select one box of tobacco from each shipping container. The 

domestic testing program began in 1989 and is administered by the USDA 

Farm Service Agency (FSA)39 under a cooperative agreement with AMS. 

Similar to the AMS program for tobacco imports, FSA tests randomly 

selected samples of domestic flue-cured and burley tobacco for the 20 

regulated pesticides not approved for use in the United States. FSA tests 

the portion of domestically grown flue-cured and burley tobacco that 

becomes loan stock (surplus tobacco) under USDA’s tobacco price 

support program.40 The proportion of domestic tobacco that becomes loan 

stock varies each year, depending on tobacco quality and demand from 

manufacturers, and has declined in recent years. Additional information 

about the domestic loan stock program is provided in appendix IV. 

For 1999 through 2001, USDA’s testing programs found less than 1 percent 

of domestically produced or imported flue-cured and burley tobacco with 

residue levels above the allowable levels.41 According to agency officials, 

those results are consistent with results obtained since testing began in 

1986. More specifically, for 1999 through 2001, the FSA domestic testing 

program found a small fraction of a percentage of domestically produced 

tobacco in excess of the limits. FSA found 4 samples of flue-cured tobacco 

and 24 samples of burley tobacco—representing more than 12,000 pounds 

of tobacco—that exceeded the maximum allowable concentrations of 2 of 

the regulated pesticides—methoxychlor and permethrin. AMS found 

residues of DDT/TDE/DDE, cypermethrin, and ethylene dibromide in 

excess of the limits on less than 1 percent of the imported tobacco 

entering the United States during this time. 

 39FSA was formed in 1994 from programs in several agencies, including tobacco programs 

from the former Agricultural Stabilization and Conservation Service. 

40The price support program is administered by stabilization cooperatives—owned by 

tobacco growers—under agreement with USDA’s Commodity Credit Corporation and 

auction warehouses. 

41Imported tobacco percentage calculated by weight of imported flue-cured and burley 

tobacco; domestic percentage calculated by weight of flue-cured and burley loan stock. 
Page 32 GAO-03-485 Pesticides on Tobacco 

If imported tobacco exceeds any of the limits, the importer is notified of 

the violation and may choose to appeal the result or reexport the tobacco 

to another country. When an importer appeals, AMS inspectors randomly 

select three additional samples for testing, and the residue levels for the 

four samples are averaged. If the average result is below the limits, the 

tobacco is cleared for entry into the United States. However, if the average 

exceeds the limits, the container of tobacco is denied entry and is typically 

reexported. Under the Dairy and Tobacco Adjustment Act, domestically 

produced flue-cured or burley tobacco not meeting the residue 

requirements must be destroyed. According to USDA officials, because of 

restrictions on the disposition of products contaminated by pesticides, 

boxes of domestic tobacco are typically disposed of in an approved landfill 

with a permit from EPA. 

To ensure that pesticides can be used without posing an unreasonable risk 

to human health, EPA conducts risk assessments of exposures to the 

pesticides it evaluates for use in the United States, including exposure to 

pesticide residues on tobacco. EPA’s decision to limit its quantitative 

assessment of the risks associated with pesticides on tobacco to the 

effects of short-term exposure, and not include the long-term exposure of 

smokers, recognizes that the pesticides are used on a crop that itself poses 

very significant health risks to humans through use in various consumer 

products—primarily cigarettes. Overall, EPA’s health risk assessments 

show that the pesticides used on tobacco and other crops are probably a 

greater hazard for those who handle them than for those who inhale 

tobacco smoke. Nonetheless, while the risks of some exposures, such as 

acute poisoning, are clear, less is known with certainty about the effects of 

long-term exposure to small amounts of pesticides, such as residues in 

food and water, on tobacco, or in the environment. 

While historically EPA has required pesticide manufacturers to provide 

data on the residues remaining on tobacco, its assessments of the health 

effects associated with exposure to the residues were not identified in risk 

assessment documents and generally were not quantified. Mirroring the 

improvements in risk assessment methods in recent years, EPA has 

adopted a more formal and consistent approach to evaluating the health 

risks associated with pesticides used on tobacco and has started to 

document, in its risk assessment documents, its conclusions on the 

potential for short-term risks from pesticide residues that may remain in 

tobacco smoke. As a result, interested parties are better informed about 

the potential risks, and EPA is appropriately more accountable for its 

assessments. 

Conclusions 
Page 33 GAO-03-485 Pesticides on Tobacco 

When used as intended—most commonly in cigarettes—tobacco is 

generally inhaled into the body. However, because it is not a food, tobacco 

is regulated as a nonfood crop with regard to pesticide residues. That is, 

no residue limits are established or monitored for pesticides approved for 

use on tobacco, as is done for foods. While the regulation of pesticide 

residues on tobacco is limited because it does not include pesticides 

approved for use on this crop, USDA tests tobacco for residues of 20 

pesticides not approved for domestic use on tobacco, primarily for 

purposes of trade equity. Because many of the tested pesticides are known 

to harm humans and the environment, the USDA testing program helps 

minimize the public’s exposure to some highly toxic pesticides. The 

universe of pesticides not approved for use on tobacco has grown since 

USDA selected the pesticides it tests, but USDA has not reevaluated the 

program’s coverage in 14 years. The USDA testing program would be 

improved by assessing the current universe of pesticides not approved for 

use on tobacco and determining whether an update to its program is 

warranted. 

To better protect the public from exposures to residues of pesticides not 

approved for use on tobacco in the United States and ensure that domestic 

tobacco producers are not placed at an unfair disadvantage relative to 

producers in other countries, we recommend that the Secretary of the 

Department of Agriculture direct the Administrators of the Agricultural 

Marketing Service and the Farm Service Agency to periodically review and 

update the pesticides for which they set residue limits and test imported 

and domestic tobacco. 

We provided copies of our draft report to EPA and USDA for review and 

comment. In commenting on the draft, EPA officials said we accurately 

characterized the agency’s risk assessment process for pesticides used on 

tobacco, and USDA officials agreed with our recommendation to 

periodically review and update the pesticides for which the department 

sets residue limits and tests tobacco. USDA officials said they plan to 

annually review and update the testing program for tobacco. 

We conducted our review from May 2002 through March 2003 in 

accordance with generally accepted government auditing standards. Our 

scope and methodology are discussed in appendix I. 

Recommendation for 

Executive Action 

Agency Comments 
Page 34 GAO-03-485 Pesticides on Tobacco 

As agreed with your office, unless you publicly announce the contents of 

this report earlier, we plan no further distribution until 30 days from the 

report date. At that time we will send copies of this report to the 

Administrator, EPA; the Secretary of Agriculture; and other interested 

parties. We will make copies available to others upon request. In addition, 

the report will be available at no charge on GAO’s Web site at 

http://www.gao.gov. 

If you or your staff have any questions, please call me at (202) 512-3841. 

Key contributors to this report are listed in appendix V. 

Sincerely yours, 

John B. Stephenson 

Director, Natural Resources and Environment 
Appendix I: Objectives, Scope, and 

Methodology 

Page 35 GAO-03-485 Pesticides on Tobacco 

This report provides information on (1) the pesticides commonly used on 

tobacco and the potential health risks associated with them; (2) how the 

Environmental Protection Agency (EPA) assesses and mitigates health 

risks associated with pesticides used on tobacco; and (3) how, and the 

extent to which, EPA, U.S. Department of Agriculture (USDA), and other 

federal agencies regulate and monitor pesticide residues on tobacco. In 

addition, this report provides information on the regulatory residue limits 

adopted by three countries that are significant importers of tobacco grown 

in the United States. 

To identify the chemicals commonly used on tobacco, we reviewed 

pesticide-use databases developed by the National Center for Food and 

Agricultural Policy (NCFAP), a nonprofit research organization, under a 

cooperative agreement with USDA. These databases summarized national 

use of 235 pesticides on 87 food and nonfood crops for the period 1990 

though 1998. These databases, compiled from more than 130 federal and 

state surveys and reports, include pesticide use on cropland in the 

coterminous 48 states and do not include new pesticides approved by EPA 

since 1997. We also reviewed data from national surveys conducted in the 

1990s by the U.S. Geological Survey and USDA and from several tobaccoproducing states—Kentucky, North Carolina, Tennessee, and Virginia. In 

total, 53 pesticides were identified as being used on tobacco in one or 

more of the surveys. Of these, 37 were identified in one or more of the 

surveys that included national data, and we refer to this latter group as the 

pesticides that were commonly used on tobacco in the United States 

during the 1990s. To identify the adverse health effects associated with 

these 37 pesticides, we collected and reviewed relevant human health risk 

assessments prepared by EPA’s Office of Pesticide Programs. Where such 

assessments were not available, we reviewed documents from academic 

experts who maintain a database on pesticides and other toxic chemicals 

for USDA, and other programs within EPA. In addition we interviewed, 

and reviewed reports prepared or recommended by, experts on the human 

health effects of exposure to pesticides and other toxins at the National 

Cancer Institute, the National Institute of Environmental Health Sciences, 

the National Center for Environmental Health, Johns Hopkins Bloomberg 

School of Public Health, and the Institute for Cancer Prevention (formerly 

the American Health Foundation). 

To determine how EPA assesses and mitigates potential health risks from 

pesticide residues on tobacco, we reviewed agency policies and 

procedures on identifying the levels of pesticide residues on tobacco and 

the related health risks, and we interviewed EPA officials in the Office of 

Pesticide Programs who perform these tasks. In addition, we examined in 

Appendix I: Objectives, Scope, and 

Methodology 
Appendix I: Objectives, Scope, and 

Methodology 

Page 36 GAO-03-485 Pesticides on Tobacco 

detail how EPA implemented its policies and procedures for 13 of the 37 

pesticides commonly used on tobacco. That is, we reviewed pesticide 

residue studies submitted to EPA and EPA’s evaluations of pesticide 

residues and their potential health effects conducted as part of the 

pesticide registration process under the Federal Insecticide, Fungicide, 

and Rodenticide Act for 1,3-D, acephate, chlorpyrifos, diazinon, disulfoton, 

endosulfan, ethoprop, ethephon, maleic hydrazide, metalaxyl, 

methidathion, pebulate, and pendimethalin. We focused primarily on those 

pesticides for which EPA had completed registrations between 1994 and 

2002. We did not independently evaluate the validity or scientific merit of 

the studies that EPA relied upon to reach its conclusions. 

To determine the extent to which EPA, USDA, and other federal agencies 

regulate and monitor pesticide residues on tobacco, we met with 

cognizant officials and reviewed authorizing legislation, regulations, and 

documentation on how programs related to pesticide residues on tobacco 

are implemented. In addition, we analyzed USDA data on tobacco 

production, imports, and residue-testing results. We also interviewed 

academic and tobacco industry experts and reviewed residue data 

collected by North Carolina State University. 

To provide information on other countries that have adopted regulatory 

limits on pesticide residues, we reviewed articles by academic experts on 

the international regulation of pesticides on tobacco. We provide 

information on three major importers of U.S. tobacco—Germany, Italy, 

and Spain—as examples of regulatory approaches in other countries, 

focusing on the residue limits they set. We did not examine how, or the 

extent to which, these countries monitor or enforce their pesticide residue 

limits. We updated and clarified the information on the three countries’ 

residue limits provided in the articles with information from the 

Cooperation Centre for Scientific Research Relative to Tobacco 

(CORESTA), an international tobacco research organization, and officials 

responsible for oversight of pesticides and tobacco in Germany and Spain. 

To identify countries that import U.S. tobacco, we extracted data from the 

United States International Trade Commission’s interactive tariff and trade 

database on the countries that received U.S. flue-cured and burley tobacco 

from 1996 through 2001. 

We conducted our review from May 2002 through March 2003 in 

accordance with generally accepted government auditing standards. 
Appendix II: Pesticide Use on Tobacco and 

Other Crops 

Page 37 GAO-03-485 Pesticides on Tobacco 

Most of the pesticides used on tobacco are widely used on food and other 

crops. As shown in table 6, tobacco use of most pesticides represents a 

small portion of the total use. However, for some pesticides—

dimethomorph, fenamiphos, flumetralin, maleic hydrazide, mefenoxam, 

and sulfentrazone—most of the use in 1994 through 1998 was on tobacco. 

Table 6: Pesticide Use on Tobacco and All Crops, 1990-98 

Use in pounds—1992 survey (1990-93) Use in pounds—1997 survey (1994-98) 

Pesticide Tobacco All crops Tobacco All crops 

1,3-dichloropropene 

(1,3-D) 11,537,540 40,083,611 13,279,285 34,717,237 

Chloropicrin 577,082 11,086,567 6,761,644 13,882,188 

Maleic hydrazide 1,789,208 2,073,238 1,790,089 2,143,154 

Acephate 1,570,457 3,389,865 871,899 2,462,354 

Methyl bromide 5,356,748 44,196,554 685,026 32,803,943 

Pendimethalin 321,931 20,281,766 473,718 27,284,718 

Chlorpyrifos 685,554 14,764,535 406,822 13,463,879 

Fenamiphos 257,142 614,937 379,841 726,675 

Mancozeb a 8,062,374 356,811 9,585,777 

Flumetralin a a 352,742 352,742 

Metalaxyl 371,645 855,400 271,368 659,997 

Clomazone a 1,801,776 217,617 2,531,160 

Ethoprop 438,274 1,449,743 182,321 1,010,807 

Endosulfan a

 1,796,726 172,766 1,601,195 

Mefenoxam a a 139,199 210,101 

Pebulate 412,000 673,046 131,665 343,322 

Ethephon 113,238 2,701,284 102,130 5,407,986 

Napropamide 191,840 500,695 92,622 448,400 

Sulfentrazone a a 69,073 69,073 

Imidacloprid a a 67,896 272,207 

Aldicarb 159,044 4,022,468 59,719 4,277,552 

Dimethomorph a a 36,818 51,536 

Methomyl 57,137 2,754,907 29,773 1,997,489 

Malathion 7,549 3,377,678 15,437 5,809,943 

Disulfoton 52,578 1,806,527 13,495 1,196,066 

Sethoxydim a

 1,350,566 9,579 1,717,271 

Spinosad a a 2,815 117,315 

Carbaryl 16,487 4,570,414 2,057 4,857,542 

Fonofos 12,798 3,233,797 16 417,372 

Benefin 56,963 478,205 a 161,983 

Bacillus thuringiensis b b b b

Carbofuran 149,965 5,101,406 a 3,398,067 

Diazinon 53,670 1,265,739 a 918,087 

Diphenamid 81,624 105,009 a a

Appendix II: Pesticide Use on Tobacco and 

Other Crops 
Appendix II: Pesticide Use on Tobacco and 

Other Crops 

Page 38 GAO-03-485 Pesticides on Tobacco 

Use in pounds—1992 survey (1990-93) Use in pounds—1997 survey (1994-98) 

Pesticide Tobacco All crops Tobacco All crops 

Isopropalin 129,287 129,287 a a

Methidathion 68 372,953 a 314,091 

Trichlorfon 722 13,974 a a

Grand total 24,400,552 182,915,047 26,974,241 175,211,229 

Source: National Center for Food and Agricultural Policy. 

a

Not identified as being used in survey. 

b

Neither survey estimated the use of Bacillus thuringiensis in pounds. 
Appendix III: Germany, Italy, and Spain Have 

Adopted Regulatory Limits for Pesticide 

Residues on Tobacco 

Page 39 GAO-03-485 Pesticides on Tobacco 

Several countries that are major importers of U.S. tobacco have adopted 

regulations for specific pesticide residues on various forms of tobacco. 

For example, Germany’s residue limits (maximum residue levels) apply to 

finished products, such as cigarettes, whereas limits in Italy and Spain 

generally apply to tobacco leaf. Although they have somewhat different 

regulatory approaches to pesticides on tobacco, Germany, Italy, and Spain 

differ from the United States in that they regulate residues of pesticides 

approved for use on tobacco in addition to regulating some residues of 

pesticides not approved for use on tobacco. 

According to 2003 data from CORESTA—the Cooperation Centre for 

Scientific Research Relative to Tobacco—Germany, Italy, and Spain have 

residue limits on tobacco for 79, 100, and 58 pesticides, respectively.1

 Of 

the 37 pesticides commonly used on tobacco in the United States during 

the 1990s, Germany has limits for 20, Italy for 24, and Spain for 21 (see 

table 7). None of these countries have adopted limits for 7 of the pesticides 

commonly used on U.S. tobacco during the 1990s.2

Table 7: Residue Limits Adopted by Germany, Italy, and Spain for Pesticides 

Commonly Used on Tobacco in the United States during the 1990s 

Residue limits in ppm (country) 

Pesticide Germanya Italyb Spainc

Acephate d 1.5 d 

Aldicarb 10.0 0.6 (green) 

3.0 (cured) 

5.0 

Benefin d 0.01 0.02 

Carbaryl 3.0 3.0 0.1 

Carbofuran 20.0 0.1 10.0 

Chlorpyrifos d 0.2 0.05 

Diazinon 1.0 d 0.02 

Dichloropropene d d 0.05 

Diphenamid 1.5 0.1 5.0 

Disulfoton 1.0 0.4 d 

Endosulfan 20.0 1.0 d 

 1

CORESTA is an international research association whose members are companies and 

research institutes having research and development activities related to tobacco. It has 

190 members from 52 countries. 

2

The seven pesticides are Bacillus thuringiensis, chloropicrin, clomazone, dimethomorph, 

mefanoxam, spinosad, and sulfentrazone. 

Appendix III: Germany, Italy, and Spain Have 

Adopted Regulatory Limits for Pesticide 

Residues on Tobacco 
Appendix III: Germany, Italy, and Spain Have 

Adopted Regulatory Limits for Pesticide 

Residues on Tobacco 

Page 40 GAO-03-485 Pesticides on Tobacco 

Residue limits in ppm (country) 

Pesticide Germanya Italyb Spainc

Ethephon d 16.0 (green) 

80.0 (cured) d 

Ethoprop 3.0 0.02 0.02 

Fenamiphos 15.0 0.1 0.02 

Flumetralin 

20.0 

2.0 (green) 

10.0 (cured) 5.0 

Fonophos 1.0 0.05 d 

Imidacloprid d 10.0 (green) 

 50.0 (cured) 5.0 

Isopropalin 0.5 0.02 d 

Malathion 3.0 0.5 0.5 

Maleic hydrazide 80.0 80.0a

 80.0 

Mancozeb 

50.0e

2.0 (green) 

10.0f

 (cured) 0.05g

Metalaxyl d 1.0 3.0 

Methidathion 1.0 d d 

Methomyl 2.0 d d 

Methyl bromide d d 20.0 

Napropamide 0.1 0.1 0.05 

Pebulate 0.5 d 0.05 

Pendimethalin d 0.05 0.05 

Sethoxydim d 0.5 d 

Trichlorfon 1.0 0.1 0.1 

Number of limits for 

commonly used 

pesticides 20 24 21 

Source: CORESTA and European Court of Auditors. 

Note: GAO’s analysis of CORESTA and European Court of Auditors data. 

a

Residue limit on finished products. 

b

Residue limit on green tobacco if not otherwise specified. 

c

Residue limit on dried tobacco. 

d

Country has not adopted limits for this pesticide. 

e

Residue limit established for the entire class of dithiocarbamates except metam. 

f

Residue limit established for the entire class of dithiocarbamates except thiram. 

g

Residue limit established for the entire class of dithiocarbamates except metam and thiram. 

In addition to residue limits for approved pesticides, Germany and Italy 

collectively have residue limits on tobacco that apply to 15 of the 20 

pesticides not approved for use in the United States that USDA monitors in 

its tobacco testing programs. The 15 pesticides are aldrin, dieldrin, 

chlordane, cypermethrin, DDT, DDE, endrin, ethylene dibromide, 

formothion, heptachlor, heptachlor epoxide, hexachlorobenzene, 
Appendix III: Germany, Italy, and Spain Have 

Adopted Regulatory Limits for Pesticide 

Residues on Tobacco 

Page 41 GAO-03-485 Pesticides on Tobacco 

methoxychlor, permethrin, and TDE. Further, where no specific pesticide 

limits are set for tobacco products in Germany, residues of pesticides not 

approved for use on tobacco in Germany may be present in amounts that 

are not likely to pose a risk to human health. In Italy and Spain, residues of 

pesticides not approved for use on tobacco in those countries must not 

exceed the limit of detection, generally between 0.01 ppm and 0.05 ppm. 

We did not examine how, or the extent to which, these countries monitor 

or enforce their pesticide residue limits. 

From 1971 to 2000, researchers at the North Carolina State University 

(NCSU) collected limited data on the residues of various pesticides on 

some domestically grown tobacco. NCSU data for the 1990s included six 

pesticides for which Germany, Italy, or Spain have residue limits. The 

domestic tobacco tested by NCSU identified residue levels that were 

(1) consistently below the lowest limit for endosulfan, flumetralin, and 

metalaxyl; (2) generally above the limit for maleic hydrazide;3

 and (3) more 

varied for fenamiphos and the dithiocarbamates—a class of fungicides 

that includes mancozeb. For example, in 1995 residue levels on flue-cured 

tobacco were below the lowest limit for fenamiphos—0.02 ppm adopted 

by Spain—but exceeded this limit in 1992 and 1994. Also, in 1991 and 1997 

residue levels of dithiocarbamates were generally lower on burley tobacco 

than limits in Germany and Italy—50 ppm and 10 ppm, respectively—but 

exceeded Spain’s limit of 0.05 ppm. 

 3

According to tobacco experts with whom we spoke, tobacco with high levels of maleic 

hydrazide may be blended with tobacco from other sources to reduce overall maleic 

hydrazide levels. 
Appendix IV: USDA Tests Domestic Tobacco 

in the Loan Stock Program 

Page 42 GAO-03-485 Pesticides on Tobacco 

The USDA Farm Service Agency (FSA)1 tests the portion of domestically 

grown flue-cured and burley tobacco that becomes loan stock (surplus 

tobacco) under USDA’s tobacco price support program for the 20 

regulated pesticides.2 To receive price supports, tobacco must be sold in 

USDA-approved auction warehouses and inspected by USDA graders. At 

the auction warehouse, each individual lot of tobacco is sold to the highest 

bidder. If the highest bid is below the government’s loan (support) price, 

or no bid is received, the stabilization cooperative makes loans to growers 

whose tobacco does not bring the minimum price at auction with funds 

borrowed from USDA’s Commodity Credit Corporation. The growers’ 

tobacco, which is consigned to the cooperative as loan stock, is pledged as 

collateral to the credit corporation for the money borrowed. The 

cooperative receives, processes, stores, and later sells the loan stock 

tobacco when demand increases, with the proceeds used to repay the 

credit corporation loan, plus interest. An alternative to traditional auction 

marketing—growers contracting to sell their tobacco directly to 

manufacturers—also reduces the amount of tobacco going to auction and 

thus potentially to loan stock. For the most recently completed marketing 

season—growing year 2001—20 percent of domestic tobacco was sold at 

auction, and 2.4 percent became loan stock. 

After auction, the tobacco is processed in distinct “runs” of approximately 

100,000 pounds, when the tobacco is stemmed, redried, finely chopped, 

and placed into boxes holding approximately 440 pounds. The tobacco 

cooperative randomly selects one box from each run and draws a 

one-pound sample of tobacco for pesticide testing at USDA’s laboratory. If 

the sample exceeds any of the residue limits, the box of tobacco from 

which it came is destroyed. The adjacent boxes, processed before and 

after the original box, are also sampled. The testing continues with 

adjacent boxes of tobacco until the samples are found to be below the 

residue limits. Because the samples are drawn by the tobacco 

cooperatives, FSA resamples 5 percent of the tested inventory (or 25 

samples, whichever is less) for oversight purposes each year. 

 1

FSA was formed in 1994 from programs in several agencies, including tobacco programs 

from the former Agricultural Stabilization and Conservation Service. 

2

The price support program is administered by stabilization cooperatives—owned by 

tobacco growers—under agreement with USDA’s Commodity Credit Corporation and 

auction warehouses. 

Appendix IV: USDA Tests Domestic Tobacco 

in the Loan Stock Program 
Appendix IV: USDA Tests Domestic Tobacco 

in the Loan Stock Program 

Page 43 GAO-03-485 Pesticides on Tobacco 

Historically a substantial portion of domestic tobacco was sold at auctions 

in conjunction with the tobacco price support program, but in recent years 

most domestic tobacco has been sold under contract directly to cigarette 

manufacturers—approximately 80 percent in 2001. Officials from USDA 

and tobacco associations told us the market has changed because 

manufacturers asserted that auction markets were not providing quality 

tobacco with the characteristics they required. The recent, dramatic shift 

in the way tobacco is marketed—with a 60 to 80 percent reduction in the 

amount of tobacco at auction—has decreased the amount of domestic 

tobacco that potentially becomes loan stock and thus is tested. Although 

the amount of domestically produced tobacco that becomes loan stock 

has varied greatly, an average of 13 percent became loan stock over the 

past decade. In 2001, only about 2 percent of domestically produced 

tobacco has become loan stock, reducing the amount of domestic tobacco 

subjected to pesticide testing. The officials with whom we spoke said that 

this change is not likely to be reversed. 
Appendix V: GAO Contacts and Staff 

Acknowledgments 

Page 44 GAO-03-485 Pesticides on Tobacco 

John B. Stephenson, (202) 512-3841 

Christine Fishkin, (202) 512-6895 

In addition to those named above, Nancy Crothers, Laura Gatz, Terrance 

Horner, Richard Johnson, Ilga Semeiks, Tina Smith, and Cheryl Williams 

made key contributions to this report. 

Appendix V: GAO Contacts and Staff 

Acknowledgments 

GAO Contacts 

Acknowledgments 

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