Docket Number EPA-HQ-OPP-2010-0752 

www.regulations.gov

Sodium Cyanide (M-44) Summary Document 

Registration Review: Initial Docket 

September 2010 

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TABLE OF CONTENTS 

 Page # 

I. Preliminary Work Plan (PWP) 4 

II. Fact Sheet 10 

 

This Preliminary Work Plan and Fact Sheet summarize the Environmental Protection Agency’s 

current position based on the following documents: 

1. EFED Registration Review Problem Formulation for Sodium Cyanide (M-44), September 

20, 2010 

2. Sodium Cyanide: Human Health Risk Scoping Document in Support of Registration 

Review, September 8, 2010 

3. Food/Feed & Non-Food/Non-Feed Uses Considered in Registration 

Review Work Planning – Sodium cyanide (074002), July 6, 2009 

4. Sodium cyanide (074002) California Department of Pesticide Regulation (CADPR) 

Usage Data, November 3, 2009 

5. Sodium Cyanide: Review of Human Incidents, May 20, 2010 

6. Environmental Protection Agency’s (EPA) Response to the Petition and Addenda 

Requesting that EPA Suspend and Cancel the Registrations of the Predator Control Uses 

of Sodium Cyanide and Sodium Fluoroacetate (Compound 1080), January 16, 2009 

All supporting documents for the registration review of sodium cyanide are located in docket 

EPA-HQ-OPP-2010-0752 at http://www.regulations.gov. 
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I. PRELIMINARY WORK PLAN – Sodium Cyanide 

Introduction

The Food Quality Protection Act (FQPA) of 1996 mandated a registration review 

program. All pesticides distributed or sold in the United States (U.S.) generally must be 

registered by the Environmental Protection Agency (EPA or the Agency), based on scientific 

data showing that they will not cause unreasonable risks to human health or the environment 

when used as directed on product labeling. The registration review program is intended to make 

sure that, as the ability to assess risk evolves and as policies and practices change, all registered 

pesticides continue to meet the statutory standard of no unreasonable adverse effects to human 

health or the environment. Changes in science, public policy, and pesticide use practices will 

occur over time. Through the registration review program, the Agency periodically reevaluates 

pesticides to make sure that as change occurs, products in the marketplace can be used safely. 

Information on this program is provided at: http://www.epa.gov/oppsrrd1/registration_review/ . 

The Agency is implementing the registration review program pursuant to Section 3(g) of 

the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA), and will review each 

registered pesticide every 15 years to determine whether it continues to meet the FIFRA standard 

for registration. The Agency will consider benefits information and data as required by FIFRA. 

The public phase of registration review begins when the initial docket is opened for each case. 

The docket is the Agency’s opportunity to state what it knows about the pesticide and what 

additional risk analyses and data or information it believes are needed to make a registration 

review decision. After reviewing and responding to comments and data received in the docket 

during this initial comment period, the Agency will develop and commit to a final work plan and 

schedule for the registration review of sodium cyanide. 

 Sodium cyanide was initially registered in the United States as a pesticide in 1947. A 

Reregistration Eligibility Decision (RED) and Tolerance Reassessment Eligibility Decision 

(TRED) for sodium cyanide were issued in 1994 and 2006, respectively. Sodium cyanide is 

currently registered as a restricted use predicide and as a restricted use insecticide. As a 

predicide, sodium cyanide is manufactured as an encapsulated single dose poison, which is 

inserted into an M-44 spring-loaded ejector device, to control animals (foxes, coyotes, feral 

dogs) that prey upon livestock or threatened or endangered species. Sodium cyanide is not 

currently registered for any food or feed uses. However, there is one Special Local Needs (SLN) 

registration under Section 24(c) for use in California as an insecticide in which sodium cyanide 

is used as a source of hydrocyanic gas for quarantine fumigation of surface pests on citrus bound 

for Arizona. 

A summary of the issues relevant to the registration review of sodium cyanide is 

presented below. 
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Anticipated Risk Assessment and Data Needs

A new ecological risk assessment and additional ecological toxicity and environmental 

fate data are not anticipated as being needed for sodium cyanide in support of registration 

review. However, as outlined in the Agency’s response to the petition and addenda (filed on 

January 24, 2007, March 20, 2007, July 27, 2007 and January 7, 2008) requesting that EPA 

suspend and cancel the registration of the predator control uses of sodium cyanide (M-44) and 

sodium fluoroacetate (Compound 1080), the Agency will conduct an endangered species risk 

assessment for all uses of sodium cyanide. A new human health risk assessment and additional 

data are not needed for sodium cyanide in support of registration review. 

Ecological Risk: 

• As part of the Agency’s response to the petition and addenda requesting that EPA 

suspend and cancel the registration of the predator control uses of sodium cyanide (M-44) 

and sodium fluoroacetate (Compound 1080), the Agency has initiated informal 

consultation with the United States Fish and Wildlife Service (USFWS) and intends to 

reinitiate formal consultation with the USFWS as part of this registration review. 

• On April 15, 1991 EPA initiated consultation for 16 vertebrate control agents including 

sodium cyanide used in M-44 spring-loaded ejectors. The USFWS issued a Biological 

Opinion (BO) in March 1993. For M-44, the BO found that this registration could affect 

the Florida panther, gray wolf, grizzly bear, jaguarondi, Louisiana black bear, ocelot, San 

Joaquin kit fox, California condor, Hawaiian crow, and the Mariana crow. FWS 

determined that if certain reasonable and prudent alternatives and measures were adopted, 

the registration would not jeopardize the continued existence of these species. The 

sodium cyanide M-44 labels were amended to identify the specific listed species. In the 

1994 RED EPA concluded that the use of M-44 did not pose unreasonable risks to the 

environment if the product was used in accordance with the established use restrictions. 

Per this registration review, EPA will reinitiate formal consultations with FWS in 

accordance with Section 7 of the Endangered Species Act (USFWS/NMFS, 1998) to 

confirm that the current measures remain adequately protective of listed species 

identified in the 1993 BO and if necessary will recommend additional measures for new 

listed species. 

• For further information please refer to the EFED Registration Review Problem 

Formulation for Sodium Cyanide (M-44) (September 20, 2010), which is available in the 

docket at: http://www.regulations.gov

Human Health Risk: 

• EPA has reviewed the existing toxicology database and most recent human health 

exposure and risk assessments for sodium cyanide and has determined that these data and 
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assessments are adequate based on current methodologies. Therefore, a new human 

health risk assessment and additional data are not anticipated as being needed in support 

of registration review. 

• EPA does not anticipate needing immunotoxicity data because available toxicity data 

provide no evidence of immunotoxic potential for cyanide compounds. Additionally, 

metabolism studies indicate that cyanide is metabolized to naturally occurring 

constituents that are not likely to provoke an immune response. 

• The tolerance expression in 40 CFR 180.130 will be reviewed during registration review 

to ensure that it appropriately covers the metabolites and degradates of sodium cyanide 

and that it specifies the residues to be measured for each commodity. 

• For further information please refer to the Sodium Cyanide: Human Health Assessment 

Scoping Document in Support of Registration Review (September 8, 2010), which is 

available in the docket at at: http://www.regulations.gov

Endocrine Disruptor Screening Program

As required under FFDCA section 408(p), EPA has developed the Endocrine Disruptor 

Screening Program (EDSP) to determine whether certain substances (including pesticide active 

and other ingredients) may have an effect in humans or wildlife similar to an effect produced by 

a “naturally occurring estrogen, or other such endocrine effects as the Administrator may 

designate.” The EDSP employs a two-tiered approach to making the statutorily required 

determinations. Tier 1 consists of a battery of 11 screening assays to identify the potential of a 

chemical substance to interact with the estrogen, androgen, or thyroid (E, A, or T) hormonal 

systems. Chemicals that go through Tier 1 screening and are found to have the potential to 

interact with E, A, or T hormonal systems will proceed to the next stage of the EDSP where EPA 

will determine which, if any, of the Tier 2 tests are necessary based on the available data. Tier 2 

testing is designed to identify any adverse endocrine related effects caused by the substance, and 

establish a quantitative relationship between the dose and the E, A, or T effect. 

Between October 2009 and February 2010, EPA issued test orders/data call-ins for the 

first group of 67 chemicals, which contains 58 pesticide active ingredients and 9 inert 

ingredients. This list of chemicals was selected based on the potential for human exposure 

through pathways such as food and water, residential activity, and certain post-application 

agricultural scenarios. This list should not be construed as a list of known or likely endocrine 

disruptors. 

Sodium cyanide is not among the group of 58 pesticide active ingredients on the initial 

list to be screened under the EDSP. Under FFDCA sec. 408(p) the Agency must screen all 

pesticide chemicals. Accordingly, EPA anticipates issuing future EDSP orders/data call-ins for 
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all Registration Review cases, including those for which EPA has already opened a Registration 

Review docket for a pesticide active ingredient. 

For further information on the status of the EDSP, the policies and procedures, the list of 

67 chemicals, the test guidelines and the Tier 1 screening battery, please visit our website: 

http://www.epa.gov/endo/. 

Timeline

 

The Agency has created the following estimated timeline for the completion of the 

sodium cyanide registration review. 

Registration Review for Sodium Cyanide – Projected Registration Review Timeline

Activities Estimated Date 

Opening the docket 

Open Docket and Public Comment Period 2010 – September 

Close Public Comment 2010 – November 

Case Development 

Final Work Plan 2011 – February 

Open Public Comment Period for Preliminary Risk Assessments 2013 – Jan.- March 

Close Public Comment Period 2013 – April – June 

Registration Review Decision 

Open Public Comment Period for Proposed Registration Review 

Decision 

2013 – July – Sept. 

Close Public Comment Period 2013 – Oct. – Dec. 

Final Registration Review Decision and Begin Post-Decision Follow-up 2014 

Total (years) 4 

Guidance for Commenters

The public is invited to comment on EPA’s preliminary registration review work plan 

and rationale. The Agency will carefully consider all comments, as well as any additional 

information or data provided in a timely manner, prior to issuing a final work plan for the sodium 

cyanide case. 

Trade Irritants: 

Through the registration review process, the Agency intends to solicit information on 

trade irritants and, to the extent feasible, take steps toward facilitating irritant resolution. 

Growers and other stakeholders are asked to comment on any trade irritant issues resulting from 

lack of Maximum Residue Limits (MRLs) or disparities between U.S. tolerances and MRLs in 
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key export markets, providing as much specificity as possible regarding the nature of the 

concern. 

Environmental Justice: 

EPA seeks to achieve environmental justice, the fair treatment and meaningful 

involvement of all people, regardless of race, color, national origin, or income, in the 

development, implementation, and enforcement of environmental laws, regulations, and policies. 

To help address potential environmental justice issues, the Agency seeks information on any 

groups or segments of the population who, as a result of their location, cultural practices, or other 

factors, may have atypical, unusually high exposure to sodium cyanide compared to the general 

population. Please comment if you are aware of any sub-populations that may have atypical, 

unusually high exposure, compared to the general population. 

Water Quality: 

Sodium Cyanide is not identified as a cause of impairment for any water bodies listed as 

impaired under section 303(d) of the Clean Water Act, based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation_cv.cause_detail_303d?p_cause_group_id=88

5. In addition, no Total Maximum Daily Loads (TMDL) have been developed for sodium 

cyanide, based on information provided at 

http://iaspub.epa.gov/tmdl_waters10/attains_nation.tmdl_pollutant_detail?p_pollutant_group_id

=885&p_pollutant_group_name=PESTICIDES. More information on impaired water bodies and 

TMDLs can be found at http://www.epa.gov/owow/tmdl/. The Agency invites submission of 

water quality data for this pesticide. To the extent possible, data should conform to the quality 

standards in Appendix A of the OPP Standard Operating Procedure: Inclusion of Impaired 

Water Body and Other Water Quality Data in OPP’s Registration Review Risk Assessment and 

Management Process (see: 

http://www.epa.gov/oppsrrd1/registration_review/water_quality_sop.htm), in order to ensure 

they can be used quantitatively or qualitatively in pesticide risk assessments. 

Additional Information: 

Stakeholders are also specifically asked to provide information and data that will assist the 

Agency in refining risk assessments, including any species-specific ecological effects 

determinations. The Agency is interested in receiving any ecological incidents information 

specific to sodium cyanide (non-target and avian and mammalian mortalities) that has not 

already been reported to the Agency. 
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Next Steps

After the 60-day comment period closes, the Agency will review and respond to any 

comments received in a timely manner and then expects to issue a Final Work Plan in December 

of 2010 for sodium cyanide. 
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II. FACT SHEET 

Background Information

• Sodium cyanide registration review case number: 8002 

• PC Code: 074002 ; CAS # 143-33-97 

• Sodium cyanide was first registered in the United States in 1947 

• A Reregistration Eligibility Decision (RED) was issued in 1994 

• A Tolerance Reassessment Eligibility Decision (TRED) was issued in 2006 

• Technical registrant: United States Department of Agriculture, Animal Plant Health 

Inspection Service (USDA, APHIS) 

• There is one Special Local Needs (SLN) food/feed use registration under Section 24(C) 

for use as an insecticide; and there are 8 FIFRA Section 3 active product registrations for 

use as a predicide. 

• A tolerance of 50 ppm is established under 40 CFR §180.130 for residues of hydrogen 

cyanide resulting from use of sodium cyanide in/on fruit and citrus. 

• Pesticide Re-evaluation Division Contact: K. Avivah Jakob (Jakob.kathryn@epa.gov) 

• Registration Division Contact: Bill Jacobs (Jacobs.bill@epa.gov) 

Use and Usage Information 

For additional details, please refer to Food/Feed & Non-Food/Non-Feed Uses 

Considered in Registration Review Work Planning – Sodium cyanide (074002) (July 6, 2009) in 

the sodium cyanide docket. 

• Sodium cyanide is classified as a restricted use pesticide (RUP) that may only be applied 

by certified applicators for both predicide and insecticide uses. 

• Sodium cyanide is registered for use to control coyotes, red foxes, gray foxes and wild 

dogs that are: suspected of preying on livestock; suspected of preying on threatened or 

endangered species; or are vectors of communicable diseases. 

• As a predicide sodium cyanide is formulated as a powder enclosed in polyethylene 

capsules containing 88.78%-91.06% active ingredient. 

• Each capsule is loaded into a capsule holder, which is screwed onto the ejector 

mechanism of an M-44. The capsule holder is treated with a scent formulated to attract 

canids. When an animal tugs at the capsule holder, a spring-driven plunger ejects sodium 

cyanide powder into the animal’s mouth causing the death of the animal. 

• Sodium cyanide is also registered as an insecticide for one Special Local Needs (SLN) 

registration that is used in California. As an insecticide (SLN registration) sodium 

cyanide is used as a source of hydrocyanic gas for quarantine fumigation of surface pests 

to control red scale on fresh market citrus bound for Arizona. 

• The SLN end-use product is formulated as a granular containing 98% sodium cyanide as 

the active ingredient. It is applied by professional applicators only. 
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Pending and Recent Actions

• In January 2009 EPA issued a response to the petition and addenda filed January 24, 

2007, March 20, 2007, July 27, 2007 and January 7, 2008 requesting that EPA suspend 

and cancel the registration of the predator control uses of sodium cyanide and sodium 

fluroacetate. EPA denied the request to suspend and cancel the predator control uses of 

these two chemicals because it was determined that the use of these devises does not 

create unreasonable adverse effects on the environment under FIFRA and that the 

registrations meet the FIFRA eligibility standards. 

• In August 2010 the Agency amended APHIS M-44 registrations with updated label 

language to add more clarity to the use restrictions established in 1994. 

• EPA is currently working with the States to amend all FIFRA Section 3 registration 

labels to reflect the recently revised label language.

Ecological Risk Assessment Status

The following are key findings of the ecological risk assessments conducted to support 

the registered uses of sodium cyanide. For a detailed discussion of previous ecological risk 

assessments refer to the EFED Registration Review Problem Formulation for Sodium Cyanide 

(M-44) (September 20, 2010), which is located in the docket. 

• The most recent ecological risk assessment was completed in 1994 in support of the 

sodium cyanide Reregistration Eligibility Decision (RED). 

• The primary environmental concern identified in previous risk assessments was the 

potential risk for direct effects on non-target birds and mammals when the M-44 sodium 

cyanide devices are triggered and M-44 is injected into the non-target animal’s mouth. 

• In the 1994 RED EPA concluded that the use of M-44 did not pose unreasonable risks to 

the environment if this product was used in accordance with the use restrictions. 

• The 1993 Biological Opinion (BO) found that the use of M-44 sodium cyanide 

registrations could affect several listed species. However, FWS determined that if certain 

reasonable and prudent alternatives and measures were adopted, the registration would 

not jeopardize the continued existence of these species. 

Human Health Risk Assessment Status

The following are key findings of the human health risk assessments conducted to 

support the registered uses of sodium cyanide. For a detailed discussion of the human health risk 
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assessment status refer to the Sodium cyanide. Human Health Assessment Scoping Document in 

Support of Registration Review (September 8, 2010), which is located in the docket. 

• The most recent human health risk assessment for the use of sodium cyanide as an 

insecticide to fumigate CA citrus bound for AZ was completed in 2006 in support of the 

Tolerance Reassessment Eligibility Decision (TRED). The 2006 risk assessment 

addressed dietary and occupational exposures and risks. 

• A human health risk assessment was conducted in 1994 in support of the sodium cyanide 

Reregistration Eligibility Decision (RED). The 1994 risk assessment addressed 

occupational exposure and risk from use of sodium cyanide as a predicide. 

Hazard Characterization: 

• All forms of cyanide are extremely acutely toxic by oral, dermal and inhalation routes of 

exposures. Cyanides are weakly irritating to the skin and eye. No data are available on 

sensitizing properties. 

• Based on available literature studies, neurotoxity is a major effect that occurs across 

species from exposure to cyanide in its various forms. Data indicate that cyanide induces 

developmental effects only at doses or concentrations that are overtly toxic to the 

maternal animals. 

• There are no guideline studies and no available open literature studies on the 

carcinogenic potential of cyanide. However, due to the acute lethality of cyanide, a 

carcinogenic evaluation is considered unnecessary. 

• There was no qualitative or quantitative increased susceptibility in postnatal offspring 

toxicity and there is a low degree of concern for residual uncertainties for pre and/or postnatal susceptibility. Therefore, the FQPA uncertainty safety factor was reduced to 1X for 

sodium cyanide. 

Dietary Risk: 

• In EPA’s 2006 risk assessment, dietary risk (food) estimates from all registered sodium 

cyanide uses were below the Agency’s level of concern. 

• Drinking water exposure was not quantitatively assessed because exposure is expected to 

be negligible based on available monitoring data. 

Residential and Recreational Risk: 

• There are no registered residential uses of sodium cyanide; therefore, residential exposure 

has not been previously assessed. 
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Aggregate Risk: 

• An aggregate exposure assessment has not been previously conducted because it is 

believed that sodium cyanide does not result in residential or drinking water exposure and 

dietary (food) exposure estimates are below the Agency’s level of concern. 

Occupational Risk: 

• Occupational risk associated with the use of sodium cyanide in bait products was last 

assessed in February 1994 in support of the RED. EPA concluded that there are no 

significant occupational applicator exposure concerns and that post-application exposure 

would be minimal to humans since label restrictions effectively limit exposure. 

• Occupational exposure to hydrogen cyanide, resulting from the use of sodium cyanide to 

fumigate citrus was last assessed in 2006. Dermal exposures were not expected based on 

the limited use pattern and were therefore not assessed. Inhalation exposures were 

assessed using monitoring data from fumigations conducted at the California facility. 

Based on this assessment, occupational exposure from use of sodium cyanide as a citrus 

fumigant are not of concern. 

Cumulative assessment: 

• EPA does not have available data to determine whether sodium cyanide has a common 

mechanism of toxicity with other substances. EPA has not made a common mechanism 

of toxicity finding for sodium cyanide and any other substances and, sodium cyanide 

does not appear to produce a toxic metabolite produced by other substances which have 

tolerances in the U. S. Therefore, EPA has not assumed that sodium cyanide has a 

common mechanism of toxicity with other substances. 

Incidents

• A preliminary review of the Ecological Incident Information System (EIIS) and the 

Avian Monitoring Information System (AIMS) Database identified forty-five terrestrial 

animal incidents, covering a period from 1983-2009. Three of these incidents are 

classified as misuses of M-44. The database records mortality for twenty-six birds, 

fifteen dogs, ten wolves, three fox and two bear. No aquatic incidents or plant incidents 

were reported in the EIIS database for M-44. 

• An updated review of sodium cyanide human incident reports was prepared by consulting 

the OPP Incident Data System (IDS) and the Centers for Disease Control and 

Prevention/National Institute for Occupational Safety and Health Sentinel Event 

Notification System for Occupational Risk-Pesticides. Six incidents have been reported 

from 2002 to present; one major incident, four moderate incidents, and one minor 

incident. The single major human incident occurred in 2003 when an adult male (18-64 

years old) was recreating on the Bureau of Land Management property. The man 
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brushed the top of a device accidentally and was subsequently exposed to product 

particles (on his face and chest). Blood tests confirmed exposure. The man stated that he 

had been unable to work since this incident due to long term effects such as difficulty in 

breathing and weakness. Four moderate incidents occurred when the product was ejected 

accidentally; the patients complained of eye irritation. A minor case did not have any 

symptoms; he stated that he administered amyl nitrite immediately after exposure to the 

product. 

Tolerances and International Harmonization

• A tolerance of 50 ppm has been established under 40 CFR §180.130 for hydrogen 

cyanide residues on citrus fruit, which result from the use of sodium cyanide for postharvest fumigation of citrus. Use of sodium cyanide as a fumigant is limited to citrus 

treated in California bound for Arizona and not for international export. Codex 

maximum residue limits (MRLs) do not currently exist for hydrogen cyanide. 

Data Call-In Status

• Generic data call-ins (GDCI) were issued in 1992 (GDCI-074002-17029), 1993 (GDCI074002-17373), and 2007 (GDCI-074002-26902). Data have been submitted and are 

currently being reviewed. 

• A product specific data call-in (PDCI) was issued in 1994 (PDCI-074002-0099). 

Labels 

• Active Section 3 labels for Sodium cyanide can be obtained from the Pesticide Product 

Label System (PPLS) website: http://oaspub.epa.gov/pestlabl/ppls.home.