Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34149 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Parts 85, 86, and 1039 

[EPA–HQ–OAR–2011–1032; FRL–9673–2] 

RIN 2060–AR46 

Heavy-Duty Highway Program: 

Revisions for Emergency Vehicles and 

SCR Maintenance 

AGENCY: Environmental Protection 

Agency (EPA). 

ACTION: Notice of proposed rulemaking. 

SUMMARY: This proposal consists of 

three parts. First, EPA is proposing 

revisions to its heavy-duty diesel 

regulations that would enable 

emergency vehicles, such as dedicated 

ambulances and fire trucks, to perform 

their mission-critical life-saving work 

without risking that abnormal 

conditions of the emission control 

system could lead to decreased engine 

power, speed or torque. The revisions 

would allow manufacturers to request 

and EPA to approve modifications to 

emission control systems on emergency 

vehicles so they do not interfere with 

the vehicles’ missions. Second, EPA is 

proposing to revise the emission-related 

maintenance and scheduled 

maintenance intervals for all motor 

vehicles and nonroad compressionignition engines to specify minimum 

maintenance intervals for replenishment 

of consumable chemical reductant in 

connection with the use of selective 

catalytic reduction technologies. Third, 

EPA is proposing to offer short-term 

relief for nonroad engines from 

performance inducements related to the 

emission control system, for general 

purpose nonroad vehicles while 

operating in temporary emergency 

service. These actions are not expected 

to result in any significant changes in 

regulatory burdens or costs. 

DATES: Comments on all aspects of this 

proposal must be received on or before 

July 27, 2012. See the SUPPLEMENTARY

INFORMATION section on ‘‘Public 

Participation’’ for more information 

about written comments. 

Public Hearings: EPA will hold a 

public hearing on Wednesday, June 27, 

2012 in Ann Arbor, Michigan. The 

hearing will start at 10 a.m. local time 

and will continue until everyone has 

had a chance to speak. For more 

information about the public hearing, 

see ‘‘How Do I Participate in the Public 

Hearing?’’ under the SUPPLEMENTARY

INFORMATION section on ‘‘Public 

Participation’’ below at Section VIII.B. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–HQ– 

OAR–2011–1032, by one of the 

following methods: 

• www.regulations.gov: Follow the 

on-line instructions for submitting 

comments. 

• Email: a-and-r-docket@epa.gov. 

• Fax: (202) 566–9744. 

• Mail: Environmental Protection 

Agency, Air Docket, Mail-code 6102T, 

1200 Pennsylvania Ave. NW., 

Washington, DC 20460. 

• Hand Delivery: EPA Docket Center 

(EPA/DC), EPA West, Room 3334, 1301 

Constitution Ave. NW., Washington, 

DC, Attention Docket No. EPA–HQ– 

OAR–2011–1032. Such deliveries are 

only accepted during the Docket’s 

normal hours of operation, and special 

arrangements should be made for 

deliveries of boxed information. 

Instructions: Direct your comments to 

Docket ID No. EPA–HQ–OAR–2011– 

1032. For additional instructions on 

submitting written comments, see the 

SUPPLEMENTARY INFORMATION section on 

‘‘Public Participation’’ below at Section 

VIII.A. 

Docket: All documents in the docket 

are listed in the www.regulations.gov 

index. Although listed in the index, 

some information is not publicly 

available, e.g., confidential business 

information or other information whose 

disclosure is restricted by statute. 

Certain other material, such as 

copyrighted material, will be publicly 

available only in hard copy in the 

docket. Publicly available docket 

materials are available either 

electronically in www.regulations.gov or 

in hard copy at the EPA Docket Center, 

EPA/DC, EPA West, Room 3334, 1301 

Constitution Ave. NW., Washington, 

DC. The Public Reading Room is open 

from 8:30 a.m. to 4:30 p.m., Monday 

through Friday, excluding legal 

holidays. The telephone number for the 

Public Reading Room is (202) 566–1744, 

and the telephone number for the Air 

Docket is (202) 566–1742. 

FOR FURTHER INFORMATION CONTACT: 

Lauren Steele, Environmental Protection 

Agency, Office of Transportation and 

Air Quality, Assessment and Standards 

Division, 2000 Traverwood Drive, Ann 

Arbor, Michigan 48105; telephone 

number: 734–214–4788; fax number: 

734–214–4816; email address: 

steele.lauren (@epa.gov). 

SUPPLEMENTARY INFORMATION: 

Does this action apply to me? 

This proposed action would affect 

you if you produce or import new 

heavy-duty or nonroad diesel engines 

that are intended for use in vehicles that 

serve the emergency response industry, 

including all types of dedicated and 

purpose-built fire trucks and 

ambulances. You may also be affected 

by this action if you manufacture diesel 

engines that make use of a consumable 

chemical reductant to comply with 

emissions standards for nitrogen oxides. 

You may also be affected by this action 

if you produce or import diesel engines 

for nonroad applications. The following 

table gives some examples of entities 

that may be affected by this proposed 

action. Because these are only examples, 

you should carefully examine the 

proposed and existing regulations in 40 

CFR parts 85, 86 and 1039. If you have 

questions regarding how or whether 

these rules apply to you, you may call 

the person listed in the FOR FURTHER

INFORMATION CONTACT section above. 

Category NAICS 

Codes a Examples of potentially regulated entities 

Industry ..................................................... 336111 

336112 

333618 

336120 

Engine and Truck Manufacturers 

Industry ..................................................... 541514 

811112 

811198 

Commercial Importers of Vehicles and Vehicle Components 

Industry ..................................................... 811310 Engine Repair, Remanufacture, and Maintenance 

Note: 

a North American Industry Classification System (NAICS). 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
34150 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

Table of Contents 

I. Overview 

A. Emergency Vehicle Provisions 

B. Diesel Exhaust Fluid Provisions 

C. Nonroad Equipment Used Temporarily 

in Emergency Service 

II. Statutory Authority and Regulatory 

Background 

A. Statutory Authority 

B. Background: 2007 and 2010 NOX and 

PM Standards 

(1) On-Highway Standards 

(2) Nonroad Standards 

III. Direct Final Rule 

IV. Emergency Vehicle Provisions 

A. Background on Regulation of Emergency 

Vehicles 

B. Current Provisions for Other Emergency 

Vehicles and Engines 

C. Why is EPA taking this action? 

(1) How does a DPF work? 

(2) Why are emergency vehicles having 

problems with DPF regeneration? 

(3) What are the concerns for emergency 

vehicles using SCR? 

D. What would occur if EPA took no 

action? 

(1) The Industry Would Continue to Get 

Smarter 

(2) The Fleet Would Continue to Migrate to 

the 2010 Standards 

(3) Some Trucks Would Continue to 

Experience Problems 

E. Proposed Regulatory Action 

(1) Liberalized Regeneration Requests 

(2) Engine Recalibration 

(3) Backpressure Relief 

F. What engines and vehicles would be 

affected? 

(1) Newly Certified Engines and Vehicles 

(2) Certified Engines and Vehicles In-Use 

(3) Labeling Requirements 

(4) Other Regulatory Provisions 

V. Scheduled Maintenance and Maintenance 

Interval for Replacement of Diesel 

Exhaust Fluid 

A. Background 

B. Proposed Regulatory Action 

(1) Scheduled Emission-Related 

Maintenance 

(2) Maintenance Intervals for On-Highway 

Diesel Engines 

(3) Maintenance Intervals for Nonroad 

Compression-Ignition Engines 

VI. Nonroad Engines in Temporary 

Emergency Service 

A. Use of Nonroad Engines in Emergency 

Situations 

B. Proposed Regulatory Action 

(1) General Requirements 

(2) Approval Criteria 

(3) Allowable Use of Emergency AECD’s 

VII. Economic, Environmental, and Health 

Impacts of Proposed Rule 

A. Economic Impacts 

(1) Economic Impacts of Emergency 

Vehicle Proposal 

(2) Economic impacts of SCR Maintenance 

Proposal 

(3) Economic Impacts for Nonroad Engines 

Used in Emergency Situations 

B. Environmental Impacts 

(1) Environmental Impacts of Emergency 

Vehicle Proposal 

(2) Environmental Impacts of SCR 

Maintenance Proposal 

(3) Environmental Impacts for Nonroad 

Engines Used in Emergency Situations 

C. Health Effects 

VIII. Public Participation 

A. How do I submit comments? 

B. Will there be a public hearing? 

IX. Statutory and Executive Order Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

B. Paperwork Reduction Act 

C. Regulatory Flexibility Act 

D. Unfunded Mandates Reform Act 

E. Executive Order 13132: Federalism 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

and Safety Risks 

H. Executive Order 13211: Energy Effects 

I. National Technology Transfer 

Advancement Act 

J. Executive Order 12898: Federal Actions 

To Address Environmental Justice in 

Minority Populations and Low-Income 

Populations 

I. Overview 

A. Emergency Vehicle Provisions 

EPA is proposing amendments to its 

heavy-duty diesel engine programs that 

would specifically allow engine 

manufacturers to request to deploy 

specific emission controls or settings for 

new and in-use engines that are sold for 

use only in emergency vehicles. EPA is 

proposing these revisions to enable fire 

trucks and ambulances with heavy-duty 

diesel engines to perform missioncritical life- and property-saving work 

without risk of losing power, speed or 

torque due to abnormal conditions of 

the emission control systems. 

EPA’s current diesel engine 

requirements have spurred application 

of emission controls systems such as 

diesel particulate filters (commonly 

called soot filters or DPF’s) and other 

after-treatment systems on most new 

diesel vehicles, including emergency 

vehicles. Some control system designs 

and implementation strategies are more 

effective in other segments of the fleet 

than in emergency vehicles, especially 

given some emergency vehicles’ extreme 

duty cycles. By this action, EPA intends 

to help our nation’s emergency vehicles 

perform their missions; to better ensure 

public safety and welfare and the 

protection of lives and property. 

B. Diesel Exhaust Fluid Provisions 

EPA is proposing to amend its 

regulations for diesel engines to add 

provisions specifying emission-related 

maintenance and scheduled 

maintenance intervals for replenishment 

of consumable chemical reductant in 

connection with engines and vehicles 

that use selective catalytic reduction 

(SCR) technologies. This would apply to 

the use of SCR with model year (MY) 

2011 and later light-duty vehicles and 

nonroad compression ignition (NRCI) 

engines, and MY 2012 and later heavyduty vehicles and engines. 

Most manufacturers of diesel engines 

and vehicles subject to our current 

standards regulating oxides of nitrogen 

(NOX) have chosen to use a NOX

reduction technology known as 

selective catalytic reduction (SCR) in 

order to meet these requirements. SCR 

systems use a chemical reductant that 

usually contains urea and is known as 

diesel exhaust fluid (DEF). The DEF is 

injected into the exhaust gas and 

requires periodic replenishment by 

refilling the DEF tank. 

Given that SCR use is now common 

in the transportation sector and 

replenishment of DEF is necessary for 

SCR to be effective, it is appropriate to 

add DEF replenishment to the list of 

scheduled emission-related 

maintenance published in the Code of 

Federal Regulations (CFR), rather than 

rely on a case-by-case approval as is 

specified in the current regulations. 

This action would improve the clarity 

and transparency of EPA’s requirements 

for SCR systems. 

C. Nonroad Equipment Used 

Temporarily in Emergency Service 

EPA is proposing short-term relief 

from emission control system 

performance inducements for any 

nonroad compression ignition engine 

powered vehicles operating in 

temporary emergency service. This 

relief would address concerns about 

unusual circumstances where 

performance inducements could hinder 

equipment performance in emergency 

conditions, which are defined as 

conditions in which the functioning (or 

malfunctioning) of emission controls 

poses a significant risk to human life. 

We are proposing provisions for a shortterm emergency bypass of the normal 

emission controls, including 

inducement strategies, which could 

result in a loss of power of an engine; 

thus, allowing the equipment to 

temporarily perform emergency-related 

work. By this action, EPA would help 

our nation’s nonroad equipment 

perform temporary emergency service; 

to better ensure public safety and 

welfare and the protection of lives. 

II. Statutory Authority and Regulatory 

Background 

A. Statutory Authority 

Section 202(a)(1) of the Clean Air Act 

(CAA or the Act) directs EPA to 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34151 

1Control of Air Pollution from New Motor 

Vehicles: Heavy-Duty Engine and Vehicle 

Standards and Highway Diesel Fuel Sulfur Control 

Requirements (66 FR 5001). 

2Control of Emissions of Air Pollution from 

Nonroad Diesel Engines and Fuel (69 FR 38958). 

establish standards regulating the 

emission of any air pollutant from any 

class or classes of new motor vehicles or 

new motor vehicle engines that, in the 

Administrator’s judgment, causes or 

contributes to air pollution which may 

reasonably be anticipated to endanger 

public health or welfare. Such standards 

apply for the useful life of the vehicles 

or engines. Section 202(a)(3) requires 

that EPA set standards applicable to 

emissions of hydrocarbons, carbon 

monoxide, NOX and particulate matter 

(PM) from heavy-duty trucks that reflect 

the greatest degree of emission 

reduction achievable through the 

application of technology which we 

determine will be available for the 

model year to which the standards 

apply. We are to give appropriate 

consideration to cost, energy, and safety 

factors associated with the application 

of such technology. We may revise such 

technology-based standards, taking costs 

into account, on the basis of information 

concerning the effects of air pollution 

from heavy-duty vehicles or engines and 

other sources of mobile source related 

pollutants on the public health and 

welfare. 

Section 202(a)(4)(A) of the Act 

requires the Administrator to consider 

risks to public health, welfare or safety 

in determining whether an emission 

control device, system or element of 

design shall be used in a new motor 

vehicle or new motor vehicle engine. 

Under section 202(a)(4)(B), the 

Administrator shall consider available 

methods for reducing risk to public 

health, welfare or safety associated with 

use of such device, system or element of 

design, as well as the availability of 

other devices, systems or elements of 

design which may be used to conform 

to requirements prescribed by (this 

subchapter) without causing or 

contributing to such unreasonable risk. 

Section 206(a) of the Act requires EPA 

to test, or require to be tested in such 

manner as it deems appropriate, motor 

vehicles or motor vehicle engines 

submitted by a manufacturer to 

determine whether such vehicle or 

engine conforms to the regulations 

promulgated under section 202. Section 

206(d) provides that EPA shall by 

regulation establish methods and 

procedures for making tests under 

section 206. 

Section 213 of the Act gives EPA the 

authority to establish emissions 

standards for nonroad engines and 

vehicles (42 U.S.C. 7547). Sections 

213(a)(3) and (a)(4) authorize the 

Administrator to set standards and 

require EPA to give appropriate 

consideration to cost, lead time, noise, 

energy, and safety factors associated 

with the application of technology. 

Section 213(a)(4) authorizes the 

Administrator to establish standards to 

control emissions of pollutants (other 

than those covered by section 213(a)(3)) 

which ‘‘may reasonably be anticipated 

to endanger public health and welfare.’’ 

Section 213(d) requires the standards 

under section 213 to be subject to 

sections 206–209 of the Act and to be 

enforced in the same manner as 

standards prescribed under section 202 

of the Act. 

B. Background: 2007 and 2010 NOX and 

PM Standards 

(1) On-Highway Standards 

On January 18, 2001, EPA published 

a rule promulgating more stringent 

standards for NOX and PM for heavyduty highway engines (‘‘the heavy-duty 

highway rule’’).1 The 0.20 gram per 

brake-horsepower-hour (g/bhp-hr) NOX

standard in the heavy-duty highway 

rule first applied in MY 2007. However, 

because of phase-in flexibility 

provisions adopted in that rule and use 

of emission credits generated by 

manufacturers for early compliance, 

manufacturers were able to continue to 

produce engines with NOX emissions 

greater than 0.20 g/bhp-hr. The phase-in 

provisions ended after MY 2009 so that 

the 0.20 g/bhp-hr NOX standard was 

fully phased-in for model year 2010. 

Because of these changes that occurred 

in MY 2010, the 0.20 g/bhp-hr NOX

emission standard is often referred to as 

the 2010 NOX emission standard, even 

though it applied to engines as early as 

MY 2007. 

The heavy-duty highway rule adopted 

in 2001 also included a PM emissions 

standard for new heavy-duty diesel 

engines of 0.01 g/bhp-hr, effective for 

engines beginning with MY 2007. Due 

to the flexible nature of the phase-in 

schedule described above, 

manufacturers have had the opportunity 

to produce engines that met the PM 

standard while emitting higher levels of 

NOX. During the phase-in years, 

manufacturers of diesel engines 

generally produced engines that were 

tuned so the combustion process 

inherently emitted lower engine-out 

NOX while relying on PM aftertreatment to meet the PM standard. The 

principles of combustion chemistry 

dictate that conditions yielding lower 

engine-out NOX emissions generally 

result in higher engine-out PM 

emissions. This is what we call the 

NOX-PM trade-off. For many new lowNOX diesel engines today, engine-out 

PM emissions could be at or above the 

levels seen with the MY 2004 standards 

(0.1 g/bhp-hr). To meet today’s stringent 

PM standards, manufacturers rely on 

diesel particulate filter after-treatment to 

clean the exhaust. 

(2) Nonroad Standards 

EPA adopted similar technologyforcing standards for nonroad diesel 

engines on June 29, 2004.2 These are 

known as the Tier 4 standards. This 

program includes requirements that will 

generally involve the use of NOX aftertreatment for engines above 75 hp and 

PM after-treatment (likely soot filters) 

for engines above 25 hp. These 

standards phase in during the 2011 to 

2015 time frame. 

III. Direct Final Rule 

In addition to this notice of proposed 

rulemaking, EPA is also publishing a 

Direct Final Rule (DFR) addressing the 

emergency vehicle provisions described 

in Section IV of this document. We are 

doing this to expedite the regulatory 

process to allow engine and vehicle 

modifications to occur as soon as 

possible. However, if we receive 

relevant adverse comment on distinct 

elements of the emergency vehicle 

provisions in this proposal by July 27, 

2012, we will publish a timely 

withdrawal in the Federal Register 

indicating which provisions we are 

withdrawing. Any provisions of the DFR 

that are not withdrawn will become 

effective on August 7, 2012, 

notwithstanding adverse comment on 

any other provision. We will address all 

public comments in the final rule based 

on this proposed rule. 

As noted above, EPA is publishing the 

DFR to expedite the deployment of 

solutions that will best ensure the 

readiness of the nation’s emergency 

vehicles. We request that commenters 

identify in your comments any portions 

of the emergency vehicle proposed 

action described in Section IV below 

with which you agree and support as 

proposed, in addition to any comments 

regarding suggestions for improvement 

or provisions with which you disagree. 

In the case of a comment that is 

otherwise unclear whether it is adverse, 

EPA would interpret relevant comments 

calling for more flexibility or less 

restrictions for emergency vehicles as 

supportive of the direct final rule. In 

this way, the EPA will be able to adopt 

those elements of the DFR that are fully 

supported and most needed today, 

while considering and addressing any 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
34152 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

3 In this proposal, emergency vehicle is defined 

as a fire truck or an ambulance for on-highway 

applications, and for nonroad applications, we are 

defining emergency equipment as specialized 

vehicles to perform aircraft rescue and firefighting 

functions at airports, or, or wildland fire apparatus. 

See Section IV.C and proposed revisions at 40 CFR 

86.1803–01 and 40 CFR 1039.801. 

4Heavy-Duty Highway Final Rule, December 21, 

2000 Response to Comments, Section 3.2.1, 

‘‘Technical Feasibility of Engine/Vehicle 

Standards//Diesel Engine Exhaust Standards,’’ page 

3–58 to 3–60, available at http://www.epa.gov/otaq/ 

highway-diesel/regs/2007-heavy-duty-highway.htm. 

5Letter dated February 1, 2001 to C. Whitman, 

EPA Administrator from G. Miller, President, 

National Association of State Fire Marshalls. 

6See, for example, letter dated October 22, 2009, 

from Roger Lackore of the Fire Apparatus 

Manufacturers’ Association and Randy Hanson of 

the Ambulance Manufacturers Division, to Keisha 

Jennings of EPA. 

7See, for example, letter dated October 4, 2011 

from Congressman Filner to EPA Administrator 

Jackson, and letter dated October 14, 2011, from 

Director Cimini of the Southeast Association of Fire 

Chiefs to EPA Administrator Jackson. 

8See 49 U.S.C. 32902(e). 

9Final Rule: Control of Emissions of Air Pollution 

from Locomotives and Marine CompressionIgnition Engines Less Than 30 Liters per Cylinder, 

73 FR 25098, May 6, 2008, and republished to 

correct typographical errors on June 30, 2008, 73 FR 

37096. 

10Final Rule: Phase 2 Emission Standards for 

New Nonroad Spark-Ignition Nonhandheld Engines 

at or Below 19 Kilowatts, 64 FR 15208, March 30, 

1999. 

adverse comments received on the 

proposed rule, in the course of 

developing the final rule. 

Note that Docket Number EPA–HQ– 

OAR–2011–1032 is being used for both 

the DFR and this Notice of Proposed 

Rulemaking (NPRM). 

IV. Emergency Vehicle Provisions 

A. Background on Regulation of 

Emergency Vehicles 

Typically, the engines powering our 

nation’s emergency vehicles belong to 

the same certified engine families as 

engines that are installed in similarly 

sized vehicles sold for other public and 

private uses.3 Historically, engine and 

vehicle manufacturers have sought EPA 

certification for broad engine families 

and vehicle test groups that are defined 

by similar emissions and performance 

characteristics. Engine families typically 

only consider the type of vehicle in 

which the engine is intended to be 

installed to the extent that it fits into a 

broad vehicle weight class and, to a 

lesser extent, the vehicle’s intended 

duty cycle (i.e. urban or highway). 

Because of the above-described 

manufacturing practices and the narrow 

CAA authority for any exemptions, EPA 

has historically regulated engines for 

emergency vehicles, including 

ambulances as well as police vehicles 

and fire-fighting apparatus, in the same 

manner as other engines. 

In the public comments received on 

the proposed heavy-duty highway rule, 

EPA received some comments about 

DPF technologies and regeneration 

cycles on heavy-duty trucks, including 

one comment that expressed concerns 

that the systems may not be failsafe.4

However, none of the comments 

specifically raised technical feasibility 

with respect to emergency vehicles, and 

EPA’s response was based on the best 

information available at the time. After 

publishing the final rule requiring 

heavy-duty highway engines to meet 

performance standards that compelled 

technologies such as DPF’s, EPA 

received a letter from the National 

Association of State Fire Marshals, 

requesting some provision for public 

safety in implementing this new rule, 

considering that fire departments across 

the nation have trouble covering basic 

costs and may not have funds for more 

expensive trucks.5 This letter did not 

raise any technical feasibility issues, 

and EPA did not see a need to take 

action. 

More recently EPA has received 

letters from fire apparatus 

manufacturers and ambulance 

companies requesting relief from power 

or speed inducements related to low 

levels of DEF for SCR systems on 

emergency vehicles.6 Power and speed 

reduction inducements were new on 

vehicles equipped with SCR. These 

were not specifically mandated by EPA 

but designed by manufacturers to occur 

if DEF levels became low, to induce 

operators of the vehicles to perform the 

required emission-related maintenance 

in use. More discussion on this, 

including why the emergency response 

community requested relief and what 

action EPA took, is found below in 

Section IV.C(3). 

Recently, beginning in October 2011, 

EPA received a series of comment letters 

from fire chiefs and other interested 

stakeholders, requesting regulatory 

action to relieve emergency vehicles 

from the burden of complying with the 

2007 PM standards.7 EPA promptly 

opened a dialogue with the fire chiefs 

and engine manufacturers to understand 

the issues. Power and speed reductions 

were occurring on some vehicles with 

soot filters but without SCR systems, in 

part related to engine protection 

measures designed by manufacturers. 

Essentially, these soot filters are 

supposed to be self-cleaning by 

periodically burning off accumulated 

soot during normal vehicle use. The 

cleaning process is called regeneration, 

and when this doesn’t work as designed, 

the filter gradually gets more clogged, 

which can lead to engine problems. EPA 

has determined that while other 

pathways are available for resolving 

some issues related to soot filters on 

emergency vehicles, there remains a 

public safety issue related to design of 

engines and emission control systems 

on emergency vehicles that should be 

addressed through this rulemaking. 

More discussion of this, including why 

relief was requested and what other 

actions can be taken in addition to EPA 

regulation, is found below in Sections 

IV.C and IV.D. 

B. Current Provisions for Other 

Emergency Vehicles and Engines 

On December 1, 2011, in a proposed 

rule issued jointly with the National 

Highway Traffic Safety Administration 

(NHTSA), EPA proposed to exclude 

light-duty emergency and police 

vehicles from all phases of greenhouse 

gas (GHG) emissions standards, in part 

due to concerns related to technical 

feasibility, and in part to harmonize 

with NHTSA’s program. Consistent with 

authority under the Energy Policy and 

Conservation Act, NHTSA’s corporate 

average fuel economy program already 

provides manufacturers with the option 

to exclude emergency vehicles.8 The 

agencies are considering and responding 

to comments on this proposal, and plan 

to finalize this rule in summer 2012. 

In addition to the above proposed 

exemption for on-highway engines from 

GHG standards, EPA has provided 

limited regulatory relief for other types 

of emergency-use engines. First, EPA’s 

May 6, 2008 final rule adopting Tier 3 

and Tier 4 standards for marine diesel 

engines allows for emergency and 

rescue vessels to meet an earlier, less 

stringent tier of standards under 40 CFR 

parts 89, 94 and 1042.9 We adopted 

these provisions to avoid compromising 

engine performance during emergency 

operation, and to ensure that more 

stringent emission standards did not 

cause a situation where there were no 

certified engines available for 

emergency vessels. Such engines are not 

subject to the Tier 4 standards, which 

generally involve selective catalytic 

reduction and diesel particulate filters. 

The regulations also allow for meeting 

less stringent standard if there are no 

suitable engines that are certified to the 

current standards. 

EPA also adopted limited exemption 

provisions for emergency rescue 

equipment for small spark-ignition 

nonroad engines in 1999.10 Under this 

provision, equipment manufacturers 

needed to demonstrate that no engine 

models certified to current emission 

standards were available to power the 

emergency rescue equipment. We 


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Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34153 

11Final Rule: Control of Emissions from Nonroad 

Spark-Ignition Engines and Equipment, 73 FR 

59034, October 8, 2008. 

12Final Regulatory Impact Analysis for the ‘‘2007 

Heavy-Duty Highway Rule,’’ EPA420–R–00–026, 

December 2000. Chapter III, Emissions Standards 

Feasibility, is available at http://www.epa.gov/otaq/ 

highway-diesel/regs/ria-iii.pdf. 

13Final Regulatory Impact Analysis for ‘‘Control 

of Emissions from Nonroad Diesel Engines,’’ 

EPA420–R–04–007, May 2004. Chapter 4, 

Technologies and Test Procedures for LowEmission Engines, is available http://www.epa.gov/ 

nonroad-diesel/2004fr/420r04007e.pdf. 

14See Final RIA Chapter III, Note 12, above. 

recently moved this provision to 40 CFR 

part 1054 and included a variety of 

elements to clarify and improve 

oversight of the exemption in a later 

final rule.11 These elements include a 

requirement that the engines meet the 

most stringent standards feasible (but 

less than the current standards for 

certification) and annual reporting to 

EPA on the availability of compliant 

engines that meet the needs of other 

emergency equipment using such 

engines. 

In these rules, EPA recognized that 

equipment and vessels designed and 

purpose-built exclusively for use in 

emergency equipment have demanding 

performance specifications and in some 

cases extreme duty cycles. The marine 

diesel provisions also recognize that 

engines certified to the latest emissions 

standards requiring emissions aftertreatment may create some interference 

with engine performance or 

effectiveness that may be needed in 

emergency circumstances, when 

installed in some emergency equipment 

or vessels. 

While these provisions do offer 

limited relief from the latest round of 

emissions standards for these engines, 

there is a general requirement to use 

engines meeting the most stringent 

emission standards as practical. There 

are also additional administrative 

responsibilities related to engine 

labeling, periodic reporting to EPA, and 

recordkeeping. These provisions in 

some cases also expire if compliant 

engines become available that can 

practically be used to provide power for 

the equipment in question. 

Furthermore, these limited exemption 

provisions are only applicable to newly 

certified engines. The regulations do not 

apply these provisions to in-use engines 

that are certified and deployed in 

emergency equipment. 

C. Why is EPA taking this action? 

EPA is proposing to amend its 

regulations to facilitate engine 

manufacturers’ design and 

implementation of reliable and robust 

emission control systems with 

regeneration strategies and other 

features that do not interfere with the 

mission of emergency vehicles. Through 

the comments and letters we have 

received, as well as our own outreach 

and data-gathering efforts, we have 

learned that some emission control 

systems on fire trucks and ambulances 

today, in particular, certain applications 

using diesel particulate filters, are 

requiring an unexpected amount of 

operator interventions, and there are 

currently a nontrivial number of 

emergency vehicles that are 

electronically programmed to cut power 

or speed—even while responding to an 

emergency—when certain operational 

parameters are exceeded in relation to 

the emission control system. As we 

understand it, the experiences of 

operators are mixed, with some not 

reporting any problems and some 

reporting problems that raise public 

safety and welfare concerns. 

EPA’s standards are performancebased, and reflect the greatest degree of 

emission reduction achievable, 

according to CAA sections 202(a)(3) and 

213(a)(3). Our on-highway and nonroad 

PM standards do not specify the type of 

diesel particulate filter for 

manufacturers to use, nor do they even 

mandate the use of such a filter. Our 

analysis of the feasibility of the 2007 onhighway PM standard is presented in 

Chapter III of the final Regulatory 

Impact Analysis (RIA) for that rule.12

Our analysis of the feasibility of the Tier 

4 nonroad compression ignition engine 

standards that will be phasing in 

through 2015 is presented in Chapter 4 

of that rule’s final RIA.13 For most 

nonroad engines, these standards are 

similar in stringency to the 2007 onhighway heavy-duty engine and vehicle 

standards. As described below in 

Section VII, these two rules are 

providing billions of dollars of annual 

health benefits by virtually eliminating 

harmful PM emissions from the 

regulated engines. Even so, EPA is 

required by sections 202(a)(4)(B) and 

213(c) of the Act to, among other things, 

consider methods for reducing risk to 

public safety and welfare associated 

with the use of emission control devices 

or systems. 

Based on the information available to 

us, we have concluded that there is an 

indirect risk to public safety and welfare 

associated with some examples of 

emission control systems when they are 

deployed on emergency vehicles that 

experience extreme duty cycles. This 

indirect risk is related to the readiness 

of emergency vehicles and the risk that 

they may not be able to respond during 

emergencies with the full power, torque, 

or speed that the engine is designed to 

provide. While this risk is not inherent 

to the requirement to reduce emissions 

or to the use of diesel particulate filters 

on emergency vehicles, EPA believes it 

is appropriate to ensure that emergency 

vehicles can perform their emergency 

missions without the chance of such 

consequences. 

EPA’s current rules already provide 

the opportunity for manufacturers to 

address many issues through 

applications for certification of new 

engines and new vehicles. There is also 

currently a mechanism for 

manufacturers to deploy field 

modifications to the in-use fleet, 

including those that are substantially 

similar to approved upgrades for new 

vehicles, as well as those that apply 

only to vehicles that are no longer in 

production. As manufacturers become 

aware of the need for upgrades or 

enhancements, this process occurs 

within the new and in-use fleet with 

various degrees of application. While 

that process is occurring today, EPA 

views this issue as serious enough that 

we would be remiss if we did not act to 

ensure that our regulations clearly offer 

the needed flexibilities for emergency 

vehicles. 

(1) How does a DPF work? 

To explain more fully the issues that 

we are addressing with this action, and 

hence why we are taking this action, we 

are providing here some background 

information on diesel particulate filters 

and the process of DPF regeneration. 

DPF’s are exhaust after-treatment 

devices that significantly reduce 

emissions from diesel-fueled vehicles 

and equipment. DPF’s physically trap 

PM and remove it from the exhaust 

stream. Figure IV–1 depicts a schematic 

of a wall-flow monolith style filter, with 

the black arrows indicating exhaust gas 

laden with particles, and the gray 

arrows indicating filtered exhaust gas. 

This style of filter is the most common 

in today’s heavy-duty diesel engines, 

and has very high rates of filtration, in 

excess of 95 percent.14


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34154 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

15EPA’s regulations at 40 CFR 86.004–25(b)(4) for 

heavy-duty diesel engine maintenance specify a 

minimum interval for DPF ash cleanout from 

100,000 to 150,000 mi. Many manufacturers design 

DPF systems with longer maintenance intervals. 

16See http://www.arb.ca.gov/diesel/tru/ 

documents/ashguide.pdf. 

17See memo dated May 4, 2012, ‘‘Diesel 

Particulate Filter Regeneration,’’ Docket ID EPA– 

HQ–OAR–2011–1032. 

To be successful, these devices 

generally must be able to accomplish 

two things: Collect PM and clean away 

accumulated PM. There are two main 

types of PM that can accumulate: 

Combustible and non-combustible, and 

two very different types of cleaning 

methods: Regeneration and ash 

cleaning. Regeneration occurs relatively 

frequently, and is designed to complete 

the combustion (oxidation) of the 

trapped combustible PM components, 

releasing them to the exhaust as gasphase compounds (mostly H2O and 

CO2). In contrast to the PM that can be 

oxidized and carried out the tailpipe as 

gases, the non-combustible PM such as 

metallic ash cannot be destroyed 

through regeneration and will always 

remain inside a DPF. To clean ash from 

a DPF, the filter unit is removed from 

the vehicle and professionally cleaned 

with a special machine. Fortunately, 

there is very little ash formation from 

modern diesels so ash cleaning and ash 

disposal occurs very infrequently, 

generally with at least 150,000 mile 

service intervals, and the mass of 

accumulated ash is generally small (a 

few teaspoons).15 16 This distinction is 

made here because the ash cleaning 

process is not a source of concern that 

has given rise to this EPA action. The 

infrequent cleaning of noncombustible 

materials from DPF’s is not part of the 

scope of this action. 

Regeneration, however, is a type of 

routine DPF cleaning that must occur 

regularly, and for which EPA does not 

specify a minimum interval in its 

regulations, in contrast to the ash 

cleaning process. At its very essence, 

regeneration involves burning off the 

accumulated soot. Since this burning 

can involve extra heat and/or oxygen or 

oxygen-containing compounds, this 

must be done carefully and safely to 

avoid uncontrolled burns. The 

discussion below in Section IV.C.(1)(b) 

describes the three types of routine DPF 

regeneration: Passive regeneration, 

automatic active regeneration, and 

manual (parked) active regeneration. A 

more detailed discussion is provided in 

a memorandum to the docket.17 Before 

discussing the ways that manufacturers 

achieve regeneration, though, first we 

discuss the reason why it is needed at 

all. 

(a) Failure of a DPF 

When the style of filter installed on a 

diesel vehicle is the wall-flow type that 

is predominant in the market today, it 

physically traps so much of the PM that 

the particles accumulate on the inside of 

the filter and if not burned off, this PM 

can over time block the passages 

through the filtering media, making it 

more restrictive to exhaust flow. This is 

commonly referred to as ‘‘trap 

plugging.’’ Some other styles of filter, 

such as flow-through DPF’s, are less 

prone to plugging, but do not generally 

reduce the PM emission rate sufficiently 

to meet today’s stringent PM standard. 

Any time something gets in the way of 

free flowing air through an engine, it 

creates what we call ‘‘exhaust 

backpressure.’’ Even a clean, new DPF 

generates a small amount of exhaust 

backpressure due to the porous walls 

through which all of the exhaust flows. 

Engines can tolerate a certain range of 

exhaust backpressure. When an increase 

in this backpressure, or resistance, is 

detected, engines can compensate to a 

point. An increase in exhaust 

backpressure from a DPF trapping more 

and more PM represents increased work 

demanded from the engine to force the 

exhaust gas through the increasingly 

restrictive DPF. However, unless the 

DPF is frequently cleansed of the 

trapped PM, this increased work 


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demand can lead to reductions in 

engine performance and increases in 

fuel consumption. This loss in 

performance may be noticed by the 

vehicle operator in terms of poor 

acceleration and generally poor 

drivability of the vehicle. 

If a DPF is not regenerated and it 

becomes plugged, there is a risk of two 

types of failure. The degree of this risk 

and which consequence may be 

experienced will depend on the engine 

and emission control system design. 

One consequence is that the lack of air 

flowing through an engine will cause an 

engine to shut down because it can no 

longer compensate for the extra work 

being demanded of it. The other is a risk 

of catastrophic DPF failure when 

excessive amounts of trapped PM begin 

to oxidize at high temperatures (i.e., 

DPF regeneration temperatures above 

1,000 °C) leading to a ‘‘runaway’’ 

combustion of the PM within the DPF. 

This can cause temperatures in the filter 

media to increase beyond its physical 

tolerance, possibly creating high 

thermal stresses where the DPF 

materials could crack or melt. This is an 

unsafe condition, presenting physical 

danger to occupants as well as to objects 

and persons near the vehicle. Further, 

catastrophic failure can allow 

significant amounts of the diesel PM to 

pass through the DPF without being 

captured. That is, the DPF is destroyed 

and PM emission control is lost. For all 

these reasons, most manufacturers 

generally design their emission control 

systems to prevent uncontrolled 

shutdown or runaway DPF regeneration 

by programming the engine’s electronic 

control module (ECM) to limit 

maximum engine speed, torque and/or 

power when excessive backpressures 

are detected. This mode of engine 

operation at reduced performance may 

allow a vehicle to ‘‘limp home’’ to 

receive service. In extreme cases the 

ECM may command the engine to shut 

down to prevent a catastrophic failure. 

(b) Types of Regeneration 

There are three types of routine DPF 

regeneration. Passive regeneration refers 

to methods that rely strictly on the 

temperatures and constituents normally 

available in the vehicle’s exhaust to 

oxidize PM from a DPF in a given 

vehicle application. Passive 

regeneration is an automatic process 

that occurs without the intervention of 

an engine’s on-board diagnostic and 

control systems, and often without any 

operator notice or knowledge. Passive 

regeneration is often a continuous 

process, because of which, it is 

sometimes referred to as continuous 

regeneration. In a vehicle whose normal 

operation does not generate 

temperatures needed for passive DPF 

regeneration, the system needs a little 

help to clean itself. This process is 

called active regeneration, and 

supplemental heat inputs to the exhaust 

are provided to initiate soot oxidation. 

There are two types of active 

regeneration: Those that may occur 

automatically either while the vehicle is 

in motion, while idling, or while 

powering an auxiliary device such as a 

pump or ladder (power take-off (PTO) 

mode), and those that must be driverinitiated and occur only while the 

vehicle is stationary and out-of-service. 

Vehicles with automatic active 

regeneration systems require operators 

to be alert to dashboard lamps and 

indicators. Written instructions are 

provided to operators to explain what 

each lamp means (such as high 

temperatures or need for regeneration) 

and what action is called for (such as 

driving at highway speeds or initiating 

a manual active regeneration). Because 

EPA emissions standards are 

performance based; and therefore, do 

not dictate any required emission 

control system technologies or 

configurations, each manufacturer has 

the discretion to program the timing and 

sequence of lamps as needed to inform 

drivers of the condition of the emission 

control system. As noted above, it is not 

uncommon in today’s heavy-duty fleet 

for an engine’s ECM to limit its 

maximum speed, torque or power when 

a plugging DPF is detected. These 

engine and emission control system 

protection measures can alert drivers to 

the need to change driving conditions to 

facilitate automatic active regeneration 

or to make plans to allow for a manual 

active regeneration. 

A manual active regeneration allows 

the engine’s ECM to increase engine 

speed and exhaust temperature to a 

greater extent than what is typically 

allowed during an automatic active 

regeneration. Because the ECM takes 

full control of an engine during a 

manual active regeneration, the vehicle 

must remain parked and not used for 

other purposes, such as pumping water 

in PTO mode. Some manual active 

regenerations may require towing the 

vehicle to a special service center, and 

may occur while the DPF is on the 

vehicle, or offline with the DPF 

removed from the vehicle. In such cases, 

if a spare DPF is not available, the 

vehicle could be out of service 

overnight. If a driver disregards such 

warnings, the risk of uncontrolled 

engine shutdown or a catastrophic DPF 

failure may increase. EPA encourages 

the design of robust systems calling for 

minimal driver interventions, while 

providing drivers with clear and early 

indicators before any interventions are 

needed. EPA also encourages accurate 

and thorough operator training to ensure 

that the correct remedial action is taken 

at the earliest available time. 

Actively regenerating DPF systems 

typically require sufficient air flow, 

temperature and soot accumulation 

before an automatic active regeneration 

will be requested by the engine’s ECM. 

As mentioned above, this may occur 

either while the vehicle is in motion or 

parked, if pre-set engine operating 

conditions are met (such as speed and 

temperature). When the engine’s ECM 

signals the initiation of an automatic 

active regeneration and the extra heat is 

generated, an ideal DPF system 

accomplishes this as a transparent 

process, with no effects perceivable by 

the driver. 

A variety of manufacturer approaches 

can be taken to produce the 

supplemental heat needed for active 

regeneration. Diesel engines of MY 2007 

or newer often incorporate one or more 

of the following approaches: 

• On-board electrical heaters 

upstream of the filter. 

• Air-intake throttling in one or more 

of the engine cylinders. When 

necessary, this device would limit the 

amount of air entering the engine, 

raising the exhaust temperature and 

facilitating regeneration. 

• Exhaust brake activation. When 

necessary, this device would limit the 

amount of exhaust exiting the engine, 

raising the exhaust temperature and 

facilitating regeneration. 

• Engine speed increases. This 

approach is sometimes used in 

combination with the other approaches 

to deliver more heat to the filter to 

facilitate regeneration. 

• Post top-dead-center (TDC) fuel 

injection. Injecting small amounts of 

fuel in the cylinders of a diesel engine 

after pistons have reached TDC 

introduces a small amount of unburned 

fuel in the engine’s exhaust gases. This 

unburned fuel can then be oxidized over 

an oxidation catalyst upstream of the 

filter or oxidized over a catalyzed 

particulate filter to combust 

accumulated particulate matter. 

• Post injection of diesel fuel in the 

exhaust upstream of an oxidation 

catalyst and/or catalyzed particulate 

filter. This method serves to generate 

heat used to combust accumulated 

particulates by oxidizing fuel across a 

catalyst present on the filter or on an 

oxidation catalyst upstream of the filter 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
34156 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

18MECA Diesel Particulate Filter Maintenance: 

Current Practices and Experience (June 2005) 

http://www.meca.org/galleries/default-file/ 

Filter_Maintenance_White_Paper_605_final.pdf. 

• On-board fuel burners upstream of 

the filter.18

These are presented here merely as 

examples, and are by no means a 

complete list of the strategies available 

to manufacturers when designing 

engines that use automatic active DPF 

regeneration, though not all may be 

applicable to all engines. A common 

approach that gets a lot of consumer 

attention is the use of fuel burners or 

fuel injection strategies. This approach 

is often called ‘‘dosing.’’ Vehicle owners 

may notice an increase in fuel 

consumption when driving a vehicle 

that relies heavily on fuel dosing for its 

automatic active regenerations. In this 

case, when an engine’s ECM gives the 

signal, the doser injects a metered 

amount of diesel fuel into the exhaust 

flow (or cylinders), which reacts with 

the DPF catalyst to raise the temperature 

to a point that enables regeneration. 

EPA does not have information about 

which manufacturers employ this 

technique or the number or types of 

vehicles with engines that use fuel 

dosing as part of the active regeneration 

strategy. Estimates of the additional fuel 

use by a vehicle whose DPF 

regeneration system employs fuel 

dosing are described below in Section 

VII.B. This is also mentioned here 

because one of the possible outcomes of 

this EPA action is that some 

manufacturers may alter their strategies 

for automatic active regenerations on 

emergency vehicles, which may have a 

modest effect on supplemental fuel use 

due to dosing. Further discussion of this 

is provided below in Section VII. 

(2) Why are emergency vehicles having 

problems with DPF regeneration? 

At the time of promulgation of the 

heavy-duty highway rule, EPA and the 

engine manufacturers expected the 

2007-compliant engine emission control 

systems would be integrated with 

advanced engine controls to ensure DPF 

regeneration under all vehicle operating 

conditions and environments. While 

this is widely true today, the experience 

of the rule implementation thus far 

indicates there are still some exceptions. 

Although EPA is aware of a relatively 

small number of emergency vehicles 

that are experiencing problems with 

DPF regeneration, of those that are 

having problems, most of the problems 

can be related to the vehicle’s duty 

cycle, the ambient conditions, and/or 

the engine’s combustion characteristics. 

A vehicle’s duty cycle means how it is 

driven, including its speeds, loads, and 

distances, as well as time out of service 

and time spent idling. A vehicle’s duty 

cycle can vary by the demographic of 

the service area, including whether the 

vehicle responds to emergencies in a 

rural or urban community, and whether 

it drives over flat or hilly terrain. 

Because DPF regeneration requires heat 

and oxygen (basic ingredients for 

combustion), the success of DPF 

regeneration strategies can also be 

influenced by ambient conditions such 

as extreme cold winter temperatures 

and whether the vehicle operates near 

sea level or at a high elevation. The 

engine combustion and exhaust 

characteristics can influence the success 

of a DPF regeneration strategy since 

parameters such as engine-out NOX and 

PM emission levels can influence how 

easily the soot can be oxidized, and how 

much soot needs to be oxidized and 

how often. 

Both the engine’s duty cycle and the 

overall control strategy of the engine’s 

emission control system play a large 

role in the success of integrating a DPF 

with an engine to control PM emissions. 

In this section we provide additional 

discussion of how engine combustion 

characteristics and vehicle duty cycle 

can lead to DPF regeneration problems 

on emergency vehicles. In Section IV.E, 

below, we discuss our proposed 

regulatory action to address these 

issues. While our proposed approach 

specifically targets engine combustion 

characteristics and emission control 

system design, we encourage emergency 

vehicle owners to inquire with their 

dealers and manufacturers regarding 

suitable vehicle and engine options that 

are appropriate for their duty cycle as 

well as their demographic and 

geographic location. 

(a) Engine Combustion Characteristics 

Engine combustion characteristics can 

be designed to enable continuous 

passive regeneration or to rely heavily 

on automatic active regeneration. As 

mentioned above, regeneration is a 

combustion process, burning off the 

accumulated PM or soot. The PM is 

created because the initial combustion 

process in the engine was imperfect. To 

completely convert all fuel to CO2 and 

water, the combustion process needs 

more heat and oxygen. Both of these 

things create NOX because nitrogen (N2) 

is naturally present in the air and 

readily oxidizes at high temperatures. 

Thus there is a NOX-PM trade-off of 

most diesel combustion processes 

(homogeneous charge compression 

ignition being an exception) where 

lower combustion temperatures help 

control NOX but create more PM, and 

higher temperatures that destroy PM (or 

prevent it from being created) can 

generate more NOX. 

In an engine with a DPF system, 

combustion settings, or calibrations that 

enable continuous passive regeneration, 

tend to be those with higher engine-out 

NOX and lower engine-out PM, partly 

because of the higher temperatures that 

create the NOX, partly because of the 

NOX itself that can act as an oxidizer (to 

burn off soot), and partly because of the 

lighter soot loading rate. In contrast, 

engine calibrations that may lead to a 

heavy reliance on automatic active 

regeneration tend to be those with lower 

engine-out NOX and higher engine-out 

PM, partly because of the lower 

temperatures, partly because of a lack of 

helpful NOX, and partly because of a 

heavier soot loading rate. Note that 

‘‘engine-out’’ means emissions upstream 

of any after-treatment cleaning devices 

such as DPF or SCR. An example of a 

DPF system that may rely almost 

exclusively on active regeneration to 

maintain a clean PM filter, from an 

engine calibration perspective, would be 

an engine using advanced exhaust gas 

recirculation, because it would have 

very low engine-out NOX and relatively 

high engine-out PM. An example of a 

DPF system that may rarely experience 

automatic active regeneration (and 

frequently passively regenerate), from 

an engine calibration perspective, 

would be an engine using SCR to 

control NOX, because it could have 

comparatively high engine-out NOX and 

relatively low engine-out PM. The SCR 

after-treatment would then reduce the 

high engine-out NOX to provide very 

low tailpipe NOX. 

Thus it is important to note that this 

NOX-PM trade-off is a critical design 

parameter when developing an engine 

that will be successfully integrated with 

a DPF-equipped emission control 

system. To date, all of the concerns 

expressed to EPA regarding emergency 

vehicles with DPF regeneration issues 

have been for vehicles that do not 

employ SCR technology, and thus may 

have higher engine-out PM. The 

differences in engine combustion 

characteristics of the MY 2007 vehicles 

compared to those of the majority of MY 

2010+ vehicles support the concept that 

the emergency vehicle fleet may 

experience fewer DPF regeneration 

troubles as it migrates to engines that 

use after-treatment to meet EPA’s 2010 

NOX standards. Such a trend may 

indicate that some engine manufacturers 

may see a greater need to address in-use 

emergency vehicles than new vehicles. 


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19Fire Apparatus Manufacturer’s Association, 

Fire Apparatus Duty Cycle White Paper, August 

2004, available at http://www.deepriverct.us/ 

firehousestudy/reports/Apparatus-Duty-Cycle.pdf. 

(b) Duty Cycles 

As noted above, the duty cycle of a 

vehicle is one of the factors that 

influences how often the DPF 

regenerates passively or actively. It is 

important to note that all DPF systems 

with active regeneration components 

also have the capability to passively 

oxidize soot accumulated on the filter, 

though some of the above-described 

factors may inhibit successful passive 

regeneration. Operation at highway 

speeds and high engine loads (high load 

means demanding more work from the 

engine, such as accelerating, driving 

uphill or carrying heavy cargo) typically 

leads to successful passive regeneration 

of a DPF. An example from a duty-cycle 

perspective of a vehicle that frequently 

experiences automatic passive 

regeneration would be a long-haul 

tractor-trailer. There is also often a 

threshold of speed or load that is 

required for automatic active 

regeneration strategies as well, though 

not as great as for passive regeneration— 

often at least 5 miles/hour or parked 

with a PTO engaged. In some vehicles, 

passive regeneration occurs so rarely 

that a DPF system relies almost 

exclusively on active regenerations to 

maintain a clean PM filter. An example 

of this from a duty-cycle perspective 

would be a vehicle that operates at idle, 

low speed and low load over most of its 

duty cycle. Many emergency vehicles 

fall into this category. 

It is possible to collect duty cycle data 

from trucks by extracting information 

that is broadcast by the engine’s ECM. 

ECM’s broadcast information such as 

engine speed, load, temperature, DPF 

backpressure, and many other 

parameters relevant to engine operation. 

In 2004 the Fire Apparatus 

Manufacturers Association conducted a 

data-collection project, downloading 

logged data from emergency vehicles in 

use across the United States, to 

document duty cycles and engine 

conditions typically experienced in the 

emergency fleet, including pumpers, 

aerials, and rescue vehicles in urban, 

suburban and rural communities.19 The 

2004 FAMA data set includes 26 service 

months of data from 51 pumper trucks, 

31 service months of data from 21 aerial 

trucks, and 14 service months of data 

from 4 rescue vehicles. Overall, the data 

reveal that emergency vehicles in urban 

centers log more hours than vehicles in 

suburban or rural areas, with the urban 

and suburban vehicles logging over five 

and four times the average rural engine 

hours, respectively, on an annual basis. 

This demographic data could be helpful 

to fleet managers who wish to 

understand why they have or have not 

experienced certain troubles with their 

vehicles. The data also indicate that 

vehicles with PTO capability (pumpers 

and aerials) operate in PTO mode on 

average about 10 percent of their 

operating time. Further, the data 

indicate the vast majority of emergency 

fleet operation is at loads below 10 

percent of maximum capacity and 

engine speeds below 1,000 rpm. Data of 

this type could be helpful to engine 

manufacturers who may wish to assure 

that their emission control system 

designs will be successful for a given 

application. For the vehicles from 

which operating data were collected, 

FAMA determined an average engine 

load using the total horsepower, percent 

load, and percent time at load. Table 

IV–1 presents a summary of the engine 

load data compiled in FAMA’s study. 

Table IV–2 presents operating data by 

both vehicle type and demographic, and 

Table IV–3 presents an overview of the 

data by vehicle type. 

TABLE IV–1—FAMA ENGINE LOAD

DATA

Apparatus 

type 

Capacity 

range in 

study 

Population average percent 

running load 

Pumper ....... 315–500 hp .. 18 

Aerial .......... 170–500 hp .. 30 

Rescue ....... 350–500 hp .. 20 

TABLE IV–2—FAMA DUTY CYCLE DATA BY DEMOGRAPHIC

Service area Operating condition Pumper Aerial Rescue Service area 

average 

Rural ................. Engine Hours (Avg Annual) .............................................. 301 204 301 295 

PTO Hours (Avg Annual) ................................................. 70 63 ........................ ........................

Low Speed (% Time < 1,000 RPM) ................................. 63 73 51 a62 

Medium Speed (% Time 1,000 < RPM < 1,800) ............. 27 19 42 a29 

High Speed (% Time > 1,800 RPM) ................................ 11 9 7 a9 

Low Load (% Time < 10%) .............................................. 61 83 59 a68 

Medium Load (% Time 10% < Load < 90%) ................... 36 11 39 a29 

High Load (% Time > 90%) .............................................. 3 6 2 a4 

Suburban .......... Engine Hours (Avg Annual) .............................................. 1364 1133 367 1272 

PTO Hours (Avg Annual) ................................................. 168 b123 ........................ ........................

Low Speed (% Time < 1,000 RPM) ................................. 71 68 77 a72 

Medium Speed (% Time 1,000 < RPM < 1,800) ............. 23 27 17 a22 

High Speed (% Time > 1,800 RPM) ................................ 6 5 7 a6 

Low Load (% Time < 10%) .............................................. 54 37 78 a56 

Medium Load (% Time 10% < Load < 90%) ................... 44 58 22 a41 

High Load (% Time > 90%) .............................................. 3 5 0 a3 

Urban ................ Engine Hours (Avg Annual) .............................................. 1107 2379 1686 1681 

PTO Hours (Avg Annual) ................................................. 93 b213 ........................ ........................

Low Speed (% Time < 1,000 RPM) ................................. 62 73 57 a64 

Medium Speed (% Time 1,000 < RPM < 1,800) ............. 32 22 32 a29 

High Speed (% Time > 1,800 RPM) ................................ 5 5 11 a7 

Low Load (% Time < 10%) .............................................. 73 53 44 a57 

Medium Load (% Time 10% < Load < 90%) ................... 24 42 51 a39 

High Load (% Time > 90%) .............................................. 3 5 5 a4 

Notes: 

aStraight average by EPA from summary results. Other values in this table are weighted averages compiled by FAMA using individual vehicle 

data. b Includes both pumping and aerial operating hours. 


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34158 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

TABLE IV–3—FAMA DUTY CYCLE DATA BY VEHICLE TYPE

Operating condition Pumper class 

average 

Aerial class 

average 

Rescue class 

average Fleet average 

Engine Hours (Avg Annual) ............................................................................. a 924 a 1239 a 785 1244 

PTO Hours (Avg Annual) ................................................................................. b 117 ........................ ........................

Low Speed (% Time < 1,000 RPM) ................................................................ 66 71 61 67 

Medium Speed (% Time 1,000 < RPM < 1,800) ............................................. 27 23 30 26 

High Speed (% Time > 1,800 RPM) ............................................................... 7 5 9 7 

Low Load (% Time < 10%) .............................................................................. 62 50 56 58 

Medium Load (% Time 10% < Load < 90%) ................................................... 35 45 41 38 

High Load (% Time > 90%) ............................................................................. 3 5 3 3 

Notes: 

aStraight average by EPA from summary results. Other values in this table are weighted averages compiled by FAMA using individual vehicle 

data. b Includes only pumping hours. Aerial operating hours averaged 69 hours per year. 

We can see from this study that 

engines on emergency vehicles across 

the country are commonly operated over 

duty cycles that offer very limited 

opportunities to regenerate DPF’s. It is 

also important to note that emergency 

vehicles do not typically get deployed 

on planned duty schedules with 

predictable blocks of garage time for 

servicing or maintenance. While some 

other types of vocational vehicles may 

have duty cycles with many 

characteristics similar to those shown 

above, emergency vehicles are unique in 

their need to be ready to deploy at any 

moment for the purpose of protecting 

public safety and welfare by saving 

human lives that may be in immediate 

danger. 

When trucks with an engine-driven 

PTO are working in a stationary PTO 

mode, some engines achieve the 

conditions to enable an automatic active 

regeneration during this time. While 

this is normally designed to be a 

transparent process, in practice some 

effects of this type of regeneration have 

been noticed by operators. EPA has 

received information from fire chiefs 

indicating that there have been 

instances where engine ECM’s took 

control from the operator during water 

pumping operations. When an 

automatic active regeneration is 

initiated during a water pumping 

operation, for example, an ECM may be 

programmed to alter throttle position or 

engine speed to achieve the conditions 

needed to complete an automatic active 

regeneration. Depending on the design 

of the water pumping system’s pressure 

regulation, this may in turn affect the 

water pressure in the fire hoses. EPA 

has not heard of this occurring on a 

widespread basis, and has reason to 

believe that affected engine and truck 

manufacturers have identified and 

corrected this issue on some vehicles. 

EPA’s current regulations already allow 

manufacturers to develop and request 

EPA approval for certification of engines 

with emission control strategies where 

the process of undergoing automatic 

active regeneration would not interfere 

with safely pumping fire suppressant. 

EPA requests comment on whether any 

EPA action should be taken to explicitly 

address this situation beyond what we 

are already proposing in this action. 

While not addressed directly in this 

proposed action, there are technologies 

that could be implemented to decrease 

the amount of time emergency vehicles 

spend with their main engines operating 

at light loads and at idle. These 

technologies include electronically 

programmed automatic engine start/stop 

systems and hybrids. Automatic start/ 

stop systems automatically stop and 

start an engine depending upon whether 

or not it is needed to supply power to 

the vehicle. This technology is already 

being implemented on other heavy-duty 

vehicles to decrease unnecessary engine 

idling. Hybrid drivetrains also decrease 

engine idling with an integrated 

alternate power source such as a battery. 

We are currently seeing an increase in 

the use of hybrid technologies in heavyduty diesel vocational vehicles. Garbage 

trucks, utility company trucks, and 

other work trucks are using hybrid 

technology to power on-board hydraulic 

systems and cab heating and cooling 

systems. In conventional vehicles these 

systems are powered by a main engine 

typically operating at light load or at 

idle. Because automatic start/stop and 

hybrid technologies improve fuel 

economy and decrease greenhouse gas 

emissions, we believe that they will be 

used in more and more vehicles in the 

future. We believe there is potential for 

these technologies to be integrated into 

future designs of emergency vehicles to 

decrease their operation at light loads 

and at idle. Such technologies would 

not only improve fuel economy and 

decrease greenhouse gas emissions from 

emergency vehicles, they would also 

help to prevent their diesel particulate 

filters from becoming plugged due to 

excessive operation at light loads and at 

idle. While we are not proposing any 

specific action at this time related to 

decreasing the amount of time 

emergency vehicles operate at light load 

or at idle, we request comment on the 

potential for application of alternate 

power sources and idle reduction 

technologies on emergency vehicles. 

(3) What are the concerns for emergency 

vehicles using SCR? 

Selective Catalytic Reduction (SCR) is 

an exhaust after-treatment system used 

to control NOX emissions from heavyduty engines by converting NOX into 

nitrogen (N2) and water (H2O). The 

technology depends on the use of a 

catalytic converter and a chemical 

reducing agent, which generally is in an 

aqueous urea solution, and is often 

referred to as diesel exhaust fluid (DEF). 

Some trade names for this chemical 

reductant include AdBlue, BlueDef, 

NOxBlue, and TerraCair. 

Most engine manufacturers chose to 

comply with the 2010 NOX emission 

standard by adding SCR to their engine 

models. In general, the approach with 

an SCR system has been a sound and 

cost effective pathway to comply with 

EPA’s 2010 emissions standards, and it 

is the primary path being used today. 

DEF is injected into the exhaust 

upstream of the SCR catalyst where it 

forms ammonia and carbon dioxide. The 

ammonia then reacts with NO and NO2, 

so that one molecule of urea can reduce 

two molecules of NO or one molecule of 

NO2. A robust SCR system can achieve 

about 90 percent reduction in cycleweighted NOX emissions. Improvements 

have been made over the last several 

years to improve the NOX conversion 

rate and reduce the impact of lower 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
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20FAMA 2010, Emergency Vehicle SCR and DEF 

Inducement Guidelines; 2010 Engine Emissions 

Control Requirements. 

21American Trucking Associations, Technology & 

Maintenance Council, S3 Engine Study Group. 

Survey conducted Fall 2011, public slides dated 

February 2012 available at http://

www.truckline.com/Federation/Councils/TMC/ 

Documents/2012%20Annual%20Meeting%20and

%20Exhibition%20Documents/TMC12A_

TECH2.pdf. 

22See ATA/TMC, Note 21. 

exhaust temperatures on the conversion 

efficiency. 

Because an SCR system is only 

effective when DEF is injected into the 

exhaust, we consider refilling a 

vehicle’s DEF tank to be a critical 

emission-related engine maintenance 

requirement. We are taking action 

elsewhere in this notice (See Section V) 

to establish this in our regulations. 

Therefore, manufacturers have 

implemented a number of strategies to 

induce a vehicle operator to refill a 

vehicle’s DEF tank when needed. These 

operator inducements generally include 

first illuminating one or more dashboard 

lights to warn the operator that the DEF 

tank needs to be refilled soon. However, 

if such initial inducements are 

persistently ignored by the vehicle 

operator, eventually additional 

inducements are typically activated that 

decrease the maximum speed or power 

of the vehicle. These additional 

inducements are intended to create 

conditions making operational 

conditions of the vehicle increasingly 

unacceptable if the initial dashboard 

lamp illumination inducements are 

persistently ignored. Similar 

inducements may occur in cases where 

DEF quality does not meet system 

specifications, or if the SCR system is 

not functioning correctly for another 

reason. 

While decreasing vehicle performance 

can be an effective inducement strategy, 

we believe it may not be appropriate in 

all situations for emergency vehicles 

because of their special need to be ready 

at any moment for the purpose of 

protecting public safety and welfare by 

saving human lives that may be in 

immediate danger. We recognized this 

during the initial implementation of our 

2010 NOX standards, and we worked 

with the Fire Apparatus Manufacturers’ 

Association (FAMA), the Ambulance 

Manufacturers Division of the National 

Truck Equipment Manufacturers 

Association, and the International 

Association of Fire Chiefs to support the 

publication of a May 18, 2010 memo 

that instructed emergency vehicle 

manufacturers and engine 

manufacturers to implement less severe 

inducement strategies for emergency 

vehicles.20 In this proposal we are 

taking additional steps so that 

emergency vehicle manufacturers and 

engine manufacturers have the option to 

further reduce the severity or eliminate 

altogether any performance related 

inducements that are or could be 

implemented on emergency vehicles 

and their engines during emergency 

situations. We believe that this 

additional flexibility will help to 

prevent any abnormal condition of a 

vehicle’s emission control system from 

adversely affecting the speed, torque, or 

power of an emergency vehicle during 

emergency situations. 

D. What would occur if EPA took no 

action? 

(1) The Industry Would Continue to Get 

Smarter 

Improving the components of diesel 

particulate filters is the current subject 

of research and development activities 

within the automotive and air pollution 

control industries. Aspects that are 

being improved include filter ash 

storage capacity, filter pressure drop, 

substrate durability, catalyst activity, as 

well as other physical and chemical 

properties that can optimize the device 

for heavy-duty vehicle applications. 

Engine manufacturers have taken a 

systems approach, optimizing the 

engine with its after-treatment system to 

realize the best overall performance 

possible. Manufacturers can manage the 

functioning of the emission control 

system by adjusting parameters such as 

the thermal profile of the after-treatment 

system, the exhaust gas chemical 

composition, the rate of consumption of 

DEF, the rate of particle deposition, and 

the conditions under which DPF 

regenerations (soot cleaning) may occur. 

In a broad and general sense, the 

trend is that DPF’s are slowly becoming 

even more robust without EPA 

intervention. Future DPF’s will need 

fewer total regenerations during the 

useful life of the engine and control 

system, more passive and fewer active 

regenerations will occur, and manual 

regenerations will become rarer. 

In addition, vehicle operators and 

fleet managers will continue to become 

more experienced with this new 

generation of sophisticated 

electronically-controlled vehicles. 

Manufacturers across the country are 

providing training on actions fleet 

managers can take to decrease problems 

with DPF regenerations. These actions 

include: 

• Use low-ash engine oils. 

• Avoid extended idling. 

• Maintain insulation on the exhaust 

pipe. 

• Maintain the crankcase filter. 

• Periodically operate a vehicle at 

higher speeds and loads. 

The Technology & Maintenance 

Council (TMC) of the American 

Trucking Associations conducted a 

survey in late 2011 to compare user 

experiences between EPA 2010, EPA 

2007, and EPA 2004 vintage trucks.21

According to TMC, 72 percent of the 

survey respondents indicated that driver 

understanding of the 2007-vintage aftertreatment system was worse than driver 

understanding of the 2004-vintage aftertreatment system, and 33 percent of 

respondents indicated that driver 

understanding of the 2010-vintage aftertreatment system was worse than driver 

understanding of the 2007-vintage aftertreatment system. The responses 

regarding driver understanding of fault 

codes and dash lamps indicated that 

drivers have 69 percent poorer 

understanding of 2007 vs. 2004 fault 

codes and dash lamps, and 50 percent 

poorer understanding of 2010 vs. 2007 

fault codes and dash lamps. We expect 

that this education component will 

gradually improve over time without 

EPA intervention. 

(2) The Fleet Would Continue to Migrate 

to the 2010 Standards 

Vehicles with 2010-compliant heavyduty diesel engines tend to place 

different demands on their DPF systems 

than pre-2010 vehicles. With the 

addition of NOX after-treatment such as 

SCR, engines may be tuned to emit 

lower engine-out PM (recall the NOXPM trade-off described above). When an 

SCR system is integrated, it provides the 

opportunity to run an engine at lower 

soot levels and elevated levels of NO2, 

which is a chemical species that 

efficiently oxidizes the soot in the 

absence of elevated temperatures. It is 

EPA’s expectation that vehicles of MY 

2010 and beyond, particularly those 

using SCR, will generally experience 

fewer troubles with DPF’s than the 

earlier model year vehicles, due to the 

nature of the on-board technology as 

well as the many years of experience 

gained by manufacturers since 2007. 

The 2011 TMC survey included an 

assessment of relative satisfaction levels 

between EPA 2010, EPA 2007, and EPA 

2004 vintage trucks. The survey results 

indicate that after-treatment durability 

is better with EPA 2010 trucks 

compared to EPA 2007 trucks, with less 

time out of service.22 As an illustration, 

according to a Volvo product brochure, 

the company’s EPA 2010-compliant 

trucks eliminate the need for active DPF 

regeneration, reducing driver 

involvement with the emission control 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
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23See Volvo 2010 product brochure, ‘‘Volvo’s 

SCR No Regen Engine,’’ available at http://www.

volvotrucks.com/SiteCollectionDocuments/VTNA_

Tree/ILF/Products/2010/09-VTM075_NoRegen_SS_

041609.pdf. 24See 40 CFR 86.082–2. 

25See 40 CFR 86.094–21 and 094–22. 

26U.S. General Services Administration, Federal 

Specification for the Star-of-Life Ambulance, 

August 1, 2007, http://www.deltaveh.com/f.pdf. 

27See National Fire Protection Association web 

page. Accessed April 2012 at http://www.nfpa.org/ 

catalog/product.asp?title=Code-1901-2009-

Automotive-Fire-Apparatus&category%5

Fname=&pid=190109&target%5Fpid=190109&src%

5Fpid=&link%5Ftype=search&icid=. 

system, using a design that allows for 

the DPF system to reliably oxidize 

accumulated soot using continuous 

passive regeneration.23

(3) Some Trucks Would Continue to 

Experience Problems 

Even though such trends would 

indicate that instances of emergency 

vehicles experiencing difficulty 

managing regeneration of DPF’s would 

decrease, in the absence of this EPA 

action, some vehicles would be likely to 

continue to experience some problems. 

EPA has learned that some engine 

manufacturers have disabled these 

engine protection measures on some 

emergency vehicles. In these cases the 

manufacturer has reasoned that an 

operator should be allowed to remain in 

control of an emergency vehicle even 

facing risk of catastrophic failure, with 

the consequences of that failure being 

less severe than the consequences of the 

vehicle prematurely losing power, 

torque and/or speed while performing 

emergency services. 

Without a clear action from EPA to 

provide the regulatory flexibility needed 

for swift deployment of robust remedies 

throughout the emergency vehicle fleet, 

implementation of best practices could 

be inconsistent, insufficient, or even 

impossible due to regulatory 

constraints. Some vehicles would 

continue to experience frequent 

plugging of DPF’s, frequent forced filter 

regenerations, and reduced engine 

power, speed or torque that diminish 

the ability of first responders to save 

lives and property. There would also 

remain a heightened risk that an 

emergency vehicle could be taken out of 

service when it is most needed. 

E. Proposed Regulatory Action 

As described above in Section IV.C, 

many DPF-equipped vehicles include 

engine controls and driver alerts that 

lead to decreases in maximum speed, 

torque, or power when DPF 

backpressure exceeds normal levels, as 

protective measures for either the 

engine or the DPF, or as inducements 

for the operator to immediately conduct 

DPF regeneration. Similarly, vehicles 

equipped with selective catalytic 

reduction (SCR) systems for NOX

reduction currently have engine 

controls and driver alerts that lead to 

eventual loss of speed, torque, or power 

when the SCR controls detect abnormal 

conditions (such as a malfunction, low 

DEF levels, etc.), as inducements to take 

immediate corrective action to allow the 

SCR to function normally. In most 

vehicles, these alerts and inducements 

may be easily avoided with normal 

driving and routine maintenance, and if 

activated, these inducements would not 

have any significant effect on public 

safety and welfare. In emergency 

vehicles, however, should any of these 

limits on maximum speed, torque, or 

power occur while a vehicle is 

responding to an emergency, it could be 

a matter of life or death. To address 

these issues that could otherwise limit 

the maximum speed, torque or power of 

an emergency vehicle’s engine when it 

is needed most, EPA is proposing to 

amend 40 CFR part 86 to revise the 

definition of defeat device; add new 

definitions of emergency vehicle, 

ambulance and fire truck; and add new 

labeling requirements for new onhighway engines with approved 

Auxiliary Emission Control Devices for 

emergency vehicles. EPA is also 

amending its regulations at 40 CFR part 

1039 to revise the definition of defeat 

device, add a new definition of 

emergency equipment, and add a new 

labeling requirement for nonroad 

engines with approved Auxiliary 

Emission Control Devices for emergency 

equipment. 

In our current regulations, engine 

manufacturers may request as part of an 

application for new engine or vehicle 

certification, and EPA may approve, 

Auxiliary Emission Control Devices, if 

they are not determined to be ‘‘defeat 

devices.’’ Auxiliary Emission Control 

Devices, or AECD’s, are any design 

element of an engine’s emission control 

system that senses temperature, vehicle 

speed, engine RPM, transmission gear, 

manifold vacuum, or any other 

parameter for the purpose of activating, 

modulating, delaying, or deactivating 

the operation of any part of the emission 

control system.24 Some AECD’s can 

temporarily decrease the effectiveness of 

an emission control system. This type of 

AECD is only permitted in very limited 

situations, for example, when such 

excursions are deemed to be necessary 

in order to protect the vehicle, engine, 

and or emission control system during 

limited modes of operation. 

A defeat device is a type of AECD that 

reduces the effectiveness of vehicle 

emission controls in situations when 

such reduction in effectiveness is not 

approved or permitted by EPA. Defeat 

devices are not permitted by the Clean 

Air Act or EPA. 

Approvals of AECD’s are made by 

EPA on a case-by-case basis. In 

applications for engine certification, 

manufacturers must include a detailed 

description of each AECD to be installed 

in or on any vehicle (or engine) covered 

by the application, as well as a detailed 

justification of each AECD that results 

in a reduction in effectiveness of the 

emission control system. According to 

40 CFR 86.094–21(b)(1)(i)(B), EPA may 

disapprove a request for an AECD based 

on consideration of currently available 

technology. Use of an unauthorized or 

disapproved AECD can be considered a 

violation of section 203 of the Act.25

In this action, EPA is proposing to 

revise the definition of defeat device at 

40 CFR 86.004–2, 86.1803–01, and 40 

CFR 1039.115 to exclude AECD’s that 

apply only for engines on emergency 

vehicles, where the need for an AECD 

is justified in terms of preventing the 

vehicle or equipment from losing speed, 

torque, or power due to abnormal 

conditions of the emission control 

system, or in terms of preventing such 

abnormal conditions from occurring 

during operation related to emergency 

response. 

In this action, EPA is proposing to 

define an emergency vehicle as a vehicle 

that is an ambulance or a fire truck. EPA 

is proposing to adopt a definition of 

ambulance consistent with the current 

U.S. General Services Administration 

Star of Life specification.26 EPA is 

proposing to define fire truck as a 

vehicle designed to be used under 

emergency conditions to transport 

personnel and equipment and to 

support the suppression of fires and 

mitigation of other hazardous situations, 

consistent with the scope of standards 

for automotive fire apparatus issued by 

the National Fire Protection 

Association.27 We are defining 

emergency equipment as specialized 

vehicles to perform aircraft rescue and 

firefighting functions at airports, or 

wildland fire apparatus. With these 

definitions, it is EPA’s intent to include 

vehicles that are purpose-built and 

exclusively dedicated to firefighting, 

emergency/rescue medical transport, 

and/or performing other rescue or 

emergency personnel or equipment 

transport functions related to saving 

lives and reducing injuries coincident 

with fires and other hazardous 

situations. EPA requests comment on 

whether we should refine or expand our 


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28Frequency in percent refers to the fraction of 

engine test cycles during which an automatic active 

regeneration occurs. 

definition of emergency vehicle within 

the scope of this action to include those 

equipped with heavy-duty diesel 

engines that serve other civilian rescue, 

law enforcement or emergency response 

functions. We are especially interested 

in information regarding instances of 

such vehicles experiencing or risking 

loss of power, speed or torque due to 

abnormal conditions of the emission 

control system, and how that may 

inhibit mission-critical life- and 

property-saving work. 

EPA is also proposing an associated 

engine labeling requirement so that 

engines with approved emergency 

vehicle AECD’s would be clearly 

identified and distinguished from other 

similar engines. 

As mentioned above in Section IV.C, 

some engine manufacturers currently 

specify that when an engine is sold for 

installation in an emergency vehicle, 

some of the default power, torque or 

speed inducements be de-activated or 

set to alternate, less severe settings. In 

such applications, when the DPF system 

requests regeneration, the warning lights 

remain illuminated while the vehicle 

remains in complete control of the 

driver. In these cases the manufacturer 

has likely reasoned that the 

consequences of catastrophic failure 

would be less severe than the 

consequences of the vehicle 

prematurely losing power, torque and/or 

speed while performing emergency 

services. EPA has granted related 

AECD’s in the past. 

However, without the proposed 

optional flexibilities provided by EPA in 

this action, manufacturers could be 

prevented from implementing truly 

failsafe solutions for all affected 

vehicles. For example, while current 

custom solutions may allow an 

emergency vehicle to continue pumping 

water or transporting a person to safety, 

its DPF would continue to accumulate 

particles and the risk of catastrophic 

failure would increase. 

In this action, EPA is proposing 

amendments so that manufacturers 

could apply for (and EPA could 

approve) AECD’s that would be justified 

in terms of preventing the occurrence of 

abnormal conditions of the emission 

control systems for emergency vehicles 

or in terms of preventing the engines 

from losing speed, torque, or power due 

to such abnormal conditions. In this 

context, EPA would consider abnormal 

conditions to be parameters outside 

normal ranges for proper operation, 

such as excessive exhaust backpressure 

from high soot loading on a DPF or 

insufficient DEF for use with an SCR 

system. 

EPA is encouraging manufacturers to 

apply for AECD’s that are tailored for 

engines on emergency vehicles, 

considering the duty cycle information 

presented above in Section IV.C(2)(b) 

along with any other information 

needed to design failsafe emission 

control systems for new emergency 

vehicles. EPA is also encouraging 

manufacturers to design field 

modifications to address these issues on 

in-use emergency vehicles, including 

those whose engines are no longer in 

production. Further discussion of field 

modifications is provided below in 

Section IV.F(2). 

To achieve these goals, EPA 

understands that increased flexibility 

would be needed because EPA’s strict 

NOX and PM standards present many 

design constraints. Below we describe 

some solutions that EPA believes it 

could approve as part of an emergency 

vehicle AECD or field modification, as 

proposed. Upon adoption of these 

amendments, EPA would encourage 

requests by engine manufacturers for 

emergency vehicle AECD’s and/or field 

modifications for in-use emergency 

vehicles for which service disruptions 

related to abnormal conditions of 

emission control systems may occur or 

have occurred. EPA suggests that such 

AECD’s or field modifications could 

include, but are not limited to, one or 

more of the following strategies: 

(1) Liberalized Regeneration Requests 

It is current practice that most modern 

diesel engine ECM’s are set to initiate an 

automatic active regeneration only 

above a designated DPF soot load, and 

those vehicles equipped with manual 

regeneration switches are set to not 

allow the option of initiating manual 

active regeneration until an even greater 

soot load is detected. The reason why 

manufacturers do this is related to 

certification of engine families and 

vehicle test groups. If manufacturers can 

limit the frequency of regenerations by 

design, then they can be assured that 

average emissions will remain below the 

certified average emission level. Excess 

regenerations could lead to higher 

average emissions, since some exhaust 

emissions increase during regeneration. 

Particularly for engines not equipped 

with SCR systems, NOX emissions can 

increase by an order of magnitude 

during regeneration, and these 

temporary increases in emission are 

accounted for in EPA’s certification 

process. See Section VII, below, for 

more information about the emissions 

impacts of DPF regenerations. In 

addition, excess regenerations could 

shorten the useful life of the DPF system 

since high temperatures place stress on 

filter substrates. 

EPA believes that emergency vehicle 

AECD’s that enable more frequent 

automatic active and manual active DPF 

regenerations, associated with a wider 

range of soot loads could improve the 

reliability of DPF systems without 

significantly compromising emissions 

reductions or durability. As explained 

below Section IV.F(4), EPA does not 

expect this provision to affect other 

aspects of certification. For emergency 

vehicles with approved AECD’s that 

involve changes in the frequency of 

regeneration, EPA proposes that the 

resulting increase in NOX emissions not 

be counted against certification levels 

for applicable engine families or vehicle 

test groups. Furthermore, EPA proposes 

that emissions certification testing be 

conducted with any approved AECD’s 

for emergency vehicle or equipment 

deactivated. According to EPA’s current 

engine certification data, engines from 

MYs 2008 and 2011 have an average 

maximum automatic active regeneration 

frequency near 20 percent, with the 

typical frequency between three and 

seven percent. Those with frequencies 

near zero rely almost exclusively on 

passive regeneration.28 EPA requests 

comment on whether an option for more 

frequent automatic active and/or 

manual active DPF regenerations for 

emergency vehicles would be beneficial 

for reliability of those DPF systems, and 

whether EPA should apply any 

constraints on the frequency of manual 

active DPF regenerations when 

approving AECD’s for emergency 

vehicles. 

(2) Engine Recalibration 

As mentioned above, in-cylinder 

combustion chemistry dictates a NOXPM trade-off where engines calibrated to 

reduce in-cylinder NOX tend to have 

higher PM levels. These factors lead to 

higher rates of particle accumulation 

and lower rates of particle oxidation on 

filters. EPA believes that AECD’s that 

incorporate engine calibration 

modifications could enable operation in 

a ‘‘low soot mode’’ with a reduced rate 

of particle deposition that would lead to 

more frequent and effective passive 

regenerations. Such calibration 

modifications could also extend the 

operating time between all types of 

regenerations, improve active 

regeneration effectiveness, and boost 

reliability of the DPF systems. On 

engines with downstream (i.e., SCR) 

NOX controls, SCR control could be 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
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modulated such that engine 

recalibration would not significantly 

affect NOX emissions. On engines 

without downstream NOX controls, EPA 

believes that some degree of increased 

NOX emissions during the conditions 

justified by the AECD would be 

approvable for emergency vehicles. As 

explained below in Section IV.F(4), EPA 

does not expect this provision to affect 

other aspects of certification. When 

manufacturers calculate the average 

NOX emissions during a test cycle, they 

incorporate data regarding both the 

frequency of regeneration and the 

increase in NOX emissions during 

regeneration. For emergency vehicles 

with approved AECD’s that involve 

recalibration to alter regeneration 

frequency or average NOX emissions, 

EPA proposes that the resulting increase 

in NOX emissions not be counted 

against certification levels for applicable 

engine families or vehicle test groups. 

Furthermore, EPA proposes that 

emissions certification testing be 

conducted with any approved AECD’s 

for emergency vehicle or equipment 

deactivated. A discussion of the 

estimated emissions impacts of 

recalibration is found below in Section 

VII.B. EPA requests comments on 

whether an upper limit of average NOX

emissions—considering regeneration 

frequency and duration, peak NOX

emission rate, and operating conditions 

under which the AECD is triggered— 

should be established as part of the 

implementation of this AECD option, 

and what levels may be appropriate. 

(3) Backpressure Relief 

It is EPA’s objective that all of our 

clean diesel emissions standards be 

implemented with reliable technologies 

that require a minimum amount of 

driver intervention and do not 

compromise the utility of vehicles. EPA 

understands that manufacturers are 

motivated to seek design solutions that 

are cost effective and easily deployable. 

However, by focusing solely on 

preventive measures such as those 

described above, manufacturers may not 

achieve a completely failsafe DPF 

strategy on all emergency vehicles. EPA 

anticipates that some vehicles may 

benefit from an additional failsafe 

measure that relieves engine exhaust 

backpressure as a last resort to prevent 

loss of engine speed, torque or power. 

There are products on the market today 

that could be configured to temporarily 

relieve excessive engine exhaust 

backpressure when detected, then 

return the system to normal at the 

instant that backpressure returns to a 

safe level. Such a device may be 

justified as a failsafe measure, and may 

be included as part of an overall strategy 

that also includes preventive measures, 

if justified and properly limited, where 

excess PM emissions would be expected 

to be emitted only during a small 

fraction of vehicle operation. That is, 

the vast majority of DPF operating 

cycles would be expected to have 

continuous PM emission control, while 

any temporary backpressure relief that 

reduced PM control or allowed bypass 

of controls would be expected relatively 

infrequently. EPA requests comment on 

whether a failsafe measure to provide 

engine exhaust backpressure relief 

should be available as an approvable 

AECD option, and what constraints, if 

any, should be established for this 

option. 

F. What engines and vehicles would be 

affected? 

Today’s proposal would apply to new 

and in-use fire trucks and ambulances, 

new and in-use airport fire apparatus 

and wildland fire apparatus, and heavyduty diesel engines on these emergency 

vehicles and equipment. 

(1) Newly Certified Engines and 

Vehicles 

Of those new diesel engines covered 

by EPA’s current heavy-duty diesel 

standards, only those installed in 

vehicles or equipment meeting the 

definition of emergency vehicle or 

emergency equipment would be eligible 

to obtain an approved AECD of the type 

discussed above in Section IV.E. Where 

a vehicle is chassis-certified and either 

sold as an incomplete vehicle to a truck 

body manufacturer or built and sold as 

a complete vehicle, only those sold and 

built as emergency vehicles would be 

eligible to obtain an approved AECD of 

the type discussed above in Section 

IV.E. 

(2) Certified Engines and Vehicles InUse 

To address in-use engines and 

vehicles, EPA proposes to allow engine 

and vehicle manufacturers to submit 

requests for EPA approval of Emergency 

Vehicle Field Modifications (EVFMs) for 

on-highway emergency vehicles and 

Emergency Equipment Field 

Modifications (EEFMs) for nonroad 

emergency equipment. EVFMs and 

EEFMs would be modifications to 

existing hardware and software to be 

installed on in-use vehicles or 

equipment to prevent loss of speed, 

torque, or power due to abnormal 

conditions of emission control systems, 

or to prevent such abnormal conditions 

from occurring, during vehicle or 

equipment operation related to 

emergency response. EPA proposes to 

use an approval process similar to the 

process that is currently utilized to 

submit modifications to current 

applications for certification, also 

known as ‘‘running changes.’’ The 

information submitted by a 

manufacturer to EPA as part of this 

request and approval process would be 

similar to the information submitted for 

emergency vehicle or equipment 

AECD’s. 

It is important to emphasize that this 

proposal would allow only those 

approved modifications to be deployed 

by manufacturers and their authorized 

dealers. Modifications made by end 

users are not generally approvable; 

rather the tampering prohibitions would 

generally apply to such modifications. 

EPA has identified three types of field 

modifications that would be permitted 

for emergency vehicles and emergency 

equipment under the proposed 

regulations, based on the extent to 

which the modification is being 

incorporated into new production 

vehicles and equipment. The three types 

are: 

• Type A: Any field modification that 

is a change to a certified vehicle (i.e., a 

vehicle, engine or equipment covered by 

a certificate of conformity) that is 

identical in all respects to a running 

change that is approved for 

incorporation in new vehicles by the 

manufacturer. Where the running 

change was approved by EPA for 

implementation only in conjunction 

with certain other running changes, the 

field modification may be considered to 

be a Type A field modification only if 

implemented under the same 

constraints. 

• Type B: Any field modification that 

is not identical in all respects to, but 

provides for essentially the same 

purpose as, a running change that is 

being incorporated in new vehicles by 

the manufacturer or that would have 

been incorporated if the vehicle were 

still in production. A Type B field 

modification is used when it is not 

practical to incorporate the exact 

running change in vehicles that have 

left the assembly line, or when the 

vehicles are no longer in production. 

• Type C: Any field modification that 

is made selectively only to vehicles 

which have left the assembly line and 

which would not have been 

incorporated on the assembly line. For 

example, this would apply when 

making a field modification to a vehicle 

that is no longer in production where 

there are no similar vehicles in 

production. 

The amount of justification needed for 

the field modification differs depending 


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29Although this action would not affect 

certification of engine families or test groups, EPA’s 

regulations do offer options to manufacturers who 

wish to ensure that emission-related maintenance 

will occur in use, including visible signals that are 

not reset until maintenance occurs. 40 CFR 86.004– 

25(b)(6)(ii). 

on which type of modification is being 

requested. 

(3) Labeling Requirements 

Because the engines and vehicles 

eligible for the AECD’s described in this 

proposal belong to broadly certified 

engine families and test groups, when 

they are sold for installation in an 

emergency vehicle and equipped with 

one or more approved emergency 

vehicle AECD’s, they must be labeled as 

such, to distinguish them from other 

certified engines. EPA is proposing 

adding a labeling requirement to 40 CFR 

part 86 subpart A, such that engines 

with one or more approved AECD’s for 

emergency vehicle applications must be 

labeled with the statement: ‘‘THIS 

ENGINE IS FOR INSTALLATION IN 

EMERGENCY VEHICLES ONLY.’’ EPA 

is also proposing adding a labeling 

requirement to 40 CFR part 86 subpart 

S, such that vehicles with one or more 

approved AECD’s for emergency 

vehicles, include the following 

statement on the emission control 

information label: ‘‘THIS VEHICLE HAS 

A LIMITED EXEMPTION AS AN 

EMERGENCY VEHICLE.’’ EPA is also 

adding a labeling requirement to 40 CFR 

part 1039, such that nonroad engines 

with one or more approved AECD’s for 

emergency equipment include a label 

with the following statement: ‘‘THIS 

ENGINE IS FOR INSTALLATION IN 

EMERGENCY EQUIPMENT ONLY.’’ 

EPA requests comment on whether 

these labeling requirements are 

satisfactory to ensure that engines and 

vehicles operating with approved 

emergency AECD’s are permanently 

distinguished from similar certified 

engines. EPA also requests comment on 

whether a similar label should be 

required for an in-use emergency 

vehicle or equipment where a field 

modification is deployed that prevents 

the engine from losing speed, torque, or 

power due to any occurrences of 

abnormal conditions of the emission 

control system, or prevents such 

abnormal conditions from occurring. 

(4) Other Regulatory Provisions 

Today’s proposal would not alter the 

tampering prohibition in 40 CFR 

1068.101(b)(1). This provision describes 

a general prohibition against anyone 

from removing or rendering inoperative 

an engine’s emission controls before or 

after entering into service, where an 

exception is provided in 

1068.101(b)(1)(ii) for engine 

modifications needed to respond to a 

temporary emergency, provided that the 

engine is restored to proper functioning 

as soon as possible after the emergency 

has passed. EPA encourages 

manufacturers to design their 

emergency vehicle AECD’s to be 

engaged only to the extent necessary to 

prevent the engine from losing speed, 

torque, or power due to abnormal 

conditions of the emission control 

system, or to prevent such abnormal 

conditions from occurring during 

operation related to emergency 

response. EPA recognizes that there may 

be cases where an AECD may need to 

be engaged at times other than while 

actively responding to an emergency, in 

order to assure that loss of speed, torque 

or power does not occur during 

operation related to emergency 

response. EPA also recognizes that some 

AECD’s may involve electronic 

approaches where the engine’s 

functions would be modulated based on 

exhaust backpressure or other 

parameters that are not correlated with 

any emergency situation. EPA may 

even, in extreme cases, such as at high 

altitude or with certain older MY 

engines allow engagement of AECD’s at 

all times, if they are justified as 

necessary to prevent engine from losing 

speed, torque, or power during 

operation related to emergency 

response. 

We would also encourage 

manufacturers to design their emission 

control systems to discourage 

tampering. According to EPA’s 

tampering prohibition, a vehicle 

operator who abuses or alters an 

approved AECD may be guilty of 

tampering. For example, if an AECD 

includes enabling an operator to initiate 

more frequent manual active 

regenerations, engine manufacturers 

may choose to prevent the abuse of this 

function by means such as a daily or 

weekly cap on the number of manual 

active regenerations, or a minimum soot 

loading for the function to engage. As 

another example, if an emergency 

vehicle alerts a driver to an abnormal 

condition of its emission control system 

by illuminating dash lamps, alarms or 

other warnings that do not limit vehicle 

performance, it is the operator’s 

responsibility to take prompt action to 

remedy the problem.29 If an operator 

disregards such warnings beyond the 

time needed to respond to the 

emergency, this may be considered 

tampering. It is important to note that if 

an emergency vehicle is not equipped to 

ever allow an operator to initiate a 

manual active regeneration, this may in 

practice encourage tampering by the end 

user. 

Manufacturers of highway and 

nonroad engines would be required to 

describe any emergency vehicle AECD 

in an application for certification. In 

this action, we are not proposing any 

revisions to the information needed to 

review and approve AECD’s. It is 

common practice for manufacturers, in 

describing AECD’s, to identify engine 

parameters such as those that would 

operate differently to preserve adequate 

engine performance during an 

emergency, including information about 

how the engine would respond under 

different in-use operating conditions 

under the various sets of conditions that 

would otherwise cause the engine to 

operate at less than full performance 

levels. Other than the requirement for a 

manufacturer to describe the emergency 

vehicle AECD in its application for 

certification, we do not expect this 

provision to be relevant for other 

aspects of certification. For example, 

EPA proposes that emissions 

certification testing be conducted with 

any approved AECD’s for emergency 

vehicle or equipment deactivated. 

Additionally, manufacturers would not 

need to consider emergency vehicle 

AECD’s when developing infrequent 

regeneration adjustment factors (IRAFs) 

or when developing deterioration 

factors (DFs). Thus, EPA proposes that 

manufacturers could include emergency 

and non-emergency engines and 

vehicles in the same engine families and 

test groups. EPA also proposes that 

manufacturers may apply for emergency 

vehicle AECD’s for new, existing, and/ 

or formerly approved emissions 

certificates. EPA requests comments on 

this aspect of the proposal. 

V. Scheduled Maintenance and 

Maintenance Interval for Replacement 

of Diesel Exhaust Fluid 

EPA is proposing to include new 

provisions in its regulations that 

explicitly permit replacement of diesel 

exhaust fluid (DEF) as part of approved 

emission-related scheduled 

maintenance and set out the permitted 

maintenance intervals for replacement 

of DEF on diesel fueled new motor 

vehicles, new motor vehicle engines and 

new nonroad compression-ignition 

(NRCI) engines. 

A. Background 

EPA’s regulations define the 

emission-related scheduled 

maintenance that may be performed for 

purposes of durability testing and for 

inclusion in maintenance instructions 

provided to purchasers of new motor 

vehicles and new motor vehicle engines. 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
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30See letter dated March 31, 2009 from Giedrius 

Ambrozaitis, Alliance of Automobile 

Manufacturers, Director, Environmental Affairs to 

Karl Simon, EPA, Director, Compliance and 

Innovative Strategies Division; Letter dated May 8, 

2009 from Jed Mandel, Engine Manufacturers Ass’n 

to Karl Simon, EPA, Director, Compliance and 

Innovative Strategies Division; Letters dated June 

29, 2009 and October 8, 2009 from Steven C. Berry, 

Director Government Relations Volvo Powertrain. 

31See letter dated July 20, 2010 from Giedrius 

Ambrozaitis, Alliance of Automobile 

Manufacturers, Director, Environmental Affairs to 

Karl Simon, EPA, Director, Compliance and 

Innovative Strategies Division; Letter dated June 13, 

2011 from Timothy A. French, Engine 

Manufacturers Ass’n to Justin G. Greuel, EPA, 

Compliance and Innovative Strategies Division; 

Letter dated April 28, 2011 from Steve Berry, Volvo 

Powertrain; Letters dated August 18, 2011 and 

September 27, 2011 to Karl Simon, EPA, Director, 

Compliance and Innovative Strategies Division from 

R. Latane Montague, Hogan Lovells. 

See 40 CFR 86.094–25(b); 40 CFR 

86.004–25(b); 40 CFR 86.1834–01(b). 

The regulations include lists of 

emission-related maintenance and 

intervals for this maintenance. See 40 

CFR 86.004–25(b)(4); 40 CFR 86.1834– 

01(b)(4). For example, in general, the 

maintenance interval for the adjustment, 

cleaning, repair of the following items is 

100,000 miles of use, and then at 

100,000 mile intervals thereafter for 

diesel cycle light-duty vehicles, diesel 

cycle light-duty trucks, and light heavyduty diesel engines and at 150,000 mile 

intervals for medium and heavy heavyduty diesel engines: Fuel injectors, 

turbochargers, electronic engine control 

units, particulate trap or trap-oxidizers, 

exhaust gas recirculation systems, and 

catalytic converters. The regulations 

also include a procedure that allows 

manufacturers to request a different 

maintenance schedule or to request new 

scheduled maintenance, which includes 

maintenance that is a direct result of the 

implementation of new technology not 

found in production prior to the 1980 

model year. See 40 CFR 86.094–25(b)(7); 

40 CFR 86.1834–01(b)(7). 

Similarly, EPA’s regulations 

applicable to nonroad compressionignition (NRCI) engines define the 

emission-related maintenance that may 

be performed for purposes of providing 

ultimate purchasers written instructions 

for properly maintaining and using the 

engine. Such emission-related 

maintenance and associated intervals 

apply to service accumulation on 

emission-data engines. See 40 CFR 

1039.125. This regulation includes lists 

of emission-related maintenance and 

intervals for this maintenance. See 40 

CFR 1039.125(a)(2) and 1039.125(a)(3). 

For example, in general, the 

maintenance interval for adjustment, 

cleaning, repair or replacement for 

catalytic converters on engines below 

130 kilowatt (kW) may not occur more 

frequently than after 3,000 hours and 

4,500 hours for engines at or above 130 

kW. This regulation also includes a 

procedure that allows manufacturers to 

request a different maintenance 

schedule or to request new scheduled 

maintenance, which includes 

maintenance on emission-related 

components that were not in 

widespread use on NRCI engines prior 

to 2011. 

EPA adopted new emission standards 

applicable to emissions of NOX from 

light-duty vehicles and trucks on 

February 10, 2000 (65 FR 6698). 

Similarly EPA adopted new standards 

applicable to emissions of NOX from 

heavy-duty highway engines and 

vehicles on January 18, 2001 (66 FR 

5002). These standards have been 

phased in since model year 2004 and all 

were fully phased-in by 2010. Most 

manufacturers of affected diesel engines 

and vehicles have chosen to use a NOX

reduction technology known as 

selective catalytic reduction (SCR) in 

order to meet these requirements. SCR 

systems use a nitrogen-containing 

reducing agent that usually contains 

urea and is known as diesel exhaust 

fluid (DEF). The DEF is injected into the 

exhaust gas and requires periodic 

replenishment by refilling the DEF tank. 

In addition, EPA adopted new 

emission standards applicable to 

emissions of NOX from NRCI engines on 

June 29, 2004 (69 FR 38958). These 

standards have begun to be 

implemented pursuant to a phase-in 

that began in the 2011 model year. EPA 

conducted a webinar workshop on July 

26, 2011 with NRCI engine 

manufacturers to address the 

application of SCR emission technology. 

Some manufacturers are currently 

certifying their NRCI engines with the 

use of SCR systems and we expect that 

many manufacturers will use SCR 

systems to meet the final Tier IV NOX

reduction requirements for their diesel 

engines. 

In a Guidance Document signed on 

March 27, 2007 (CISD–07–07), EPA 

indicated its belief that the requirements 

for critical emission-related 

maintenance would apply to 

replenishment of the DEF tank and that 

manufacturers wanting to use SCR 

technology would likely have to request 

a change to scheduled maintenance per 

40 CFR 86.1834–01(b)(7) or 86.094– 

25(b)(7). 

Following the completion of the 

Guidance, EPA received several requests 

for new maintenance intervals for SCRequipped motor vehicles and motor 

vehicle engines.30 EPA granted these 

requests for model years 2009 through 

2010 for light-duty vehicles and 2009 

through 2011 for heavy-duty engines, in 

a notice that was published in the 

Federal Register (74 FR 57671, 

November 9, 2009). In granting the 

requests, EPA stated that it 

believes the maintenance of performing DEF 

refills on SCR systems should be considered 

as ‘critical emission-related scheduled 

maintenance.’ EPA believes the existing 

allowable schedule maintenance mileage 

intervals applicable to catalytic converters 

are generally applicable to SCR systems 

which contain a catalyst, but that the DEF 

refills are a new type of maintenance 

uniquely associated with SCR systems. 

Therefore, the 100,000-mile interval at 40 

CFR § 86.1834–01(b)(4)(ii) for catalytic 

converters on diesel-cycle light-duty vehicles 

and light-duty trucks (and any other chassiscertified vehicles) and the 100,000-mile 

interval (and 100,000 mile intervals 

thereafter) for light heavy-duty diesel engines 

and the 100,000-mile interval (and 150,000 

mile intervals thereafter) for medium and 

heavy heavy-duty diesel engines at 40 CFR 

§ 86.004–25(b)(4)(iii) are generally applicable 

to SCR systems. As noted, the SCR systems 

are a new type of technology designed to 

meet the newest emission standards and the 

DEF refill intervals represent a new type of 

scheduled maintenance; therefore, EPA 

believes that manufacturers may request from 

EPA the ability to perform the new scheduled 

maintenance of DEF refills. 

EPA approved a maintenance interval 

for refill of DEF tanks equal to the 

applicable vehicle’s scheduled oil 

change interval for light-duty vehicles 

and light-duty trucks. For heavy-duty 

engines, EPA approved a maintenance 

interval equal to the range (in miles or 

hours) of the vehicle operation that is no 

less than the vehicle’s fuel capacity (i.e., 

a 1:1 ratio), for vocational vehicles such 

as dump trucks, concrete mixers, refuse 

trucks and similar typically centrally 

fueled applications. For all other 

vehicles equipped with a constantly 

viewable DEF level indicator (e.g. a 

gauge or other mechanism on the 

dashboard that will notify the driver of 

the DEF fill level and the ability to warn 

the driver of the need to refill the DEF 

tank before other inducements occur), 

EPA approved a DEF tank refill interval 

equal to no less than twice the range of 

vehicle’s fuel capacity (i.e., a 2:1 ratio). 

For all other vehicles that do not have 

a constantly viewable DEF level 

indicator, EPA approved a DEF tank 

refill interval equal to no less than three 

times the range of the vehicle’s fuel 

capacity (i.e., a 3:1 ratio). 

Engine and vehicle manufacturers 

provided additional requests for new 

maintenance intervals for vehicles and 

engines in model years not covered by 

the November 9, 2009 Federal Register 

notice.31 On January 5, 2012 (77 FR 

488), EPA approved new maintenance 


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Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34165 

intervals for the refill of DEF tanks 

applicable to light-duty vehicles and 

light-duty trucks, as well as for heavyduty engines for 2011 and later model 

years. For light-duty vehicles and lightduty trucks the approved interval for 

DEF refill remains at the scheduled oil 

change interval. For heavy-duty engines 

the approved maintenance interval for 

vocational vehicles remains at 1:1 and 

for all other types of heavy-duty 

vehicles the approved maintenance 

interval is 2:1. 

On July 26, 2011, EPA conducted a 

webinar workshop for NRCI engine 

manufacturers in order to provide EPA’s 

thinking, at the time, about the 

certification of SCR-equipped NRCI 

engines. EPA discussed the issue of 

maintenance intervals for the refill of 

DEF and instructed manufacturers to 

follow the regulatory provisions in order 

to petition EPA for what it thought were 

appropriate intervals. Following the 

workshop, EPA received several 

requests for new maintenance intervals 

for SCR-equipped NRCI engines. EPA 

granted these requests for 2011 and later 

model years in a notice that was 

published in the Federal Register (77 

FR 497, January 5, 2012). In granting the 

requests, EPA stated that it 

believes that SCR systems are a new 

technology and are properly considered a 

critical emission-related component. EPA 

believes the existing allowable schedule 

maintenance mileage intervals applicable to 

catalytic converters are generally applicable 

to SCR systems which contain a catalyst, but 

that the SCR systems are a new type of 

technology and that DEF refills are a new 

type of maintenance uniquely associated 

with SCR systems. Therefore, the 3,000 hour 

(engines below 130 kW) and 4,500 hour 

(engines at or above 130kW) intervals are 

generally applicable to SCR systems. As 

noted, the SCR systems are a new type of 

technology designed to meet the newest 

emission standards and the DEF refill 

intervals represent a new type of scheduled 

maintenance; therefore, EPA believes that 

manufacturers may request from EPA the 

ability to perform the new scheduled 

maintenance of DEF refills. 

EPA approved a maintenance interval 

for refill of DEF tanks that shall be no 

less than the equipment’s fuel capacity 

(i.e., a 1:1 ratio of DEF refill to fuel 

refill). 

B. Proposed Regulatory Action 

EPA is today proposing to add DEF 

replenishment to the list of scheduled 

emission-related maintenance for dieselfueled motor vehicles and motor vehicle 

engines, as well as for NRCI engines that 

use SCR. EPA is also proposing to 

incorporate appropriate maintenance 

intervals for this scheduled 

maintenance. 

(1) Scheduled Emission-Related 

Maintenance 

EPA is proposing to list DEF 

replenishment as scheduled emissionrelated maintenance in 40 CFR 86.004– 

25(b)(4) and 40 CFR 86.1834–01(b)(4) 

for diesel-fueled motor vehicles and 

motor vehicle engines, as well as 40 

CFR 1039.125(a)(2) and 40 CFR 

1039.125(a)(3) for NRCI engines that use 

SCR. 

Over the past several model years, 

since the implementation of the most 

recent standards for NOX, many 

manufacturers have chosen SCR as the 

technology used to meet these stringent 

NOX standards. Typically, should a 

manufacturer desire new maintenance 

(that it wishes to recommend to 

purchasers and perform during service 

accumulation on emission-data engines) 

not found in 40 CFR 86.004–25(b)(4) 

and 86.1834–01(b)(4) or at 40 CFR 

1039.125(a)(2) and 40 CFR 

1039.125(a)(3), then it utilizes the 

provisions allowing manufacturers to 

request such maintenance. Given that 

SCR use is now common in the industry 

and replenishment of DEF is necessary 

for SCR to be effective, it is appropriate 

to add DEF replenishment to the list of 

scheduled emission-related 

maintenance published in the Code of 

Federal Regulations (CFR), rather than 

rely on the provisions of paragraph 

(b)(7) for motor vehicles and paragraph 

1039.125(a)(5) for NRCI engines. 

(2) Maintenance Intervals for OnHighway Diesel Engines 

EPA is also proposing to incorporate 

appropriate maintenance intervals for 

this scheduled maintenance. In general, 

they are the same as were approved 

under the (b)(7) process. For light-duty 

vehicles and light-duty trucks, we are 

proposing an interval equal to the 

scheduled oil change interval for the 

vehicle. Light-duty vehicles and trucks 

do not have the carrying and storage 

capacity required for the quantity of 

DEF needed to satisfy longer 

maintenance intervals such as the 

100,000 mile scheduled maintenance 

interval generally applicable to catalytic 

converters. As EPA explained in its 

previous notices regarding this issue, 

automobile manufacturers have stated 

that it takes approximately an 8 gallon 

DEF tank to assure the DEF will last for 

the length of a typical scheduled oil 

change interval. Assuming an oil change 

interval of 10,000 miles, a DEF tank size 

of approximately 80 gallons would be 

required to meet a 100,000 mile DEF 

refill maintenance interval. Even a 16– 

20 gallon DEF tank (to meet a 2 oil 

change interval) would interfere with 

the space that is necessary for typical 

light-duty vehicle design and 

transportation needs of the consumer. 

Interior cabin volume and cargo space 

are highly valued attributes in light-duty 

vehicles and trucks. Manufacturers have 

historically strived to optimize these 

attributes, even to the point of switching 

a vehicle from rear-wheel drive to frontwheel drive to gain the extra interior 

cabin space taken up by where the drive 

shaft tunnel existed, or switching the 

size of the spare tire from a 

conventional sized tire to a small 

temporary tire to gain additional trunk 

space. Thus any significant interior, 

cargo or trunk space used to store a DEF 

tank would be unacceptable to 

customers. There are also packaging 

concerns with placing a large DEF tank 

in the engine compartment or in the 

vehicle’s undercarriage. Most vehicle 

undercarriages are already crowded 

with the engine, exhaust system, 

including catalytic converters and 

mufflers, fuel tank, etc. limiting any 

available space for a DEF tank. 

In addition to the inherently space 

constrained areas on the vehicle to place 

both fuel tanks and DEF tanks (an 

additional 8 gallon tank represents a 

very significant demand for space) the 

addition of the weight associated with 

the DEF represents significant concerns 

(e.g. performance and efficiency) on the 

operation of the vehicle. For example, 

assuming a density of 9 lb/gallon, an 8 

gallon DEF tank represents an 

additional 72 lbs on a vehicle already 

looking to optimize performance. 

Adding additional DEF tank size to even 

accommodate a two-oil change interval 

is not feasible or practical given these 

weight constraints. A requirement for a 

larger DEF tank may also have an 

adverse effect on the ability of a 

manufacturer to meet greenhouse gas 

emission standards and fuel economy 

standards. 

EPA notes that a DEF refill 

maintenance interval that is equivalent 

and occurring with the oil change 

interval is a fairly long interval (e.g. 

7,500 to 12,500 miles) for light-duty 

vehicles and trucks and is not likely to 

result in overly frequent maintenance 

under typical vehicle driving. EPA also 

believes that an adequate DEF supply 

will be available to perform the DEF 

refills at the stated intervals. EPA 

believes it important to also consider 

when, where and how often vehicle 

owners or operators are most likely to 

perform the DEF refill maintenance. For 

light-duty vehicles and light-duty 

trucks, EPA believes the requested DEF 

refill interval’s association with the oil 

change interval is appropriate given the 

likelihood of DEF availability at service 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
34166 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

32As discussed in Section IV above, we are 

proposing options for manufacturers of emergency 

vehicles and engines to avoid the harsh 

consequences of certain performance inducements. 

Since 2010, some manufacturers have been 

implementing guidance on alternative inducement 

criteria for emergency vehicles. 

33See 76 FR 32886 (June 7, 2011) and the studies 

cited at 32889–32891. 

stations and the likelihood that DEF 

refill would occur during such service. 

EPA also notes that heavy-duty 

engines that are certified as part of 

complete trucks have been treated in the 

same manner as light-duty trucks and 

thus have been subject to the DEF refill 

interval associated with the oil change. 

We are proposing to continue this 

treatment in the regulations. In addition, 

EPA is aware that several manufacturers 

are exploring whether the DEF refill 

interval should not be linked to the oil 

change interval since the historical oil 

change interval (e.g., 7,000–8,500 miles) 

is potentially increasing to higher mile 

intervals (e.g., 15,000 to 30,000 miles, 

even higher for synthetic oil). We invite 

comment on the necessity and 

appropriateness of ‘‘de-linking’’ the DEF 

refill interval from the oil change 

interval, as well as comments on proper 

methods to increase the likelihood that 

DEF refill maintenance would occur in 

the appropriate interval (e.g., linking to 

vehicle fuel capacity, inducement 

criteria, etc.), should it not be linked to 

the oil change interval. 

For heavy-duty engines, we are 

proposing that for vocational vehicles 

such as dump trucks, concrete mixers, 

refuse trucks and similar typically 

centrally fueled applications, the DEF 

tank refill interval should equal the 

range (in miles or hours) of the vehicle 

operation that is no less than the 

vehicle’s fuel capacity (i.e., a 1:1 ratio). 

For all other vehicles, the DEF tank 

refill interval must provide a range of 

vehicle operation that is no less than 

twice the range of vehicle’s fuel capacity 

(i.e., a 2:1 ratio). EPA believes it is 

reasonable to base the DEF refilling 

event on diesel refueling intervals given 

that it is likely that the DEF refill 

maintenance would be undertaken at 

the time of fuel refill due to DEF 

infrastructure developed at diesel 

refueling stations. EPA believes that 

these DEF refilling intervals are 

technologically necessary. EPA knows 

of no SCR technology for any heavyduty engine application that is capable 

of operating without a DEF refill for the 

high mileage levels associated with 

other maintenance intervals. As an 

example, assuming that 25,000 gallons 

of diesel fuel were consumed to reach 

a 150,000-mile interval, the amount of 

DEF required (assuming a 3% DEF 

consumption rate) would require 750 

gallons of DEF weighing approximately 

6,750 lbs. A line-haul truck is allowed 

a maximum gross vehicle weight of 

85,000 lbs. of which approximately 

45,000 pounds is for cargo carrying. A 

DEF tank of 750 gallons would reduce 

the cargo-carrying capacity by 15%. 

Another example from the line haul 

industry suggests that a DEF tank size of 

over 900 gallons would be needed to 

reach the 150,000-mile interval for a 

common highway vehicle with a diesel 

fuel capacity of 200 gallons and 

achieving 6.5 miles per gallon fuel 

economy. Similarly, a medium heavyduty engine (‘‘chassis cabs’’) example 

would require 375 gallons of DEF 

weighing 3,275 lbs to meet a 150,000- 

mile interval. EPA believes that such 

tank sizes are clearly not technologically 

feasible in light of the weight and space 

demands and constraints on heavy-duty 

trucks and the consumer demand to 

maximize cargo carrying capacity. 

The Agency also believes that 

intervals shorter than 150,000 miles but 

longer than those we are proposing 

would require DEF tanks that are too 

large or too heavy to be feasibly 

incorporated into vehicles. Available 

data show that heavy-duty engines 

equipped with SCR-based systems will 

consume DEF at a rate that is 

approximately 2%-4% of the rate of 

diesel fuel consumption. Because of 

inherent space and weight constraints in 

the configuration and efficient operation 

of heavy-duty vehicles, there are size 

limits on the DEF tanks. Currently, there 

are truck weight limits that 

manufacturers must address when 

making or modifying truck designs. EPA 

expects and believes that manufacturers 

are taking significant and appropriate 

steps in order to install reasonably sized 

DEF tanks to achieve the DEF refills 

intervals noted. For example, 

manufacturers are taking such steps as 

reducing the number of battery packs on 

vehicles despite customer demands or 

designing space saving configurations, 

in some instances extending an already 

very limited frame rail distance to 

incorporate the DEF tanks and SCR 

systems, moving compressed air tanks 

inside the frame rails, redesigning fuel 

tank configurations at significant costs, 

and otherwise working with significant 

size and weight constraints to 

incorporate DEF tanks. There are several 

factors that support the good 

engineering judgment that underlies the 

recommended DEF refill intervals. The 

great majority of heavy-duty engines 

produced with SCR DEF tanks will 

provide a range of vehicle operation that 

is no less than twice the range of the 

vehicle’s fuel capacity; thus, the DEF 

tank size will provide at least double the 

vehicle’s operating range as provided by 

the fuel tank. Vehicle operators will 

generally refill DEF at the same time 

and location that they refill the tanks 

thus these vehicles will already be 

carrying twice as much DEF as the SCR 

system could ever consume between 

refills. Also, manufacturers have been 

incorporating warning signals and 

performance-related inducements on 

their SCR-equipped vehicles to ensure 

the substantial likelihood that DEF 

refilling will occur,32 and there is 

considerable evidence that heavy-duty 

vehicle operators in the United States 

have in practice been refilling their DEF 

tanks prior to the tanks becoming empty 

in virtually all situations.33

EPA was provided with examples of 

the consequences of requiring heavyduty vehicles to accommodate a DEF 

refill interval of 5:1, and the information 

provided to the Agency strongly 

suggested that great compromises would 

be required in cost, weight and utility. 

Increased tank sizes and weights on the 

magnitude of 150 to 325 lbs. would be 

required and in some cases diesel fuel 

volumes would need to be reduced. The 

extra weight associated with the DEF 

required to meet the 2:1 refill intervals 

represents a significant challenge to 

manufacturers seeking to meet both 

weight and size requirements for their 

vehicle designs. In addition, requiring a 

longer DEF refill interval may result in 

increased greenhouse gases and 

decreased fuel economy. EPA believes 

that in light of the existing tight space 

constraints and the overall desire to 

maximize cargo-carrying capacity to 

minimize emissions and meet consumer 

operational demands, and the built-in 

DEF tank size buffer to insure DEF 

refills, that the proposed tank DEF tank 

sizes are technologically necessary and 

are also reasonable and appropriate. 

EPA believes that requiring tank sizes 

above these ratios will cause increases 

in space constraints and weight that 

would not be appropriate for these 

vehicles. Similarly, manufacturers note 

that only a small number of applications 

will employ the 1:1 refilling ratio and 

that such vehicle applications have very 

limited vehicle space available to house 

surplus DEF. Such applications (e.g., a 

garbage truck, concrete mixer, beverage 

truck, or airport refueler) will also be 

refueled daily at central locations. At 

approximately 0.134 ft3 per gallon, any 

extra DEF would displace significant 

space available to vehicle components 

and subsystems on both the vocational 

trucks at the 1:1 refill interval as well as 

the 2:1 vehicles. 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34167 

34See 77 FR 488, at 495–96 (January 5, 2012). 

35See letters dated August 18, 2011 and 

September 27, 2011 to Karl Simon, EPA, Director, 

Compliance and Innovative Strategies Division from 

R. Latane Montague and Hogan Lovells. 

During the previous administrative 

process leading to the January 5, 2012 

Federal Register notice approving new 

maintenance intervals, EPA received a 

comment from one manufacturer 

(Navistar) suggesting that a longer DEF 

refill interval in the range of 35,000 to 

45,000 miles was appropriate. EPA 

responded to these comments in detail 

in that notice.34 As discussed in that 

notice, Navistar claimed that other 

technology is available that would need 

a maintenance interval no shorter than 

this. However, EPA found no evidence 

that such technology is actually 

available at this time. More importantly, 

the fact that other technology may be 

able to have a longer maintenance 

interval does not mean that a longer 

maintenance interval is appropriate for 

DEF-based SCR. Navistar suggested that 

maintenance intervals can be increased 

by doubling DEF tank size. EPA does 

not believe that requiring such an 

increase is appropriate given the 

numerous negative consequences 

discussed above. EPA also explained 

that Navistar’s suggestion of reducing 

engine-out emissions of NOX would 

likely lead to an increase in fuel 

consumption, and possible increases in 

GHG emissions, and could either 

require increases in the size of the fuel 

tank or more reductions in the operating 

range of a vehicle before needing to 

refill, which would compromise a 

critical design parameter of heavy-duty 

vehicles. EPA does not believe the 

desire to increase DEF maintenance 

intervals justifies such consequences. 

After reviewing these data, EPA believes 

that longer refill intervals than those 

proposed above would require larger 

and heavier DEF tanks. The design and 

engineering work performed by 

manufacturers thus far indicates that the 

recommended DEF refill intervals noted 

above approximate the maximum 

feasible maintenance intervals 

associated with reasonable DEF tank 

sizes. In any case these refill intervals 

are appropriate and reasonable given the 

substantial negative consequences of 

longer DEF refill interval requirements. 

The recommended maintenance 

intervals ensure that the function and 

operational efficiency of such vehicles 

are not overly compromised. Based on 

this information we believe the 

proposed intervals are warranted. 

EPA has received comments from 

certain manufacturers indicating that 

EPA should set the minimum required 

DEF refill interval at an interval equal 

to the vehicle’s fuel capacity (i.e., a 1:1 

ratio) for all heavy-duty engines.35 The 

commenters claim that this shorter 

maintenance interval is ‘‘necessary and 

appropriate to reflect current and 

anticipated changes in vehicle designs, 

significant changes in inducement 

strategies, and the increased availability 

of DEF.’’ The commenters note that 

certification practices of the EPA 

regarding inducement practices for SCRequipped engines make it ‘‘essentially 

impossible for an SCR vehicle to operate 

without regular DEF replenishment.’’ 

They state that the severity of 

inducements related to DEF levels (e.g. 

severe reduction in engine power and/ 

or vehicle speed) is ‘‘extraordinary and 

must be taken into account’’ when EPA 

is determining appropriate maintenance 

intervals. They state that ‘‘in light of 

these severe inducements, it is 

reasonable to expect that a driver with 

a 1:1 tank ratio will operate under a firm 

discipline that the DEF tank must be 

refilled every time the fuel tanks are 

filled, as opposed to a driver with a 2:1 

or greater tank ratio who may become 

accustomed to filling the DEF tank only 

when necessary, and is therefore more 

likely to rely on gauge levels, warnings, 

and inducements to trigger refills.’’ 

The commenters also state that EPA’s 

promulgation of new standards 

regulating greenhouse gases increase the 

size and weight restraints associated 

with DEF tank size. 

EPA has adopted new greenhouse gas 

standards for heavy-duty on-highway 

trucks, and manufacturers have moved 

to voluntarily increase the fuel 

efficiency of their vehicles in advance of 

the effective dates of those regulations. 

Within these regulations, EPA 

recognizes the impact of weight savings 

on fuel efficiency and GHG emissions. 

In addition, manufacturers have 

developed innovative new DEF dosing 

strategies to reduce CO2 emissions. 

These new strategies may involve 

increasing the DEF dosing rate. 

Increasing the DEF dosing rate also 

makes it more difficult to satisfy a 2:1 

tank size ratio without increasing the 

size of the DEF tank above the size EPA 

previously considered the maximum 

reasonable size. For this reason, if the 

application of the 1:1 tank ratio is not 

expanded, EPA will effectively be 

mandating larger DEF tanks, with their 

accompanying weight increase, in order 

to accommodate technology 

advancements developed to reduce CO2

emissions—tanks that are larger than the 

tanks EPA determined to be the 

maximum reasonably required in 2009. 

In addition, this could inadvertently 

cause manufacturers to restrict 

application of the most fuel efficient 

engines to vehicles that have reduced 

range between fuel and DEF refills, such 

that they will be unattractive to the linehaul fleets that consume the most fuel. 

The commenters elaborated that: 

To meet the next round of GHG reduction 

requirements, some manufacturers expect to 

increase DEF dosing by as much as 100% 

over current levels. These increased levels of 

dosing will require a corresponding increase 

in DEF tank capacity and size to meet the 

existing 2:1 tank ratio requirements. For 

example, increasing DEF dosing by 40% on 

average would require an increase in DEF 

tank size of approximately 40% (depending 

on how much extra capacity was included in 

the tanks used in previous model years). The 

shape, size and location of DEF tanks on a 

truck frame are constrained by a number of 

factors including: the need to place the tank 

below the filler-neck; the need for clearance 

from other components such as fuel tanks, 

battery boxes, air tanks, diesel particulate 

filters, and the drive axle and wheels; the 

need for gravity feed; body installation 

requirements; clear-back-of-cab requirements; 

weight distribution requirements; bridge 

formula and related axle placement issues; 

and fuel capacity/driving range demands. 

The commenters state that another 

consequence of the greenhouse gas 

regulations is more attention to 

improved aerodynamics and weight 

reduction, which are harmed by the 

need for a 2:1 DEF tank size 

requirement. They claim that EPA 

should allow manufacturers to use all 

available options to increase fuel 

efficiency and meet greenhouse gas 

standards. They claim that the possible 

harm of allowing shorter maintenance 

intervals are minimal, given the severe 

negative inducements associated with 

failure to replenish the DEF tank. 

EPA is not proposing to allow a 1:1 

DEF maintenance interval across the 

heavy-duty engine class at this time. 

EPA notes that manufacturers have been 

meeting a 2:1 ratio for DEF tank size for 

the past two years and the commenters 

have not provided sufficient evidence 

that this ratio will be infeasible in the 

future. Moreover, the commenters have 

not shown that any change in the 

maintenance interval is necessary or 

appropriate throughout the heavy-duty 

engine category, rather than for 

particular applications, or that a refill 

interval as low as 1:1, rather than 1.8:1 

or 1.5:1, is necessary or appropriate. The 

feasibility of the greenhouse gas 

standards was not predicated on 

substantial increases in DEF dosing rate, 

although that was a possible method of 

compliance, and the commenters have 

not shown that the increase in tank size 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
34168 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

36See 40 CFR 1039.125(a)(5). 

37See 76 FR 32886 (June 7, 2011) and related 

inducement criteria, see also Note 32 above 

regarding inducements for emergency vehicles and 

engines. 

that would be associated with increased 

dosing, which need not be large, would 

be inconsistent with space constraints. 

While EPA agrees that the warnings and 

inducements in place for failure to 

replenish DEF will restrict the ability of 

operators to run without DEF, and have 

made operation without DEF virtually 

unheard of, a DEF tank ratio of 1:1 

greatly increases the likelihood that 

operators will need to make more 

frequent stops to replenish DEF, and 

possibly may need to stop solely to 

replenish DEF, which may place a 

greater burden on the operator in terms 

of the frequency of DEF refills. 

However, we request comment on this 

proposal and we do not rule out the 

possibility we may in the final rule 

allow a shorter maintenance interval at 

least in some situations beyond what we 

have proposed. In particular, we request 

comment on whether such an interval 

may be appropriate in the future or 

whether an approach that is limited to 

a portion of the heavy-duty engine 

category or that uses an interval 

between 2:1 and 1:1 may be appropriate. 

EPA also notes that the regulations 

allow any manufacturer to petition EPA 

under the ‘‘paragraph (b)(7) process’’ for 

a shorter maintenance interval than that 

promulgated for DEF refills if the 

manufacturer can show that a shorter 

interval is technologically necessary for 

the particular engine or vehicle 

configuration being certified. 

(3) Maintenance Intervals for Nonroad 

Compression-Ignition Engines 

EPA is also proposing to incorporate 

appropriate maintenance intervals for 

the scheduled maintenance of DEF 

refills on SCR-equipped NRCI engines. 

We are proposing the same interval (i.e., 

1:1 ratio) as was approved under the 

§ 1039.125(a)(5) process. 

EPA believes it appropriate to 

evaluate the DEF refill rates by taking 

into consideration the space and weight 

constraints typically involved with the 

range of nonroad compression-ignition 

engines using SCR systems, including 

safety and impacts of weight and dosing 

rates on greenhouse gas emissions and 

fuel economy. EPA also believes it 

appropriate to take into consideration 

the likelihood that the maintenance of 

DEF refills will be performed by the 

owner or operator.36

EPA knows of no SCR technology for 

NRCI engines that is yet capable of 

attaining longer operation (generally 

beyond one tank full of diesel) without 

a DEF refill. As noted by the requests 

received for a shorter interval, there are 

significant space and weight constraints 

associated with increasing the DEF tank 

size in order to accommodate a 2:1 refill 

ratio. EPA believes it appropriate to take 

into consideration the need for locating 

the DEF tank in close proximity to the 

fuel tank and the remainder of the SCR 

system, as well as the increased 

likelihood that the DEF tank will be 

refilled if it becomes standard operating 

practice to refill it at the same time as 

the fuel tank. EPA believes that such 

nonroad equipment is similar to 

centrally-fueled heavy-duty on-highway 

vehicles and that there is a sufficient 

basis and a reasonable expectation that 

DEF tank refills will occur on a timely 

basis. In addition, because this 

maintenance is considered critical 

emission-related maintenance, 

§ 1039.125 requires that manufacturers 

ensure that it have a reasonable 

likelihood of being done at the 

recommended intervals on in-use 

engines. Paragraph 1039.125(a)(1) sets 

forth several methods by which such 

demonstration can be made, including 

data showing that if a lack of 

maintenance increases emissions, it also 

unacceptably degrades the engine’s 

performance. Thus, manufacturers will 

need to show compliance with this 

requirement to be certified. In the 

context of SCR systems and the 

potential of an empty DEF tank and an 

inoperable SCR system, EPA notes that 

equipment under such operating 

conditions are expected to shut down or 

idle only.37

VI. Nonroad Engines in Temporary 

Emergency Service 

As noted previously, EPA is 

proposing to adopt special provisions 

for engines used in dedicated 

emergency vehicles to ensure that 

manufacturers are able to design and 

implement reliable, robust emission 

control systems with regeneration 

strategies that do not interfere with the 

mission of emergency vehicles. 

However, we are not proposing to 

extend this option for other engines that 

are not intended for emergency vehicles. 

Nevertheless, based on information 

provided to us from engine 

manufacturers, we have some concern 

that nonroad engines not normally used 

for emergencies may be needed in 

unusual emergency situations that may 

require very limited and temporary 

relief so that emission controls do not 

hinder the engine’s performance in such 

emergency conditions. This section 

describes a flexibility that we are 

proposing to address this. 

Our existing nonroad engine 

compliance regulations in 40 CFR 

1068.101(b)(1)(ii) allow operators to 

temporarily disable or remove emission 

controls to address emergency 

situations. However, they do not 

necessarily allow manufacturers to 

design the emission controls to be 

disabled or removed. This has become 

a potential problem for modern 

electronically controlled engines, where 

many emission controls are integrated 

into the engine’s control software. There 

is currently no way for an operator to 

selectively disable emission control 

software, while maintaining engine 

function. The proposed regulatory text 

would effectively extend the policy 

expressed in 40 CFR 1068.101(b)(1)(ii) 

to emission control software. 

A. Use of Nonroad Engines in 

Emergency Situations 

The provisions we are proposing are 

intended primarily to address engines 

used for power generation or in 

construction equipment. However, it is 

important to note that we are not 

proposing to limit this flexibility to such 

engines. For example, portable dieselpowered generators are often used to 

provide electrical power after natural 

disasters. If the generator is providing 

power to a medical facility, then any 

interruption in service could risk the 

lives of the patients. This is just one 

example of how an ordinary piece of 

nonroad equipment could be used in an 

emergency situation. Others would 

include bulldozers repairing a levee or 

a crane removing debris. 

The Tier 4 standards have resulted in 

much of this equipment being equipped 

with SCR catalysts that require a 

reductant. The reductant is typically 

supplied as a urea water solution known 

as diesel exhaust fluid (DEF). The 

engines in this equipment generally 

include controls that limit the function 

of the engines if they are operated 

without urea. Such controls are 

generally call ‘‘inducements’’, because 

they induce the operator to supply urea 

to the equipment. While we are 

confident that DEF is now widely and 

easily available in the United States, we 

are concerned that in emergency 

circumstances there may be a possibility 

of a temporary supply shortage. We 

believe that in such situations, 

temporary flexibilities may be 

appropriate because the possibility of 

risk to human life sufficiently outweighs 

the temporary emissions increases that 

may occur if SCR-equipped engines are 

used without DEF. As indicated below, 

this flexibility is very narrow and 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34169 

contains several provisions to ensure 

the need for the relief. We do not 

believe it can or will be used in 

situations where there is no critical 

need for such relief. 

B. Proposed Regulatory Action 

(1) General Requirements 

We are proposing a new section 

1039.665 that would specify provisions 

that allow for AECDs that are necessary 

to ensure proper function of engines and 

equipment in emergency situations. 

AECDs approved under this section 

would not be defeat devices. The 

section would include the following 

provisions: 

• Manufacturers would be allowed to 

ask for approval at any time. Still, we 

would encourage manufacturers to 

obtain preliminary approval before 

submitting an application for 

certification. And in unusual 

circumstances, we could allow 

manufacturers to apply an approved 

emergency AECD to engines and 

equipment that have already been 

placed into service as a ‘‘field fix’’. 

• The manufacturer would be 

required to keep records to document 

requests for and use of emergency 

AECDs under this section and submit a 

report to EPA within 60 days of the end 

of each calendar year in which it 

authorizes use of the AECD 

• We would approve an AECD only 

where we determine certain criteria are 

met, as described below. 

We are proposing to address such 

AECDs as part of certification and 

would only authorize the certifying 

manufacturer to activate them. 

(2) Approval Criteria 

Approval of AECDs under the 

proposed regulations would be based on 

certain general and specific criteria. A 

general criterion is that the AECD would 

need to be consistent with good 

engineering judgment. When used in 

our regulations, the phrase ‘‘good 

engineering judgment’’ has a specific 

meaning as described in 40 CFR 1068.5. 

By specifying that the AECD be 

consistent with good engineering 

judgment, we address unforeseen 

technical details that may arise. 

We are also proposing three specific 

criteria that must be met. Each of these 

criteria is intended to ensure that any 

adverse environmental impacts are 

minimized. These criteria are: 

• The AECD must be designed so that 

it cannot be activated without the 

specific permission of the certificate 

holder. We would specify that the AECD 

must require the input of a temporary 

code or equivalent security feature. 

• The AECD must become inactive 

within 24 engine hours of becoming 

active (or other period we approve in 

unusual circumstances). 

• The manufacturer must show that 

the AECD deactivate emission controls 

(such as inducement strategies) only to 

the extent necessary to address the 

expected emergency situation. 

(3) Allowable Use of Emergency AECDs 

This allowance is intended generally 

to address SCR-equipped engines 

operating in emergency situations when 

DEF is unavailable. In such cases, 

inducement strategies could result in a 

loss of power of the engine which could 

effectively prevent the equipment from 

functioning. Under this provision, a 

manufacturer could include a dormant 

feature in the engine’s control software 

that could be activated to disable 

inducement strategies. 

We are also proposing to allow this 

for other types of controls, where a 

manufacturer can clearly demonstrate 

that this relief could be needed. We are 

requesting comment about whether we 

should specifically identify such other 

controls or leave the regulatory text 

more open ended. 

Finally, we are requesting comment 

about the circumstances under which 

we should allow the AECD to be 

activated. Should emergency situations 

include only those circumstances where 

human life is at stake? Should it be 

allowed automatically whenever a 

federal disaster is declared? 

VII. Economic, Environmental, and 

Health Impacts of Proposed Rule 

A. Economic Impacts 

(1) Economic Impacts of Emergency 

Vehicle Proposal 

EPA expects the economic effects of 

this proposal to be small, and to 

potentially have benefits that are a 

natural result of easing constraints. 

(a) Costs to Manufacturers 

Due to the optional and voluntary 

nature of this proposal, there are no 

direct regulatory compliance costs to 

engine manufacturers. To the extent 

manufacturers elect to develop and 

deploy upgrades to engines for 

emergency vehicles, they may 

voluntarily incur some degree of costs 

associated with the following: 

• Design and testing to determine 

effectiveness of potential AECDs. 

• Education & outreach to 

intermediate vehicle manufacturers and 

end users. 

• Deployment of AECDs onto new 

and in-use emergency vehicles. 

• Labeling costs. 

EPA expects any fixed costs would be 

small, and any variable costs would 

apply only to the engines sold for 

installation in emergency vehicles or 

emergency equipment, which comprise 

less than one percent of the heavy-duty 

on-road fleet, and an even smaller 

fraction of the nonroad fleet. As per 

standard practice, manufacturers would 

be free to set a fair market price for any 

approved AECD or field modification 

they offer, to offset the costs incurred in 

its development. 

(b) Operational Costs 

Depending on the type of AECD or 

field modification that a manufacturer 

voluntarily elects to deploy, some 

operational costs could increase and 

some could decrease. 

(i) Maintenance and Warranty Costs 

When an emergency vehicle is 

experiencing frequent plugging of its 

DPF, this increases maintenance costs 

for owners and warranty costs for 

manufacturers. Maintenance costs can 

include service calls for a techniciancontrolled regeneration, towing fees 

where on-site regeneration cannot be 

achieved, and costs to deploy reserve 

vehicles while the impaired vehicle is 

being serviced. These costs are expected 

to decrease with this proposal, and are 

discussed further below. 

Manufacturers incur warranty costs 

when a vehicle under warranty must be 

returned for service. Because this 

proposed action would allow 

manufacturers the flexibility to improve 

the reliability of their engines, EPA 

expects warranty costs for emergency 

vehicles and engines in emergency 

vehicles would decrease as a result of 

this action. 

Should an AECD be deployed that 

allows manual active regenerations at 

more frequent intervals, this could 

increase the total number of 

regenerations, exposing the DPF 

substrate to more frequent thermal stress 

and general wear & tear. However, while 

it is expected that the frequency of 

regenerations would increase, the 

duration of each regeneration would 

decrease because the total soot loading 

of the DPF would likely remain 

unchanged or be reduced due to other 

control strategies within the approved 

AECD. Because manufacturers are held 

to strict standards related to the 

warranty, maintenance and durability of 

these systems, EPA expects that 

measures will be taken to ensure that 

any AECD that is deployed would not 

decrease the ash cleaning interval or 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
34170 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

38EPA prohibits engine manufacturers from 

requiring repair or replacement of particulate traps 

on heavy heavy-duty diesel engines more than once 

every 150,000 miles. 40 CFR 86.004–25(b)(4)(iii). 

39See memo dated May 4, 2012, ‘‘Fuel Use With 

Dosing for DPF Regeneration,’’ Docket ID EPA–HQ– 

OAR–2011–1032. 

40 ICCT, May 2009, ‘‘Heavy-Duty Vehicle Market 

Analysis: Vehicle Characteristics & Fuel Use, 

Manufacturer Market Shares.’’ 

otherwise decrease the durability of the 

emission control system.38

With this proposal, manufacturers 

would have the flexibility to design 

alternate calibrations to reduce soot 

loading to the DPF and extend the 

interval between regenerations. There 

would also be more flexibility to enable 

more passive and automatic active 

regenerations, which both expose the 

DPF to less thermal stress than do 

manual active regenerations. In 

summary, EPA does not expect any 

warranty or maintenance costs would 

increase due to this proposal, and it is 

very likely that these would decrease. 

Furthermore, EPA believes that the 

potential for reduced warranty costs 

may help to offset the cost to produce 

and deploy any optional AECDs. 

Similarly, EPA believes the potential for 

reduced maintenance and operational 

costs may offset the cost to owners for 

obtaining requested AECDs. 

(ii) Fuel Costs From Dosing 

Where DPF systems employ fuel 

dosing to enable active automatic 

regenerations, it is uncertain whether 

liberalizing the parameters for initiating 

regenerations would affect fuel 

consumption. Operators have reported 

that vehicles burn more fuel during 

regenerations, though the quantity 

varies among vehicles. 

Where automatic active regenerations 

employ fuel dosing, it is uncertain 

whether fuel consumption would 

increase with an increased number of 

regenerations during a given operating 

period. If all else were to remain the 

same, it is likely that the duration of 

each automatic active regeneration may 

be decreased. To the extent 

regenerations are enabled with other 

means besides fuel, or demand for 

regenerations is reduced through 

recalibration, then any potential 

increase in fuel use from dosing would 

be mitigated. 

As an illustration, we have estimated 

the additional fuel use for a truck with 

a dosing strategy where its regeneration 

interval is decreased from 25 hours to 

eight hours, due to the increased 

availability of operator-commanded 

regenerations. In this example, we 

assume a single regeneration consumes 

approximately half a gallon of 

supplemental fuel. If the vehicle has 

average engine operating hours of 1,200 

per year, then its number of 

regeneration events would increase from 

about 50 per year to 150 per year, under 

the above assumptions. If the amount of 

supplemental fuel use remained 

unchanged under the new regime (a 

conservative assumption) then 

potentially the vehicle could consume 

an additional 50 gallons of fuel per year 

from the increased frequency of 

regenerations alone. Considering current 

costs of ultra low sulfur diesel fuel, this 

could translate to about $200 per 

vehicle in additional annual fuel costs. 

As explained above, EPA does not 

believe this is a likely scenario, as the 

amount of fuel used per regeneration 

event would likely decrease with 

increasing frequency, and engine 

manufacturers would be likely to adjust 

combustion parameters to avoid placing 

additional thermal stress on the DPF. A 

more detailed analysis of fuel use and 

potential costs associated with dosing 

strategies is included in a memo to the 

docket associated with this 

rulemaking.39

(c) Societal Costs 

Because this proposal eases 

constraints on the development of 

robust DPF systems, the economic 

impacts can only improve with this 

action. It is presumed that the benefits 

to society of enabling first responders to 

act quickly when needed outweigh the 

costs to society of any temporary 

increase in emissions from this small 

segment of vehicles. 

(2) Economic Impacts of SCR 

Maintenance Proposal 

This action would codify previously 

published final agency actions regarding 

SCR maintenance intervals. No new 

regulatory burdens would be imposed. 

Rather, by codifying former decisions 

that were based on administrative 

petitions and of limited applicability, 

EPA is providing regulatory certainty 

that will allow affected manufacturers to 

plan their product development 

accordingly. 

(3) Economic Impacts for Nonroad 

Engines Used in Emergency Situations 

EPA expects the economic effects of 

this proposal to be small, and to 

potentially have benefits that are a 

natural result of easing constraints. Due 

to the optional and voluntary nature of 

this proposal, there are no direct 

regulatory compliance costs to engine 

manufacturers. To the extent 

manufacturers elect to develop and 

deploy upgrades to engines for 

emergency vehicles, they may 

voluntarily incur some degree of costs. 

We do not expect there to be any 

operator costs for this allowance, other 

than the potential cost associated with 

sending written confirmation of an 

emergency situation to the certificate 

holder. However, since this option 

would be activated rarely (or perhaps 

not at all), total costs to operators would 

be negligible. 

B. Environmental Impacts 

(1) Environmental Impacts of 

Emergency Vehicle Proposal 

We expect any environmental impacts 

from this proposal would be small. By 

promulgating these amendments, it is 

expected that the emissions from this 

segment of the heavy-duty fleet would 

not change significantly. 

(a) Fleet Characterization and Emission 

Inventory 

EPA estimates that on-road emergency 

vehicles comprise less than one percent 

of the national heavy-duty fleet. 

According to the International Council 

on Clean Transportation (ICCT), less 

than one percent of all new heavy-duty 

truck registrations in 2003 to 2007 were 

for emergency vehicles (includes class 8 

fire trucks plus other class 3–8 

emergency vehicles).40 On average, the 

ICCT’s data suggest that approximately 

5,700 new emergency vehicles are sold 

in the U.S. each year; about 0.8 percent 

of the 3.4 million new heavy-duty 

trucks registered between 2003 and 

2007. The available information 

indicates that the emergency vehicles 

included in the scope of this rulemaking 

have lower annual vehicle miles 

traveled than average non-emergency 

vehicles. Therefore, we conclude that 

they contribute less than 1% of the 

annual air emissions from the heavyduty diesel truck fleet. 

(b) Emission Impacts From Auxiliary 

Emission Control Devices on Emergency 

Vehicles 

Due to the optional and voluntary 

nature of this action, it is difficult to 

estimate its overall emissions impact 

accurately. The proposed amendments 

offer many options to manufacturers, 

and the emissions impacts will depend 

on which options and strategies are 

employed, and for how many vehicles. 

(i) NOX Emissions Impacts 

During both automatic active and 

manual active regenerations, emission 

rates increase for some pollutants, 

especially NOX when post-DPF aftertreatment devices are not present. The 


tkelley on DSK3SPTVN1PROD with PROPOSALS2
Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 34171 

41See memo dated May 4, 2012, ‘‘NOX Emissions 

from DPF Regeneration,’’ Docket ID EPA–HQ–OAR– 

2011–1032. 

42See NOX Memo, Note 41, above. 

43See Memo dated May 4, 2012, ‘‘PM Emissions 

Impacts,’’ Docket ID EPA–HQ–OAR–2011–1032. 

44See PM memo, Note 43, above. 45See Fuel Dosing Memo, Note 39, above. 

higher than normal combustion 

chamber temperatures during active 

regeneration with high rates of 

oxidation occurring across the catalyst 

can create conditions conducive to NOX

formation. From certification data for 

2008 model year engines, the difference 

between the NOX emission rate during 

normal operation and the rate during 

active regeneration can range from an 

undetectably small difference to a fivefold increase. The magnitude of the NOX

increase is only part of the story, 

however. As part of their certifications, 

engine manufacturers may provide 

frequency factors that adjust for the 

average excess emissions during DPF 

regeneration. As used in engine 

certification, the frequency factor 

indicates the percent of test cycles 

during which DPF regeneration is 

expected to occur. From certification 

data for 2008 and 2011 model year 

engines, DPF regeneration frequency 

factors for heavy-duty engines range 

from near zero to nearly 20 percent. 

Overall, the certification data indicate 

that the higher the increase in NOX

during a DPF regeneration event, the 

less often active regeneration occurs on 

that engine, especially over the transient 

test cycle. A summary of this 

information is presented in a memo to 

the docket associated with this 

rulemaking.41

As a result of this proposed action, it 

is possible that some engine 

manufacturers will submit applications 

for AECD’s with liberalized parameters 

under which automatic active and/or 

manual active regenerations may occur, 

for emergency vehicles. Under these 

liberalized parameters, several outcomes 

are possible, depending on the 

engineering design. While the NOX

emission rate during DPF regeneration 

could increase above the rate of the 

current certified configuration, it is also 

possible that the duration of each event 

could decrease. While the frequency of 

manual active regenerations could 

increase if the engine controls permitted 

operators to initiate parked regeneration 

at any soot loading, it is also possible 

the frequency of automatic or manual 

active regenerations could decrease with 

the new designs, making wider use of 

passive regeneration strategies. Given 

that it is difficult to estimate how 

popular each option may be, and what 

other actions may be taken to alter 

engines and/or emission control 

systems, EPA has provided examples of 

possible emission scenarios due to this 

proposal in a memo to the docket.42

(ii) PM Emissions Impacts 

In the comment letters EPA received 

urging swift action providing relief for 

emergency vehicles, it was often cited 

that the pollution from a structural fire 

is far worse than the tailpipe emissions 

of a fire truck. To provide some 

perspective on this, EPA is providing a 

brief discussion of PM emissions in this 

section. 

A rough method for estimating 

emissions from structural fires is 

obtained by multiplying a national 

average factor of 2.3 fires per 1,000 

residents by the national population, 

along with a PM emission factor of 10.8 

lb per ton burned, and an average fuel 

loading of 1.1 tons burned per fire. 

Using these estimates, EPA calculates 

just under 5,000 tons of PM is emitted 

in the U.S. each year from structural 

fires. A more detailed analysis of PM 

emissions from structural fires in 

relation to PM emissions from 

emergency vehicles is included in a 

memo to the docket associated with this 

rulemaking.43

We expect manufacturers who choose 

to develop optional AECDs for 

emergency vehicles to employ strategies 

that prevent the occurrence of abnormal 

conditions of the emission control 

system. Where preventive strategies 

alone are not demonstrated to be 

failsafe, EPA expects there may be 

instances where it is justified to provide 

engine exhaust backpressure relief, 

either mechanical or through other 

means. While we expect this will not be 

a widespread solution, there may be 

cases where a relief valve may be 

employed on a vehicle whose DPF 

became plugged frequently, allowing 

temporary emission control bypass to 

occur as a last resort to prevent engine 

failure. An example of possible PM 

emissions changes due to this proposal 

is presented in a memo to the docket 

associated with this rulemaking.44

(iii) Fuel Use From Dosing 

As described above in Section IV.C, 

only some control systems employ fuel 

dosing as a strategy to initiate active 

regeneration. In a memo to the docket 

associated with this rulemaking, EPA 

estimates the potential increase in fuel 

use due to more frequent operatorcommanded regenerations with dosing 

at an average of about 50 gallons per 

year per vehicle, if other measures to 

reduce the need for regenerations are 

not taken.45 The emissions associated 

with this supplemental fuel use are 

discussed above. EPA requests comment 

on the impact of this proposed action on 

fuel consumption in emergency vehicles 

whose active regeneration strategies 

include fuel dosing. 

(2) Environmental Impacts of SCR 

Maintenance Proposal 

EPA believes that the likelihood of 

emissions-related maintenance 

occurring in use would remain 

unchanged as a result of this action. 

Therefore, there are no anticipated 

adverse environmental impacts. 

(3) Environmental Impacts for Nonroad 

Engines Used in Emergency Situations 

EPA does not expect any significant 

environmental effects as a result this 

proposal. This option would be 

activated rarely (or perhaps not at all) 

and would only affect emissions for a 

very short period. 

C. Health Effects 

EPA’s clean diesel standards are 

already providing substantial benefits to 

public health and welfare and the 

environment through significant 

reductions in emissions of NOX, PM, 

nonmethane hydrocarbons (NMHC), 

carbon monoxide, sulfur oxides (SOX), 

and air toxics. We project that by 2030, 

the on-highway program alone will 

reduce annual emissions of NOX, 

NMHC, and PM by 2.6 million, 115,000 

and 109,000 tons, respectively. These 

emission reductions will prevent 8,300 

premature deaths, over 9,500 

hospitalizations, and 1.5 million work 

days lost. All told, the monetized 

benefits of the on-highway rule plus the 

nonroad diesel Tier 4 rule total over 

$150 billion. A sizeable part of the 

benefits in the early years of these 

programs has come from large 

reductions in the amount of direct and 

secondary PM emitted by the existing 

fleet of heavy-duty engines and 

vehicles, by requiring the use of the 

higher quality diesel fuel in these 

vehicles. While this proposed action 

may slightly increase some emissions, 

as explained in the previous section, we 

do not expect that these small increases 

will significantly diminish the health 

benefits of our stringent clean diesel 

standards. 

VIII. Public Participation 

We request comment by July 27, 2012 

on all aspects of this proposal. This 

section describes how you can 

participate in this process. 


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A. How do I submit comments? 

We are opening a formal comment 

period by publishing this document. We 

will accept comments through July 27, 

2012. If you have an interest in the 

program described in this document, we 

encourage you to comment on any 

aspect of this rulemaking. We request 

comment on various topics throughout 

this proposal. 

Your comments will be most useful if 

you include appropriate and detailed 

supporting rationale, data, and analysis. 

If you disagree with parts of the 

proposed program, we encourage you to 

suggest and analyze alternate 

approaches to meeting the goals 

described in this proposal. You should 

send all comments, except those 

containing proprietary information, to 

our Air Docket (see ADDRESSES) before 

the end of the comment period. 

If you submit proprietary information 

for our consideration, you should 

clearly separate it from other comments 

by labeling it ‘‘Confidential Business 

Information (CBI).’’ You should send 

CBI directly to the contact person listed 

under FOR FURTHER INFORMATION

CONTACT instead of the public docket. 

This will help ensure that no one 

inadvertently places proprietary 

information in the docket. If you want 

us to use your confidential information 

as part of the basis for the final rule, you 

should send a non-confidential version 

of the document summarizing the key 

data or information. We will disclose 

information covered by a claim of 

confidentiality only through the 

application of procedures described in 

40 CFR part 2. If you do not identify 

information as confidential when we 

receive it, we may make it available to 

the public without notifying you. 

EPA is also publishing a Direct Final 

Rule (DFR) addressing the emergency 

vehicle provisions described in Section 

IV of this document. If we receive 

adverse comments on the emergency 

vehicle provisions in this proposal by 

July 9, 2012, we will publish a timely 

withdrawal in the Federal Register 

informing the public that the direct final 

rule will not take effect, and we will 

complete the process of responding to 

comments and issuing a final rule. 

EPA is publishing the DFR to expedite 

the deployment of solutions that will 

best ensure the readiness of the nation’s 

emergency vehicles. We request that 

commenters identify in your comments 

any portions of the emergency vehicle 

proposed action described in Section IV 

above with which you agree and 

support as proposed, in addition to any 

comments regarding suggestions for 

improvement or provisions with which 

you disagree. In the case of a comment 

that is otherwise unclear whether it is 

adverse, EPA would interpret relevant 

comments calling for more flexibility or 

less restrictions for emergency vehicles 

as supportive of the direct final action. 

In this way, the EPA will be able to 

adopt those elements of the DFR that are 

fully supported and most needed today, 

while considering and addressing any 

adverse comments received on the 

proposed rule, in the course of 

developing the final rule. 

Note that Docket Number EPA–HQ– 

OAR–2011–1032 is being used for both 

the DFR and this Notice of Proposed 

Rulemaking (NPRM). 

B. Will there be a public hearing? 

We will hold a public hearing at the 

EPA’s National Vehicle and Fuels 

Emission Laboratory, 2565 Plymouth 

Road in Ann Arbor, Michigan on June 

27, 2012. The hearing will start at 

10:00 a.m. and continue until everyone 

has had a chance to speak. 

If you would like to present testimony 

at the public hearing, we ask that you 

notify the contact person listed above 

under FOR FURTHER INFORMATION

CONTACT at least ten days before the 

hearing. You should estimate the time 

you will need for your presentation and 

identify any needed audio/visual 

equipment. We suggest that you bring 

copies of your statement or other 

material for the EPA panel and the 

audience. It would also be helpful if you 

send us a copy of your statement or 

other materials before the hearing. 

We will make a tentative schedule for 

the order of testimony based on the 

notifications we receive. This schedule 

will be available on the morning of the 

hearing. In addition, we will reserve a 

block of time for anyone else in the 

audience who wants to give testimony. 

We will conduct the hearing informally, 

and technical rules of evidence won’t 

apply. We will arrange for a written 

transcript of the hearing and keep the 

official record of the hearing open for 30 

days to allow you to submit 

supplementary information. You may 

make arrangements for copies of the 

transcript directly with the court 

reporter. 

IX. Statutory and Executive Order 

Reviews 

A. Executive Order 12866: Regulatory 

Planning and Review and Executive 

Order 13563: Improving Regulation and 

Regulatory Review 

This action is not a ‘‘significant 

regulatory action’’ under the terms of 

Executive Order (EO) 12866 (58 FR 

51735, October 4, 1993) and is therefore 

not subject to review under Executive 

Orders 12866 and 13563 (76 FR 3821, 

January 21, 2011). 

B. Paperwork Reduction Act 

This action does not impose any new 

information collection burden. The 

proposed regulatory relief for emergency 

vehicles would be voluntary and 

optional, and the proposed revisions for 

engine and vehicle maintenance would 

merely codify existing guidelines. 

However, the Office of Management and 

Budget (OMB) has previously approved 

the information collection requirements 

contained in the existing regulations 

under the provisions of the Paperwork 

Reduction Act, 44 U.S.C. 3501 et seq. 

and has assigned OMB Control Numbers 

2060–0104 and 2060–0287. The OMB 

control numbers for EPA’s regulations 

in 40 CFR are listed in 40 CFR part 9. 

C. Regulatory Flexibility Act 

The Regulatory Flexibility Act (RFA) 

generally requires an agency to prepare 

a regulatory flexibility analysis of any 

rule subject to notice and comment 

rulemaking requirements under the 

Administrative Procedure Act or any 

other statute unless the agency certifies 

that the rule will not have a significant 

economic impact on a substantial 

number of small entities. Small entities 

include small businesses, small 

organizations, and small governmental 

jurisdictions. 

For purposes of assessing the impacts 

of this rule on small entities, small 

entity is defined as: (1) A small business 

primarily engaged in shipbuilding and 

repairing as defined by NAICS code 

336611 with 1,000 or fewer employees 

(based on Small Business 

Administration size standards); (2) a 

small business that is primarily engaged 

in freight or passenger transportation on 

the Great Lakes as defined by NAICS 

codes 483113 and 483114 with 500 or 

fewer employees (based on Small 

Business Administration size 

standards); (3) a small business 

primarily engaged in commercial and 

industrial machinery and equipment 

repair and maintenance as defined by 

NAICS code 811310 with annual 

receipts less than $7 million (based on 

Small Business Administration size 

standards); (4) a small governmental 

jurisdiction that is a government of a 

city, county, town, school district or 

special district with a population of less 

than 50,000; and (5) a small 

organization that is any not-for-profit 

enterprise which is independently 

owned and operated and is not 

dominant in its field. 

After considering the economic 

impacts of today’s proposed rule on 


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small entities, I certify that proposed 

rule would not have a significant 

economic impact on a substantial 

number of small entities. 

In determining whether a rule has a 

significant economic impact on a 

substantial number of small entities, the 

impact of concern is any significant 

adverse economic impact on small 

entities, since the primary purpose of 

the regulatory flexibility analyses is to 

identify and address regulatory 

alternatives ‘‘which minimize any 

significant economic impact of the rule 

on small entities.’’ 5 U.S.C. 603 and 604. 

Thus, an agency may certify that a rule 

will not have a significant economic 

impact on a substantial number of small 

entities if the rule relieves regulatory 

burden, or otherwise has a positive 

economic effect on all of the small 

entities subject to the rule. 

This proposed rule provides 

regulatory relief related to emergency 

vehicles and codifies existing guidelines 

related to engine and vehicle 

maintenance. As such, we anticipate no 

costs and therefore no regulatory burden 

associated with this rule. We have 

concluded that this rule will not 

increase regulatory burden for affected 

small entities. 

D. Unfunded Mandates Reform Act 

This proposal contains no Federal 

mandates under the regulatory 

provisions of Title II of the UMRA for 

State, local, or tribal governments. The 

proposal imposes no enforceable duty 

on any State, local or tribal 

governments. EPA has determined that 

this proposal contains no regulatory 

requirements that might significantly or 

uniquely affect small governments. The 

agency has determined that this 

proposal does not contain a Federal 

mandate that may result in expenditures 

of $100 million or more for the private 

sector in any one year. Manufacturers 

have the flexibility and will likely 

choose whether or not to use optional 

AECD’s based on their strategies for 

complying with the applicable 

emissions standards. Similarly, 

manufacturers may choose to use DEF 

maintenance intervals longer than the 

minimums proposed in this action, and 

manufacturers may elect to use SCR 

strategies that consume lower amounts 

of DEF. Thus, today’s proposal is not 

subject to the requirements of sections 

202 and 205 of the UMRA. 

E. Executive Order 13132: Federalism 

Executive Order 13132, entitled 

‘‘Federalism’’ (64 FR 43255, August 10, 

1999), requires EPA to develop an 

accountable process to ensure 

‘‘meaningful and timely input by State 

and local officials in the development of 

regulatory policies that have federalism 

implications.’’ ‘‘Policies that have 

federalism implications’’ is defined in 

the Executive Order to include 

regulations that have ‘‘substantial direct 

effects on the States, on the relationship 

between the national government and 

the States, or on the distribution of 

power and responsibilities among the 

various levels of government.’’ 

This proposed action does not have 

federalism implications. It will not have 

substantial direct effects on the States, 

on the relationship between the national 

government and the States, or on the 

distribution of power and 

responsibilities among the various 

levels of government, as specified in 

Executive Order 13132. This proposed 

rule would apply to manufacturers of 

heavy-duty diesel engines and not to 

state or local governments. Thus, 

Executive Order 13132 does not apply 

to this action. 

In the spirit of Executive Order 13132, 

and consistent with EPA policy to 

promote communications between the 

agency and State and local governments, 

the agency specifically solicits comment 

on this proposed action from State and 

local officials. 

F. Executive Order 13175: Consultation 

and Coordination With Indian Tribal 

Governments 

This action does not have tribal 

implications, as specified in Executive 

Order 13175 (65 FR 67249, November 9, 

2000). This proposal will be 

implemented at the Federal level and 

would impose compliance costs only on 

affected engine manufacturers 

depending on the extent to which they 

take advantage of the flexibilities 

offered. Tribal governments would be 

affected only to the extent they purchase 

and use vehicles with regulated engines. 

Thus, Executive Order 13175 does not 

apply to this proposed rule. EPA 

specifically solicits additional comment 

on this proposed action from tribal 

officials. 

G. Executive Order 13045: Protection of 

Children From Environmental Health 

and Safety Risks 

Executive Order 13045: ‘‘Protection of 

Children From Environmental Health 

Risks and Safety Risks’’ (62 FR 19885, 

April 23, 1997) applies to any rule that: 

(1) is determined to be ‘‘economically 

significant’’ as defined under Executive 

Order 12866, and (2) concerns an 

environmental health or safety risk that 

EPA has reason to believe may have a 

disproportionate effect on children. If 

the regulatory action meets both criteria, 

the agency must evaluate the 

environmental health or safety effects of 

the planned rule on children, and 

explain why the planned regulation is 

preferable to other potentially effective 

and reasonably feasible alternatives 

considered by the agency. 

EPA interprets Executive Order 13045 

as applying only to those regulatory 

actions that are based on health or safety 

risks, such that the analysis required 

under section 5–501 of the Order has 

the potential to influence the regulation. 

This proposed rule is not subject to 

Executive Order 13045 because it does 

not establish an environmental standard 

intended to mitigate health or safety 

risks. 

H. Executive Order 13211: Energy 

Effects 

This proposed action is not subject to 

Executive Order 13211 (66 FR 28355 

(May 22, 2001)), because it is not a 

significant regulatory action under 

Executive Order 12866. 

I. National Technology Transfer 

Advancement Act 

Section 12(d) of the National 

Technology Transfer and Advancement 

Act of 1995 (‘‘NTTAA’’), Public Law 

104–113, 12(d) (15 U.S.C. 272 note) 

directs EPA to use voluntary consensus 

standards in its regulatory activities 

unless to do so would be inconsistent 

with applicable law or otherwise 

impractical. Voluntary consensus 

standards are technical standards (e.g., 

materials, specifications, test methods, 

sampling procedures, and business 

practices) that are developed or adopted 

by voluntary consensus standards 

bodies. NTTAA directs EPA to provide 

Congress, through OMB, explanations 

when the Agency decides not to use 

available and applicable voluntary 

consensus standards. 

This action does not involve technical 

standards. Therefore, EPA is not 

considering the use of any voluntary 

consensus standards. 

J. Executive Order 12898: Federal 

Actions To Address Environmental 

Justice in Minority Populations and 

Low-Income Populations 

Executive Order 12898 (59 FR 7629 

(Feb. 16, 1994)) establishes federal 

executive policy on environmental 

justice. Its main provision directs 

federal agencies, to the greatest extent 

practicable and permitted by law, to 

make environmental justice part of their 

mission by identifying and addressing, 

as appropriate, disproportionately high 

and adverse human health or 

environmental effects of their programs, 

policies, and activities on minority 


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populations and low-income 

populations in the United States. 

EPA has determined that this 

proposed rule would not have 

disproportionately high and adverse 

human health or environmental effects 

on minority or low-income populations. 

This action is expected to increase the 

level of environmental protection for all 

affected populations because this 

proposed rule increases the ways that 

manufacturers can demonstrate 

compliance with heavy-duty engine 

standards. 

List of Subjects 

40 CFR Part 85 

Confidential business information, 

Imports, Labeling, Motor vehicle 

pollution, Reporting and recordkeeping 

requirements, Research, Warranties. 

40 CFR Part 86 

Administrative practice and 

procedure, Confidential business 

information, Motor vehicle pollution, 

Reporting and recordkeeping 

requirements. 

40 CFR Part 1039 

Environmental Protection, 

Administrative practice and procedure, 

Air pollution control, Confidential 

business information, Imports, Labeling, 

Penalties, Reporting and recordkeeping 

requirements, Warranties. 

Dated: May 23, 2012. 

Lisa P. Jackson, 

Administrator. 

For the reasons set forth in the 

preamble, the Environmental Protection 

Agency proposes to amend title 40, 

chapter I of the Code of Federal 

Regulations as follows: 

PART 85—CONTROL OF AIR 

POLLUTION FROM MOBILE SOURCES 

1. The authority citation for part 85 

continues to read as follows: 

Authority: 42 U.S.C. 7401–7671q. 

Subpart R—[Amended] 

2. Add § 85.1716 to subpart R to read 

as follows: 

§ 85.1716 Approval of an emergency 

vehicle field modification (EVFM). 

This section describes how you may 

implement design changes for an 

emergency vehicle that has already been 

placed into service to ensure that the 

vehicle will perform properly in 

emergency situations. This applies for 

any light-duty vehicle, light-duty truck, 

or heavy-duty vehicle meeting the 

definition of emergency vehicle in 40 

CFR 86.004–2 or 86.1803. In this 

section, ‘‘you’’ refers to the certifying 

manufacturer and ‘‘we’’ refers to the 

EPA Administrator and any authorized 

representatives. 

(a) You must notify us in writing of 

your intent to install or distribute an 

emergency vehicle field modification 

(EVFM). In some cases you may install 

or distribute an EVFM only with our 

advance approval, as specified in this 

section. 

(b) Include in your notification a full 

description of the EVFM and any 

documentation to support your 

determination that the EVFM is 

necessary to prevent the vehicle from 

losing speed, torque, or power due to 

abnormal conditions of its emission 

control system, or to prevent such 

abnormal conditions from occurring 

during operation related to emergency 

response. Examples of such abnormal 

conditions may include excessive 

exhaust backpressure from an 

overloaded particulate trap, or running 

out of diesel exhaust fluid for engines 

that rely on urea-based selective 

catalytic reduction. Your determination 

must be based on an engineering 

evaluation or testing or both. 

(c) You may need our advance 

approval for your EVFM, as follows: 

(1) Where the proposed EVFM is 

identical to an AECD we approved 

under this part for an engine family 

currently in production, no approval of 

the proposed EVFM is necessary. 

(2) Where the proposed EVFM is for 

an engine family currently in 

production but the applicable 

demonstration is based on an AECD we 

approved under this part for an engine 

family no longer in production, you 

must describe to us how your proposed 

EVFM differs from the approved AECD. 

Unless we say otherwise, your proposed 

EVFM is deemed approved 30 days after 

you notify us. 

(3) If we have not approved an EVFM 

comparable to the one you are 

proposing, you must get our approval 

before installing or distributing it. In 

this case, we may request additional 

information to support your 

determination under paragraph (b) of 

this section, as follows: 

(i) If we request additional 

information and you do not provide it 

within 30 days after we ask, we may 

deem that you have retracted your 

request for our approval; however, we 

may extend this deadline for submitting 

the additional information. 

(ii) We will deny your request if we 

determine that the EVFM is not 

necessary to prevent the vehicle from 

losing speed, torque, or power due 

abnormal conditions of the emission 

control system, or to prevent such 

abnormal conditions from occurring, 

during operation related to emergency 

response. 

(iii) Unless we say otherwise, your 

proposed EVFM is deemed approved 30 

days after we acknowledge that you 

have provided us with all the additional 

information we have specified. 

(4) If your proposed EVFM is deemed 

to be approved under paragraph (c)(2) or 

(3) of this section and we find later that 

your EVFM in fact does not meet the 

requirements of this section, we may 

require you to no longer install or 

distribute it. 

PART 86—CONTROL OF EMISSIONS 

FROM NEW AND IN-USE HIGHWAY 

VEHICLES AND ENGINES 

3. The authority citation for part 86 

continues to read as follows: 

Authority: 42 U.S.C. 7401–7671q. 

Subpart A—[Amended] 

4. Section 86.004–2 is amended as 

follows: 

a. By adding a definition for 

‘‘Ambulance’’ in alphabetical order. 

b. By revising the definition for 

‘‘Defeat device’’. 

c. By adding definitions for ‘‘Diesel 

exhaust fluid’’, ‘‘Emergency vehicle’’, 

and ‘‘Fire truck’’ in alphabetical order. 

§ 86.004–2 Definitions. 

* * * * * 

Ambulance has the meaning given in 

§ 86.1803. 

Defeat device means an auxiliary 

emission control device (AECD) that 

reduces the effectiveness of the 

emission control system under 

conditions which may reasonably be 

expected to be encountered in normal 

vehicle operation and use, unless: 

(1) Such conditions are substantially 

included in the applicable Federal 

emission test procedure for heavy-duty 

vehicles and heavy-duty engines 

described in subpart N of this part; 

(2) The need for the AECD is justified 

in terms of protecting the vehicle 

against damage or accident; 

(3) The AECD does not go beyond the 

requirements of engine starting; or 

(4) The AECD applies only for engines 

that will be installed in emergency 

vehicles, and the need is justified in 

terms of preventing the engine from 

losing speed, torque, or power due 

abnormal conditions of the emission 

control system, or in terms of preventing 

such abnormal conditions from 

occurring, during operation related to 

emergency response. Examples of such 

abnormal conditions may include 

excessive exhaust backpressure from an 

overloaded particulate trap, and running 


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out of diesel exhaust fluid for engines 

that rely on urea-based selective 

catalytic reduction. 

Diesel exhaust fluid (DEF) has the 

meaning given in § 86.1803. 

Emergency vehicle means a vehicle 

that is an ambulance or a fire truck. 

Fire truck has the meaning given in 

§ 86.1803. 

* * * * * 

5. Section 86.004–25 is amended as 

follows: 

a. By revising paragraph (b)(4) 

introductory text. 

b. By adding paragraph (b)(4)(v). 

c. By revising paragraph (b)(6)(i) 

introductory text and (b)(6)(i)(H). 

d. By adding paragraph (b)(6)(i)(I). 

§ 86.004–25 Maintenance. 

* * * * * 

(b) * * * 

(4) For diesel-cycle heavy-duty 

engines, emission-related maintenance 

in addition to or at shorter intervals 

than the following specified values will 

not be accepted as technologically 

necessary, except as provided in 

paragraph (b)(7) of this section: 

* * * * * 

(v) For engines that use selective 

catalytic reduction, the replenishment 

of diesel exhaust fluid shall occur 

according to the following schedule: 

(A) For heavy-duty engines in 

vocational vehicles such as dump 

trucks, concrete mixers, refuse trucks 

and similar applications that are 

typically centrally fueled, at an interval, 

in miles or hours of vehicle operation, 

that is no less than the vehicle’s fuel 

capacity. 

(B) For all other heavy-duty engines, 

at an interval, in miles or hours of 

vehicle operation, that is no less than 

twice the vehicle’s fuel capacity. 

* * * * * 

(6)(i) The following components are 

defined as critical emission-related 

components: 

* * * * * 

(H) Components comprising the 

selective catalytic reduction system 

(including diesel exhaust fluid tank). 

(I) Any other component whose 

primary purpose is to reduce emissions 

or whose failure would commonly 

increase emissions of any regulated 

pollutant without significantly 

degrading engine performance. 

* * * * * 

6. Section 86.0004–28 is amended by 

revising paragraph (i) introductory text 

to read as follows: 

§ 86.004–28 Compliance with emission 

standards. 

* * * * * 

(i) Emission results from heavy-duty 

engines equipped with exhaust 

aftertreatment may need to be adjusted 

to account for regeneration events. This 

provision only applies for engines 

equipped with emission controls that 

are regenerated on an infrequent basis. 

For the purpose of this paragraph (i), the 

term ‘‘regeneration’’ means an event 

during which emission levels change 

while the aftertreatment performance is 

being restored by design. Examples of 

regenerations are increasing exhaust gas 

temperature to remove sulfur from an 

adsorber or increasing exhaust gas 

temperature to oxidize PM in a trap. For 

the purpose of this paragraph (i), the 

term ‘‘infrequent’’ means having an 

expected frequency of less than once per 

transient test cycle. Calculation and use 

of adjustment factors are described in 

paragraphs (i)(1) through (5) of this 

section. If your engine family includes 

engines with one or more AECDs for 

emergency vehicle applications 

approved under paragraph (4) of the 

definition of ‘‘defeat device’’ in 

§ 86.004–2, do not consider additional 

regenerations resulting from those 

AECDs when calculating emission 

factors or frequencies under this 

paragraph (i). 

* * * * * 

7. Section 86.095–35 is amended by 

revising paragraph (a)(3)(iii)(O) to read 

as follows: 

§ 86.095–35 Labeling. 

(a) * * * 

(3) * * * 

(iii) * * * 

(O) For engines with one or more 

approved AECDs for emergency vehicle 

applications under paragraph (4) of the 

definition of ‘‘defeat device’’ in 

§ 86.004–2, the statement: ‘‘THIS 

ENGINE IS FOR INSTALLATION IN 

EMERGENCY VEHICLES ONLY.’’ 

* * * * * 

Subpart B—[Amended] 

8. Section 86.131–00 is amended by 

adding paragraph (g) to read as follows: 

§ 86.131–00 Vehicle preparation. 

* * * * * 

(g) You may disable any AECDs that 

have been approved solely for 

emergency vehicle applications under 

paragraph (4) of the definition of ‘‘defeat 

device’’ in § 86.004–2. The emission 

standards do not apply when any of 

these AECDs are active. 

Subpart N—[Amended] 

9. Section 86.1305–2010 is amended 

by adding paragraph (i) to read as 

follows: 

§ 86.1305–2010 Introduction; structure of 

subpart. 

* * * * * 

(i) You may disable any AECDs that 

have been approved solely for 

emergency vehicle applications under 

paragraph (4) of the definition of ‘‘defeat 

device’’ in § 86.004–2. The emission 

standards do not apply when any of 

these AECDs are active. 

10. Section 86.1370–2007 is amended 

by adding paragraph (h) to read as 

follows: 

§ 86.1370–2007 Not-To-Exceed test 

procedures. 

* * * * * 

(h) Emergency vehicle AECDs. If your 

engine family includes engines with one 

or more approved AECDs for emergency 

vehicle applications under paragraph (4) 

of the definition of ‘‘defeat device’’ in 

§ 86.004–2, the NTE emission limits do 

not apply when any of these AECDs are 

active. 

Subpart S—[Amended] 

11. Section 86.1803–01 is amended as 

follows: 

a. By adding a definition for 

‘‘Ambulance’’ in alphabetical order. 

b. By revising the definition for 

‘‘Defeat device’’. 

c. By adding definitions for ‘‘Diesel 

exhaust fluid’’, ‘‘Emergency vehicle’’, 

and ‘‘Fire truck’’ in alphabetical order. 

§ 86.1803–01 Definitions. 

* * * * * 

Ambulance means a vehicle used for 

emergency medical care that provides 

all of the following: 

(1) A driver’s compartment. 

(2) A patient compartment to 

accommodate an emergency medical 

services provider and one patient 

located on the primary cot so positioned 

that the primary patient can be given 

intensive life-support during transit. 

(3) Equipment and supplies for 

emergency care at the scene as well as 

during transport. 

(4) Safety, comfort, and avoidance of 

aggravation of the patient’s injury or 

illness. 

(5) Two-way radio communication. 

(6) Audible and visual traffic warning 

devices. 

* * * * * 

Defeat device means an auxiliary 

emission control device (AECD) that 

reduces the effectiveness of the 

emission control system under 

conditions which may reasonably be 

expected to be encountered in normal 

vehicle operation and use, unless: 

(1) Such conditions are substantially 

included in the Federal emission test 

procedure; 


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(2) The need for the AECD is justified 

in terms of protecting the vehicle 

against damage or accident; 

(3) The AECD does not go beyond the 

requirements of engine starting; or 

(4) The AECD applies only for 

emergency vehicles and the need is 

justified in terms of preventing the 

vehicle from losing speed, torque, or 

power due to abnormal conditions of 

the emission control system, or in terms 

of preventing such abnormal conditions 

from occurring, during operation related 

to emergency response. Examples of 

such abnormal conditions may include 

excessive exhaust backpressure from an 

overloaded particulate trap, and running 

out of diesel exhaust fluid for engines 

that rely on urea-based selective 

catalytic reduction. 

* * * * * 

Diesel exhaust fluid (DEF) means a 

liquid compound used in conjunction 

with selective catalytic reduction to 

reduce NOX emissions. Diesel exhaust 

fluid is generally understood to conform 

to the specifications of ISO 22241. 

* * * * * 

Emergency vehicle means a vehicle 

that is an ambulance or a fire truck. 

* * * * * 

Fire truck means a vehicle designed to 

be used under emergency conditions to 

transport personnel and equipment and 

to support the suppression of fires and 

mitigation of other hazardous situations. 

* * * * * 

12. Section 86.1807–01 is amended by 

adding paragraphs (h) and (i) to read as 

follows: 

§ 86.1807–01 Vehicle labeling. 

* * * * * 

(h) Vehicles powered by model year 

2007 through 2013 diesel-fueled engines 

must include permanent readily visible 

labels on the dashboard (or instrument 

panel) and near all fuel inlets that state 

‘‘Use Ultra Low Sulfur Diesel Fuel 

Only’’ or ‘‘Ultra Low Sulfur Diesel Fuel 

Only’’. 

(i) For vehicles with one or more 

approved AECDs for emergency vehicles 

under paragraph (4) of the definition of 

‘‘defeat device’’ in § 86.1803, include 

the following statement on the emission 

control information label: ‘‘THIS 

VEHICLE HAS A LIMITED EXEMPTION 

AS AN EMERGENCY VEHICLE.’’ 

13. Subpart S is amended by 

removing § 86.1807–07. 

§ 86.1807–07 [Removed] 

14. Section 86.1834–01 is amended as 

follows: 

a. By revising paragraph the 

introductory text of (b)(4). 

b. By adding paragraph (b)(4)(iii). 

c. By revising paragraph (b)(6)(i)(H). 

d. By adding paragraph (b)(6)(i)(I). 

§ 86.1834–01 Allowable maintenance. 

* * * * * 

(b) * * * 

(4) For diesel-cycle vehicles, 

emission-related maintenance in 

addition to, or at shorter intervals than 

the following will not be accepted as 

technologically necessary, except as 

provided in paragraph (b)(7) of this 

section: 

* * * * * 

(iii) For vehicles that use selective 

catalytic reduction, the replenishment 

of diesel exhaust fluid shall occur at an 

interval, in miles or hours of vehicle 

operation, that is no less than the 

scheduled oil change interval. 

* * * * * 

(6) * * * 

(i) * * * 

(H) Components comprising the 

selective catalytic reduction system 

(including diesel exhaust fluid tank). 

(I) Any other component whose 

primary purpose is to reduce emissions 

or whose failure would commonly 

increase emissions of any regulated 

pollutant without significantly 

degrading engine performance. 

* * * * * 

15. Section 86.1840–01 is amended by 

revising paragraph (c) to read as follows: 

§ 86.1840–01 Special test procedures. 

* * * * * 

(c) Manufacturers of vehicles 

equipped with periodically regenerating 

aftertreatment devices must propose a 

procedure for testing and certifying such 

vehicles, including SFTP testing, for the 

review and approval of the 

Administrator. The manufacturer must 

submit its proposal before it begins any 

service accumulation or emission 

testing. The manufacturer must provide 

with its submittal sufficient 

documentation and data for the 

Administrator to fully evaluate the 

operation of the aftertreatment devices 

and the proposed certification and 

testing procedure. 

* * * * * 

PART 1039—CONTROL OF EMISSIONS 

FROM NEW AND IN-USE NONROAD 

COMPRESSION-IGNITION ENGINES 

16. The authority citation for part 

1039 continues to read as follows: 

Authority: 42 U.S.C. 7401–7671q. 

Subpart B—[Amended] 

17. Section 1039.115 is amended by 

adding paragraphs (g)(4) and (5) to read 

as follows: 

§ 1039.115 What other requirements 

apply? 

* * * * * 

(g) * * * 

(4) The auxiliary emission control 

device applies only for engines that will 

be installed in emergency equipment 

and the need is justified in terms of 

preventing the equipment from losing 

speed or power due to abnormal 

conditions of the emission control 

system, or in terms of preventing such 

abnormal conditions from occurring, 

during operation related to emergency 

response. Examples of such abnormal 

conditions may include excessive 

exhaust backpressure from an 

overloaded particulate trap, and running 

out of diesel exhaust fluid for engines 

that rely on urea-based selective 

catalytic reduction. The emission 

standards do not apply when any 

AECDs approved under this paragraph 

(g)(4) are active. 

(5) The auxiliary emission control 

device operates only in emergency 

situations as defined in § 1039.665 and 

meets all of the requirements of that 

section, and you meet all of the 

requirements of that section. 

18. Section 1039.125 is amended by 

adding paragraphs (a)(2)(iii) and 

(a)(3)(iii) to read as follows: 

§ 1039.125 What maintenance instructions 

must I give to buyers? 

* * * * * 

(a) * * * 

(2) * * * 

(iii) For SCR systems, the minimum 

interval for replenishing the diesel 

exhaust fluid is the number of engine 

operating hours necessary to consume a 

full tank of fuel based on normal usage 

starting from full fuel capacity for the 

equipment. 

(3) * * * 

(iii) For SCR systems, the minimum 

interval for replenishing the diesel 

exhaust fluid is the number of engine 

operating hours necessary to consume a 

full tank of fuel based on normal usage 

starting from full fuel capacity for the 

equipment. 

* * * * * 

19. Section 1039.130 is amended by 

revising paragraph (b)(3) to read as 

follows: 

§ 1039.130 What installation instructions 

must I give to equipment manufacturers? 

* * * * * 

(b) * * * 

(3) Describe the instructions needed 

to properly install the exhaust system 

and any other components. Include 

instructions consistent with the 

requirements of § 1039.205(u). Also 

describe how to properly size diesel 


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exhaust fluid reservoirs consistent with 

the specifications in § 1039.125(a) if 

applicable. 

* * * * * 

20. Section 1039.135 is amended by 

adding paragraph (c)(15) to read as 

follows: 

§ 1039.135 How must I label and identify 

the engines I produce? 

* * * * * 

(c) * * * 

(15) For engines with one or more 

approved auxiliary emission control 

devices for emergency equipment 

applications under § 1039.115(g)(4), the 

statement: ‘‘THIS ENGINE IS FOR 

INSTALLATION IN EMERGENCY 

EQUIPMENT ONLY.’’ 

* * * * * 

Subpart F—[Amended] 

21. Section 1039.501 is amended by 

adding paragraph (g) to read as follows: 

§ 1039.501 How do I run a valid emission 

test? 

* * * * * 

(g) You may disable any AECDs that 

have been approved solely for 

emergency equipment applications 

under § 1039.115(g)(4). 

22. Section 1039.525 is amended by 

revising the introductory text to read as 

follows: 

§ 1039.525 How do I adjust emission levels 

to account for infrequently regenerating 

aftertreatment devices? 

This section describes how to adjust 

emission results from engines using 

aftertreatment technology with 

infrequent regeneration events. For this 

section, ‘‘regeneration’’ means an 

intended event during which emission 

levels change while the system restores 

aftertreatment performance. For 

example, exhaust gas temperatures may 

increase temporarily to remove sulfur 

from adsorbers or to oxidize 

accumulated particulate matter in a 

trap. For this section, ‘‘infrequent’’ 

refers to regeneration events that are 

expected to occur on average less than 

once over the applicable transient duty 

cycle or ramped-modal cycle, or on 

average less than once per typical mode 

in a discrete-mode test. If your engine 

family includes engines with one or 

more AECDs for emergency equipment 

applications approved under 

§ 1039.115(g)(4), do not consider 

additional regenerations resulting from 

those AECDs when calculating emission 

factors or frequencies under this section. 

* * * * * 

Subpart G—[Amended] 

23. Add § 1039.665 to subpart G to 

read as follows: 

§ 1039.665 Special provisions for use of 

engines in emergency situations. 

This section specifies provisions that 

allow for AECDs that are necessary to 

ensure proper functioning of engines 

and equipment regulated under this part 

in emergency situations. For purposes of 

this section, an emergency situation is 

one in which the functioning (or 

malfunctioning) of emission controls 

poses a significant risk to human life. 

For example, a situation in which a 

feature of emission controls inhibits the 

performance of an engine being used to 

rescue a person from a life-threatening 

situation would be an emergency 

situation. AECDs approved under this 

section are not defeat devices. 

(a) Manufacturers may ask for 

approval under this section at any time; 

however, we encourage manufacturers 

to obtain preliminary approval before 

submitting an application for 

certification. We may allow 

manufacturers to apply an approved 

emergency AECD to engines and 

equipment that have already been 

placed into service. 

(b) We will approve an AECD where 

we determine the following criteria are 

met: 

(1) Activation of the AECD cannot 

occur without the specific permission of 

the certificate holder, and must require 

the input of a temporary code or 

equivalent security feature. 

(2) The AECD must become inactive 

within 24 engine hours of becoming 

active. 

(3) The AECD may deactivate 

emission controls as necessary to 

address the emergency situation. For 

purposes of this paragraph (b)(3), 

inducement strategies related to 

operating SCR-equipped engines 

without reductant are considered to be 

emission controls. 

(4) The AECD’s design is consistent 

with good engineering judgment. 

(c) The certificate holder must keep 

records to document requests for and 

use of emergency AECDs under this 

section. 

(1) The operator (or other person 

responsible for the engine/equipment) 

must send a written request to the 

certificate holder prior to use, or a 

written confirmation of a verbal request 

within 30 days of making the request, 

including a description of the 

emergency situation, the reason for the 

use of the AECD, and a signature from 

an official acknowledging the 

conditions of the emergency situation 

(such as a county sheriff, fire marshal, 

or hospital administrator). Such 

requests are deemed to be submissions 

to EPA. Where written confirmation is 

not submitted by the operator, we will 

deem operation of the engine with an 

activated emergency AECD to be a 

violation of 40 CFR 1068.101(b)(1). 

(2) If the operator does not submit the 

applicable confirmation within 30 days, 

the certificate holder must send written 

notification to the operator that failure 

to submit written confirmation may 

subject the operator to penalties under 

40 CFR 1068.101. 

(3) Within 60 days of the end of each 

calendar year in which the certificate 

holder authorizes use of the AECD, the 

certificate holder must send a report to 

the Designated Compliance Officer to 

summarize such use, including a 

description of the emergency situation 

precipitating each use, and copies of the 

written confirmation provided by 

operators (or statements that the 

operator did not provide confirmation). 

We may require more frequent reporting 

if we find that the certificate holder 

does not collect or attempt to collect 

written confirmation for each situation. 

(d) We may set other reasonable 

conditions to ensure that this provision 

is not used to circumvent the emission 

standards of this part. 

24. Add § 1039.670 to subpart G to 

read as follows: 

§ 1039.670 Approval of an emergency 

equipment field modification (EEFM). 

This section describes how you may 

implement design changes for 

emergency equipment that has already 

been placed into service to ensure that 

the equipment will perform properly in 

emergency situations. 

(a) You must notify us in writing of 

your intent to install or distribute an 

emergency equipment field 

modification (EEFM). In some cases you 

may install or distribute an EEFM only 

with our advance approval, as specified 

in this section. 

(b) Include in your notification a full 

description of the EEFM and any 

documentation to support your 

determination that the EEFM is 

necessary to prevent the equipment 

from losing speed, torque, or power due 

to abnormal conditions of its emission 

control system, or to prevent such 

abnormal conditions from occurring 

during operation related to emergency 

response. Examples of such abnormal 

conditions may include excessive 

exhaust backpressure from an 

overloaded particulate trap, or running 

out of diesel exhaust fluid (DEF) for 

engines that rely on urea-based selective 

catalytic reduction. Your determination 


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34178 Federal Register / Vol. 77, No. 111 / Friday, June 8, 2012 / Proposed Rules 

must be based on an engineering 

evaluation or testing or both. 

(c) You may need our advance 

approval for your EEFM, as follows: 

(1) Where the proposed EEFM is 

identical to an AECD we approved 

under this part for an engine family 

currently in production, no approval of 

the proposed EEFM is necessary. 

(2) Where the proposed EEFM is for 

an engine family currently in 

production but the applicable 

demonstration is based on an AECD we 

approved under this part for an engine 

family no longer in production, you 

must describe to us how your proposed 

EEFM differs from the approved AECD. 

Unless we say otherwise, your proposed 

EEFM is deemed approved 30 days after 

you notify us. 

(3) If we have not approved an EEFM 

comparable to the one you are 

proposing, you must get our approval 

before installing or distributing it. In 

this case, we may request additional 

information to support your 

determination under paragraph (b) of 

this section, as follows: 

(i) If we request additional 

information and you do not provide it 

within 30 days after we ask, we may 

deem that you have retracted your 

request for our approval; however, we 

may extend this deadline for submitting 

the additional information. 

(ii) We will deny your request if we 

determine that the EEFM is not 

necessary to prevent the equipment 

from losing speed, torque, or power due 

abnormal conditions of the emission 

control system, or to prevent such 

abnormal conditions from occurring, 

during operation related to emergency 

response. 

(iii) Unless we say otherwise, your 

proposed EEFM is deemed approved 30 

days after we acknowledge that you 

have provided us with all the additional 

information we have specified. 

(4) If your proposed EEFM is deemed 

to be approved under paragraph (c)(2) or 

(3) of this section and we find later that 

your EEFM in fact does not meet the 

requirements of this section, we may 

require you to no longer install or 

distribute it. 

Subpart I—[Amended] 

25. Section 1039.801 is amended by 

adding definitions for ‘‘Diesel exhaust 

fluid’’ and ‘‘Emergency equipment’’ in 

alphabetical order to read as follows: 

§ 1039.801 What definitions apply to this 

part? 

* * * * * 

Diesel exhaust fluid (DEF) means a 

liquid compound used in conjunction 

with selective catalytic reduction to 

reduce NOX emissions. Diesel exhaust 

fluid is generally understood to conform 

to the specifications of ISO 22241. 

* * * * * 

Emergency equipment means either 

of the following types of equipment: 

(1) Specialized vehicles used to 

perform aircraft rescue and fire-fighting 

functions at airports, with particular 

emphasis on saving lives and reducing 

injuries coincident with aircraft fires 

following impact or aircraft ground 

fires. 

(2) Wildland fire apparatus, which 

includes any apparatus equipped with a 

slip-on fire-fighting module, designed 

primarily to support wildland fire 

suppression operations. 

* * * * * 

26. Section 1039.805 is amended by 

adding abbreviations for ‘‘DEF’’, 

‘‘EEFM’’, ‘‘ISO’’, and ‘‘SCR’’ in 

alphabetical order to read as follows: 

§ 1039.805 What symbols, acronyms, and 

abbreviations does this part use? 

* * * * * 

DEF Diesel exhaust fluid. 

EEFM Emergency equipment field 

modification. 

* * * * * 

ISO International Organization for 

Standardization (see www.iso.org). 

* * * * * 

SCR Selective catalytic reduction. 

* * * * * 

[FR Doc. 2012–13087 Filed 6–7–12; 8:45 a.m.] 

BILLING CODE 6550–50–P 


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