Global Technical Regulation No. 19

Name:Global Technical Regulation No. 19
Description:Evaporative Emission Test Procedure for the Worldwide Harmonized Light Vehicle Test Procedure (WLTP EVAP).
Official Title:Global Technical Regulation on the Evaporative Emission Test Procedure for the Worldwide Harmonized Light Vehicle Test Procedure (WLTP EVAP).
Country:ECE - United Nations
Date of Issue:2017-08-25
Amendment Level:Amendment 3 of October 9, 2020
Number of Pages:50
Vehicle Types:Bus, Car, Light Truck
Subject Categories:Emissions and Fuel Consumption
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Keywords:

fuel, vehicle, test, tank, annex, temperature, system, canister, evaporative, paragraph, enclosure, pressure, carbon, procedure, emissions, emission, hydrocarbon, volume, vehicles, sealed, gtr, manufacturer, ambient, air, chamber, measured, diurnal, requirements, paragraphs, calibration, soak, type, time, reference, loss, vapour, hot, loading, means, depressurisation, mass, authority, responsible, control, wltp, puff, measurement, purge, capacity, technical

Text Extract:

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ECE/TRANS/180/Add.19/Amend.3
October 9, 2020
GLOBAL REGISTRY
Created on November 18, 2004, Pursuant to Article 6 of the
AGREEMENT CONCERNING THE ESTABLISHING OF GLOBAL TECHNICAL
REGULATIONS FOR WHEELED VEHICLES, EQUIPMENT AND PARTS WHICH
CAN BE FITTED AND/OR BE USED ON WHEELED VEHICLES
(ECE/TRANS/132 and Corr.1)
DONE AT GENEVA ON JUNE 25, 1998
Addendum 19:
UN GLOBAL TECHNICAL REGULATION No. 19
UN GLOBAL TECHNICAL REGULATION ON THE EVAPORATIVE EMISSION TEST
PROCEDURE FOR THE WORLDWIDE HARMONIZED LIGHT VEHICLE TEST PROCEDURE
(WLTP EVAP)
(ESTABLISHED IN THE GLOBAL REGISTRY ON JUNE 21, 2017)
Incorporating:
Amendment 1
dated September 20, 2018
Amendment 2
dated September 24, 2019
Amendment 3
dated October 9, 2020

UN GLOBAL TECHNICAL REGULATION No. 19
UN GLOBAL TECHNICAL REGULATION ON THE EVAPORATIVE EMISSION TEST
PROCEDURE FOR THE WORLDWIDE HARMONIZED LIGHT VEHICLE TEST
PROCEDURE (WLTP EVAP)
I. STATEMENT OF TECHNICAL RATIONALE AND JUSTIFICATION
A. INTRODUCTION
1. The compliance with emission standards is a central issue of vehicle certification worldwide.
Emissions comprise criteria pollutants having a direct (mainly local) negative impact on
health and environment, as well as pollutants having a negative environmental impact on a
global scale. Regulatory emission standards typically are complex documents, describing
measurement procedures under a variety of well-defined conditions, setting limit values for
emissions, but also defining other elements such as the durability and on-board monitoring
of emission control devices.
2. Most manufacturers produce vehicles for a global clientele or at least for several regions.
Albeit vehicles are not identical worldwide since vehicle types and models tend to cater to
local tastes and living conditions, the compliance with different emission standards in each
region creates high burdens from an administrative and vehicle design point of view. Vehicle
manufacturers, therefore, have a strong interest in harmonizing vehicle emission test
procedures and performance requirements as much as possible on a global scale.
Regulators also have an interest in global harmonization since it offers more efficient
development and adaptation to technical progress, potential collaboration at market
surveillance and facilitates the exchange of information between authorities.
3. As a consequence, stakeholders launched the work on the Worldwide harmonized Light
vehicle Test Procedure (WLTP) which aims at harmonizing emission-related test procedures
for light duty vehicles to the extent this is possible. One of the aspects covered within the
mandate for WLTP is the evaporative emission test procedure.
4. Evaporative emissions from vehicles is a complex phenomenon which depends on multiple
factors, that range from climate conditions to fuel properties, from driving and parking
patterns to the technology used to control these emissions.
5. Evaporative emissions from a vehicle can be defined, in a very generic way, as Volatile
Organic Compounds (VOCs) emitted by the vehicle itself in different operating conditions
but not directly derived from the combustion process. In petrol vehicles the most important
potential source of evaporative emissions is the loss of fuel through the evaporation and
permeation mechanisms from the fuel storing system. Fuel-related evaporative emissions
may occur during any vehicle operation including parking events, normal driving and vehicle
refuelling.
6. VOCs may also be emitted by specific components of the vehicle such as tyres, interior trim,
plastics or by other fluids (e.g. windshield washer fluid). These non-fuel related emissions
are usually quite low, not dependent on how the vehicle is used or on the quality of the fuel,
and tend to decrease over time. Evaporative emissions in general do not represent a
significant problem for diesel vehicles due to the very low vapour pressure of diesel fuel.

13. Another important source of evaporative emissions is the refuelling operation. When liquid
fuel is delivered into the tank the air/petrol vapour mixture present in the tank is displaced
and may be released into the atmosphere. Refuelling emissions are partially controlled
through the maximum allowed fuel vapour pressure by reducing its value during the hot
season. In addition, evaporative emissions during the refuelling operation can be controlled
in two different ways. One method is the so-called "Stage II" vapour recovery system. The
fuel nozzle is designed to draw the air/petrol vapour mixture displaced by the liquid fuel
entering the tank and route it to the underground petrol storage tank of the service station.
An alternative method is an "On-board Vapour Recovery System" (ORVR), which forces the
displaced vapours to be routed to the carbon canister instead of escaping from the refuelling
port.
14. An unintended source of HC emissions may occur from leaks in the system. Leaks may
occur in the vapour and/or the liquid system as a result of deterioration and/or faulty
operations. Examples of deterioration are corrosion of metallic components (e.g. fuel lines,
tanks), cracking of rubber hoses, hardening of seals, mechanical failures. On-board
diagnostic systems have been developed to check the integrity of the fuel system and are
required in some regions.
15. In the existing regional type approval procedures, the various situations that can lead to
significant evaporative emissions have been addressed either by developing different tests
or by adopting different measures. As an example, in certain regions refuelling emissions
are controlled by mandating the use of the Stage II vapour recovery system while in other
regions the ORVR approach has been chosen.
16. The need to represent real driving conditions as much as possible to make the performance
of vehicles at certification and in real life comparable puts therefore some limitations on the
level of harmonization to be achieved since, for instance, ambient temperatures vary widely
on a global scale while other potential sources of evaporative emissions are addressed in
different ways across the regions (e.g. refuelling emissions or potential leaks).
17. At this time, the WLTP EVAP test procedure focuses only on the evaporative emissions that
can occur during parking events. Running losses and refuelling emissions are out of the
scope of the current WLTP EVAP procedure. However, the venting of vapour from a sealed
tank immediately prior to refuelling (also known as depressurisation puff loss emissions) is
within the scope of this procedure.
18. The purpose of a UN Global Technical Regulation (UN GTR) is its implementation into
regional legislation by as many Contracting Parties as possible. However, the scope of
regional legislations in terms of vehicle categories concerned depends on regional
conditions and cannot be predicted for the time being. On the other hand, according to the
rules of the 1998 Agreement, Contracting Parties implementing a UN GTR must include all
equipment falling into the formal UN GTR scope. Care must be taken so that an unduly
large formal scope of the UN GTR does not prevent its regional implementation. Therefore,
the formal scope of this UN GTR is kept mainly for light duty vehicles. However, this
limitation of the formal UN GTR scope does not indicate that it could not be applied to a
larger group of vehicle categories by regional legislation. In fact, Contracting Parties are
encouraged to extend the scope of regional implementations of this UN GTR if this is
technically, economically and administratively appropriate.

C. BACKGROUND ON TEST PROCEDURES
24. For the development of the WLTP EVAP test procedure, the EVAP Task Force took into
account existing legislation as well as the recent review and revision of the European
evaporative emission test procedure.
25. The WLTP evaporative emission test procedure focuses only on evaporative emissions that
can occur during parking events from vehicles with petrol-fuelled engines (including bi-fuel
gas vehicles and hybrid vehicles combining an electric motor with a petrol-fuelled engine).
26. The WLTP evaporative emission test procedure is designed to measure evaporative
emissions from a parked vehicle using a sealed housing for evaporative emissions
determination (SHED). Two specific situations are considered:
(a)
(b)
Evaporative emissions occurring immediately after the end of a trip due to residual
fuel tank heating and the high temperatures of the engine and fuel system (hot soak
test);
Evaporative emissions occurring during a simulated extended parking event (48h)
while the vehicle is exposed to temperature fluctuations according to a specific profile.
This is intended to represent the temperature profile of a hot day (diurnal test). The
result of the diurnal test is represented by the total amount of VOCs released in the
SHED over a 48h period.
For sealed fuel tank systems, two other situations are addressed by the WLTP
evaporative emission test procedure:
(c)
(d)
Evaporative emissions that may occur if there is the need to depressurise the fuel
tank system before refuelling to ensure a safe operation. In order to reduce the
pressure inside the tank, the air/fuel vapours mixture released through the pressure
relief valve are stored in the canister(s). This operation should also avoid excessive
evaporative emissions through the filler neck when the fuel cap/fuel lid is opened.
This latter aspect requires that inside the tank there is very limited overpressure
compared to the ambient pressure when the fuel cap (or any alternative system used
to close the filler neck) is opened.
Evaporative emissions that may occur when the pressure inside the system exceed
the fuel tank relief pressure. The pressure relief valve opens to avoid the risk of a
rupture of the system. In these conditions the emissions could be uncontrolled in the
case of a fully saturated canister. This has been taken in to account when developing
the test procedure in order to reduce the frequency of this possibility or, alternatively,
to control these emissions by means of the carbon canister.
27. The performance of the evaporative emission control system strongly depends on the initial
condition of the carbon canister which is expected to adsorb the vapours generated in the
tank. In order to simulate realistic conditions, prior to starting the hot soak and diurnal tests,
the carbon canister is loaded to breakthrough and then purged by driving the vehicle over a
specific combination of WLTC sections (conditioning drive). The conditioning drive cycle
was extensively assessed and discussed also on the basis of real world activity data to take
into account that the most critical conditions are represented by short trips in urban areas.
For this reason, the conditioning drive for Class 2 and 3 vehicles includes one low phase,
two medium phases and one high phase. The extra-high phase was excluded. The
conditioning drive for Class 1 vehicles includes four low phases, two medium phases.

II.
TEXT OF THE GLOBAL TECHNICAL REGULATION
1. PURPOSE
This UN Global Technical Regulation (UN GTR) aims at providing a worldwide
harmonized method to determine the levels of evaporative emission from light-duty
vehicles in a repeatable and reproducible manner designed to be representative of real
world vehicle operation. The results will provide the basis for the regulation of these
vehicles within regional type approval and certification procedures.
2. SCOPE AND APPLICATION
This UN GTR applies to vehicles of Categories 1-2 and 2, both having a technically
permissible maximum laden mass not exceeding 3,500kg, with engines fuelled with
petrol , and to all vehicles of Category 1-1 with engines fuelled with petrol . At the
option of the Contracting Party, mono-fuel gas vehicles may be excluded.
3. DEFINITIONS
3.1. Test Equipment
3.1.1. "Accuracy" means the difference between a measured value and a reference value,
traceable to a national standard and describes the correctness of a result.
3.1.2. "Calibration" means the process of setting a measurement system's response so that
its output agrees with a range of reference signals.
3.2. Hybrid Electric Vehicles
3.2.1. "Charge-depleting operating condition" means an operating condition in which the
energy stored in the Rechargeable Electric Energy Storage System (REESS) may
fluctuate but decreases on average while the vehicle is driven until transition to
charge-sustaining operation.
3.2.2. "Charge-sustaining operating condition" means an operating condition in which the
energy stored in the REESS may fluctuate but, on average, is maintained at a neutral
charging balance level while the vehicle is driven.
3.2.3. "Not Off-vehicle Charging Hybrid Electric Vehicle" (NOVC-HEV) means a hybrid
electric vehicle that cannot be charged from an external source.
3.2.4. "Off-vehicle Charging Hybrid Electric Vehicle" (OVC-HEV) means a hybrid electric
vehicle that can be charged from an external source.
3.2.5. "Hybrid Electric Vehicle" (HEV) means a hybrid vehicle where one of the propulsion
energy converters is an electric machine.
3.2.6. "Hybrid Vehicle" (HV) means a vehicle equipped with a powertrain containing at least
two different categories of propulsion energy converters and at least two different
categories of propulsion energy storage systems.

4. ABBREVIATIONS
General abbreviations
BWC
PF
APF
OVC-HEV
NOVC-HEV
WLTC
REESS
CoP
SHED
Butane working capacity
Permeability factor
Assigned permeability factor
Off-vehicle charging hybrid electric vehicle
Not off-vehicle charging hybrid electric vehicle
Worldwide light-duty test cycle
Rechargeable electric energy storage system
Conformity of production
Sealed housing evaporative determination
5. GENERAL REQUIREMENTS
5.1. The vehicle and its components liable to affect the evaporative emissions shall be
designed, constructed and assembled so as to enable the vehicle in normal use and
under normal conditions of use such as humidity, rain, snow, heat, cold, sand, dirt,
vibrations, wear, etc. to comply with the provisions of this UN GTR during its useful life
determined by Contracting Parties.
5.1.1. This shall include the security of all hoses, joints and connections used within the
evaporative emission control systems.
5.1.2. For vehicles with a sealed fuel tank system, this shall also include having a system
which, just before refuelling, releases the tank pressure exclusively through a carbon
canister which has the sole function of storing fuel vapour. This ventilation route shall
also be the only one used when the tank pressure exceeds its safe working pressure.
5.2. The test vehicle shall be selected in accordance with Paragraph 5.5.2. of this UN GTR.
5.3. Vehicle Testing Condition
5.3.1. The types and amounts of lubricants and coolant for emissions testing shall be as
specified for normal vehicle operation by the manufacturer.
5.3.2. The type of fuel for testing shall be as specified in Annex 2 to this UN GTR.
5.3.3. All evaporative emissions controlling systems shall be in working order.
5.3.4. The use of any defeat device is prohibited.

5.5.2. The vehicle shall be considered to produce worst-case evaporative emissions and shall
be used for testing if it has the largest ratio of fuel tank capacity to BWC300 within the
family. The vehicle selection shall be agreed in advance with the responsible authority.
5.5.3. The use of any innovative system calibration, configuration, or hardware related to the
evaporative control system shall place the vehicle model in a different family.
5.6. The responsible authority shall not grant type approval if the information provided is
insufficient to demonstrate that the evaporative emissions are effectively limited during
the normal use of the vehicle.
5.7. Conformity of Production
At the option of the Contracting Party, the procedure for checking the conformity of a
vehicle for the Type 4 test is specified in Annex 3 to this UN GTR.
6. PERFORMANCE REQUIREMENTS
6.1. Limit Values
The following limit values shall apply:
(a)
(b)
For Contracting Parties which adopt the calculation defined in Paragraph 7.2. of
Annex 1, the limit value shall be 2.0g/test;
For Contracting Parties which adopt the alternative calculation defined in
Paragraph 7.3. of Annex 1, the limit value shall be determined by the Contracting
Party.

4.2. Evaporative Emission Measurement Enclosure
The evaporative emission measurement enclosure shall be a gas-tight rectangular
measuring chamber able to contain the vehicle under test. The vehicle shall be accessible
from all sides and the enclosure when sealed shall be gas-tight in accordance with
Paragraph 4.2.3.3. of this Annex. The inner surface of the enclosure shall be impermeable
and non-reactive to hydrocarbons. The temperature conditioning system shall be capable of
controlling the internal enclosure air temperature to follow the prescribed temperature
versus time profile throughout the test, and an average tolerance of 1°C over the duration of
the test.
The control system shall be tuned to provide a smooth temperature pattern that has a
minimum of overshoot, hunting, and instability about the desired long-term ambient
temperature profile. Interior surface temperatures shall not be less than 5°C nor more than
55°C at any time during the diurnal emission test.
Wall design shall be such as to promote good dissipation of heat. Interior surface
temperatures shall not be below 20°C, nor above 52°C for the duration of the hot soak rest.
To accommodate the volume changes due to enclosure temperature changes, either a
variable-volume or fixed-volume enclosure may be used.
4.2.1. Variable-volume Enclosure
The variable-volume enclosure expands and contracts in response to the temperature
change of the air mass in the enclosure. Two potential means of accommodating the
internal volume changes are movable panel(s), or a bellows design, in which an
impermeable bag or bags inside the enclosure expand(s) and contracts(s) in response to
internal pressure changes by exchanging air from outside the enclosure. Any design for
volume accommodation shall maintain the integrity of the enclosure as specified in
Paragraph 4.2.3. of this Annex over the specified temperature range.
Any method of volume accommodation shall limit the differential between the enclosure
internal pressure and the barometric pressure to a maximum value of ±0.5kPa.
The enclosure shall be capable of latching to a fixed volume. A variable volume enclosure
shall be capable of accommodating a +7% change from its "nominal volume" (see
Paragraph 4.2.3.1.1. of this Annex,), taking into account temperature and barometric
pressure variation during testing.
4.2.2. Fixed-volume Enclosure
The fixed-volume enclosure shall be constructed with rigid panels that maintain a fixed
enclosure volume and meet the requirements below.
4.2.2.1. The enclosure shall be equipped with an outlet flow stream that withdraws air at a low,
constant rate from the enclosure throughout the test. An inlet flow stream may provide
make-up air to balance the outgoing flow with incoming ambient air. Inlet air shall be filtered
with activated carbon to provide a relatively constant hydrocarbon level. Any method of
volume accommodation shall maintain the differential between the enclosure internal
pressure and the barometric pressure between 0 and -0.5kPa.

4.2.3.2.6. The chamber is then sealed and the background hydrocarbon concentration, temperature
and barometric pressure are measured. These are the initial readings C , P , T used in the
enclosure background calculation.
4.2.3.2.7. The enclosure is allowed to stand undisturbed with the mixing fan on for a period of 4h.
4.2.3.2.8. At the end of this time the same analyser is used to measure the hydrocarbon concentration
in the chamber. The temperature and the barometric pressure are also measured. These
are the final readings C , P , T .
4.2.3.2.9. The change in mass of hydrocarbons in the enclosure shall be calculated over the time of
the test in accordance with Paragraph 4.2.3.4. of this Annex and shall not exceed 0.05g.
4.2.3.3. Calibration and Hydrocarbon Retention Test of the Chamber
The calibration and hydrocarbon retention test in the chamber provides a check on the
calculated volume in Paragraph 4.2.3.1. of this Annex and also measures any leak rate. The
enclosure leak rate shall be determined at the enclosure's introduction to service, after any
operations in the enclosure which may affect the integrity of the enclosure, and at least
monthly thereafter. If six consecutive monthly retention checks are successfully completed
without corrective action, the enclosure leak rate may be determined quarterly thereafter as
long as no corrective action is required.
4.2.3.3.1. The enclosure shall be purged until a stable hydrocarbon concentration is reached. The
mixing fan is turned on, if not already switched on. The hydrocarbon analyser is zeroed,
calibrated if required, and spanned.
4.2.3.3.2. On variable-volume enclosures, the enclosure shall be latched to the nominal volume
position. On fixed-volume enclosures the outlet and inlet flow streams shall be closed.
4.2.3.3.3. The ambient temperature control system is then turned on (if not already on) and adjusted
for an initial temperature of 35°C, or at the choice of the manufacturer 36°C.
4.2.3.3.4. When the enclosure stabilises at 35°C ± 2°C, or at the choice of the manufacturer
36°C ± 2°C, the enclosure is sealed and the background concentration, temperature and
barometric pressure measured. These are the initial readings C , P , T used in the
enclosure calibration.
4.2.3.3.5. A quantity of approximately 4g of propane is injected into the enclosure. The mass of
propane shall be measured to an accuracy and precision of ±2% of the measured value.
4.2.3.3.6. The contents of the chamber shall be allowed to mix for 5min and then the hydrocarbon
concentration, temperature and barometric pressure are measured. These are the readings
C , P , T for the calibration of the enclosure as well as the initial readings C , P , T for the
retention check.
4.2.3.3.7. Based on the readings taken according to Paragraphs 4.2.3.3.4. and 4.2.3.3.6. of this Annex
and the formula in Paragraph 4.2.3.4. of this Annex, the mass of propane in the enclosure is
calculated. This shall be within ±2% of the mass of propane measured in
Paragraph 4.2.3.3.5. of this Annex.

4.3.1.3. The repeatability of the analyser expressed as one standard deviation shall be better than
±1% of full scale deflection at zero and at 80 ± 20% of full scale on all ranges used.
4.3.1.4. The operational ranges of the analyser shall be chosen to give best resolution over the
measurement, calibration and leak checking procedures.
4.3.2. Hydrocarbon Analyser Data Recording System
4.3.2.1. The hydrocarbon analyser shall be fitted with a device to record electrical signal output
either by strip chart recorder or other data processing system at a frequency of at least once
per minute. The recording system shall have operating characteristics at least equivalent to
the signal being recorded and shall provide a permanent record of results. The record shall
show a positive indication of the beginning and end of the hot soak or diurnal emission test
(including beginning and end of sampling periods along with the time elapsed between start
and completion of each test).
4.3.3. Checking of FID Hydrocarbon Analyser
4.3.3.1. Detector Response Optimisation
The FID shall be adjusted as specified by the instrument manufacturer. Propane in air
should be used to optimise the response on the most common operating range.
4.3.3.2. Calibration of the Hydrocarbon Analyser
The analyser should be calibrated using propane in air and purified synthetic air. See
Paragraph 6.2. of Annex 5 to UN GTR 15.
Each of the normally used operating ranges are calibrated in accordance with
Paragraphs 4.3.3.2.1. to 4.3.3.2.4. of this Annex.
4.3.3.2.1. Establish the calibration curve by at least five calibration points spaced as evenly as
possible over the operating range. The nominal concentration of the calibration gas with the
highest concentrations to be at least 80% of the full scale.
4.3.3.2.2. Calculate the calibration curve by the method of least squares. If the resulting polynomial
degree is greater than 3, then the number of calibration points shall be at least the number
of the polynomial degree plus 2.
4.3.3.2.3. The calibration curve shall not differ by more than 2% from the nominal value of each
calibration gas.

4.5. Pressure Recording System
The pressure recording system shall meet the requirements of Paragraphs 4.5.1. to 4.5.3 of
this Annex.
4.5.1. The difference Δp between barometric pressure within the test area and the enclosure
internal pressure shall, throughout the evaporative emission measurements, be recorded or
entered into a data processing system at a frequency of at least once per minute.
4.5.2. The accuracy of the pressure recording system shall be within ±0.3kPa and the pressure
shall be capable of being resolved to ±0.025kPa.
4.5.3. The recording or data processing system shall be capable of resolving time to ±15s.
4.6. Fans
The fans shall meet the requirements of Paragraphs 4.6.1. and 4.6.2. of this Annex.
4.6.1. By the use of one or more fans or blowers with the Sealed Housing Evaporative
Determination (SHED) door(s) open, it shall be possible to reduce the hydrocarbons
concentration in the chamber to the ambient hydrocarbon level.
4.6.2. The chamber shall have one or more fans or blowers of like capacity 0.1 to 0.5m /s with
which to thoroughly mix the atmosphere in the enclosure. It shall be possible to attain an
even temperature and hydrocarbon concentration in the chamber during measurements.
The vehicle in the enclosure shall not be subjected to a direct stream of air from the fans or
blowers.
4.7. Calibration Gases
The gases shall meet the requirements of Paragraph 4.8. of Annex 7 to the 07 series of
amendments to UN Regulation No. 83.
4.7.1. The following pure gases shall be available for calibration and operation:
Purified synthetic air: (purity < 1ppm C equivalent,
≤1ppm CO, ≤ 400ppm CO , ≤ 0.1ppm NO);
Oxygen content between 18 and 21% by volume.
Hydrocarbon analyser fuel gas: (40 ± 2% hydrogen, and balance helium with less than
1ppm C equivalent hydrocarbon, less than 400ppm CO ),
Propane (C H ):
Butane (C H ):
Nitrogen (N ):
99.5% minimum purity.
98% minimum purity.
98% minimum purity.

Figure A1/1
Carbon Canister Bench Ageing Procedure
5.1.1. Ageing through Exposure to Temperature Cycling
The carbon canister shall be cycled between temperatures from -15°C to 60°C in a
dedicated temperature enclosure with 30min of stabilisation at -15°C and 60°C. Each cycle
shall last 210min (see Figure A1/2).
The temperature gradient shall be as close as possible to 1°C/min. No forced air flow should
pass through the carbon canister.
The cycle shall be repeated 50 times consecutively. In total, this procedure lasts 175h.
Figure A1/2
Temperature Conditioning Cycle

5.1.3.3. The manufacturer shall provide the responsible authority a test report including at least the
following elements:
(a)
(b)
(c)
Type of activated carbon;
Loading rate;
Fuel specifications.
5.2. Determination of the PF of the Fuel Tank System (see Figure A1/3)
Figure A1/3
Determination of the PF

5.2.8. As an alternative to Paragraphs 5.2.1. to 5.2.7. inclusive of this Annex, a manufacturer using
multilayer tanks or metal tanks may choose to use an Assigned Permeability Factor (APF)
instead of performing the complete measurement procedure mentioned above:
APF multilayer/metal tank = 120mg/24h
Where the manufacturer chooses to use an APF, the manufacturer shall provide the
responsible authority with a declaration in which the type of tank is clearly specified as well
as a declaration of the type of materials used.
6. TEST PROCEDURE FOR THE MEASUREMENT OF HOT SOAK AND DIURNAL LOSSES
6.1. Vehicle Preparation
The vehicle shall be prepared in accordance with Paragraphs 6.1.1. and 6.1.2. of this
Annex. At the request of the manufacturer and with approval of the responsible authority,
non-fuel background emission sources (e.g. paint, adhesives, plastics, fuel/vapour lines,
tyres, and other rubber or polymer components) may be reduced to typical vehicle
background levels before testing (e.g. baking of tyres at temperatures of 50°C or higher for
appropriate periods, baking of the vehicle, draining washer fluid).
For a sealed fuel tank system, the vehicle carbon canisters shall be installed so that access
to carbon canisters and connection/disconnection of carbon canisters can be done easily.
6.1.1. The vehicle shall be mechanically prepared before the test as follows:
(a)
(b)
(c)
(d)
(e)
The exhaust system of the vehicle shall not exhibit any leaks;
The vehicle may be steam-cleaned before the test;
In the case of use of the gasoline canister load option (Paragraph 6.5.5.3. of this
Annex) the fuel tank of the vehicle shall be equipped with a temperature sensor to
enable the temperature to be measured at the mid-point of the fuel in the fuel tank
when filled to 40% of its capacity;
Additional fittings, adapters of devices may be fitted to the fuel system in order to
allow a complete draining of the fuel tank. For this purpose it is not necessary to
modify the shell of the tank;
The manufacturer may propose a test method in order to take into account the loss of
hydrocarbons by evaporation coming only from the fuel system of the vehicle.
6.1.2. The vehicle is taken into the test area where the ambient temperature is between 20 and
30°C.
6.2. Mode Selections and Gear Shift Prescriptions
6.2.1. For vehicles with manual shift transmissions, the gear shift prescriptions specified in
Annex 2 to UN GTR No. 15 shall apply.
6.2.2. In the case of conventional Internal Combustion Engine (ICE) vehicles, the mode shall be
selected according to Annex 6 to UN GTR No. 15.

Figure A1/4
Test Procedure Flow Charts

6.5.5.2. Carbon Canister Loading
The carbon canister aged according to the sequence described in Paragraph 5.1. to
5.1.3.1.3. inclusive of this Annex shall be loaded to 2g breakthrough according to the
procedure described in Paragraph 6.5.5.2.1. of this Annex.
One of the methods specified in Paragraphs 6.5.5.3. and 6.5.5.4. of this Annex shall be
used to precondition the evaporative canister. For vehicles with multiple canisters, each
canister shall be preconditioned separately.
6.5.5.2.1. Canister emissions are measured to determine breakthrough.
Breakthrough is here defined as the point at which the cumulative quantity of hydrocarbons
emitted is equal to 2g.
6.5.5.2.2. Breakthrough may be verified using the evaporative emission enclosure as described in
Paragraphs 6.5.5.3. and 6.5.5.4. of this Annex. Alternatively, breakthrough may be
determined using an auxiliary evaporative canister connected downstream of the vehicle's
canister. The auxiliary canister shall be well purged with dry air prior to loading.
6.5.5.2.3. The measuring chamber shall be purged for several minutes immediately before the test
until a stable background is obtained. The chamber air mixing fan(s) shall be switched on at
this time.
The hydrocarbon analyser shall be zeroed and spanned immediately before the test.
6.5.5.3. Canister Loading with Repeated Heat Builds to Breakthrough
6.5.5.3.1. The fuel tank(s) of the vehicle(s) is (are) emptied using the fuel tank drain(s). This shall be
done so as not to abnormally purge or abnormally load the evaporative control devices fitted
to the vehicle. Removal of the fuel cap is normally sufficient to achieve this.
6.5.5.3.2. The fuel tank(s) is (are) refilled with test fuel at a temperature of between 10 to 14°C to
40 ± 2% of the tank's normal volumetric capacity. The fuel cap(s) of the vehicle shall be
fitted at this point.
6.5.5.3.3. Within 1h of being refuelled the vehicle shall be placed, with the engine shut off, in the
evaporative emission enclosure. The fuel tank temperature sensor is connected to the
temperature recording system. A heat source shall be properly positioned with respect to
the fuel tank(s) and connected to the temperature controller. The heat source is specified in
Paragraph 4.9. of this Annex. In the case of vehicles fitted with more than one fuel tank, all
the tanks shall be heated in the same way as described below. The temperatures of the
tanks shall be identical to within ±1.5°C.
6.5.5.3.4. The fuel may be artificially heated to the starting diurnal temperature of 20°C ± 1°C.
6.5.5.3.5. When the fuel temperature reaches at least 19°C, the following steps shall be taken
immediately: the purge blower shall be turned off; enclosure doors closed and sealed; and
measurement initiated of the hydrocarbon level in the enclosure.

6.5.7. Hot Soak Evaporative Emissions Test
Within 7min after the dynamometer test and within 2min of the engine being switched off,
the hot soak evaporative emissions test shall be performed in accordance with
Paragraphs 6.5.7.1. to 6.5.7.8. of this Annex. The hot soak losses shall be calculated
according to Paragraph 7.1. of this Annex and recorded as M .
6.5.7.1. Before the completion of the test run the measuring chamber shall be purged for several
minutes until a stable hydrocarbon background is obtained. The enclosure mixing fan(s)
shall also be turned on at this time.
6.5.7.2. The hydrocarbon analyser shall be zeroed and spanned immediately prior to the test.
6.5.7.3. At the end of the driving cycle the engine bonnet shall be completely closed and all
connections between the vehicle and the test stand disconnected. The vehicle is then driven
to the measuring chamber with a minimum use of the accelerator pedal. The engine shall be
turned off before any part of the vehicle enters the measuring chamber. The time at which
the engine is switched off is recorded on the evaporative emission measurement data
recording system and temperature recording begins. The vehicle's windows and luggage
compartments shall be opened at this stage, if not already opened.
6.5.7.4. The vehicle shall be pushed or otherwise moved into the measuring chamber with the
engine switched off.
6.5.7.5. The enclosure doors are closed and sealed gas-tight within 2min of the engine being
switched off and within 7min of the end of the conditioning drive.
6.5.7.6. The start of a 60 ± 0.5min hot soak period begins when the chamber is sealed. The
hydrocarbon concentration, temperature and barometric pressure are measured to give the
initial readings C , P and T for the hot soak test. These figures are used in the
evaporative emission calculation, Paragraph 6. The ambient temperature T of the enclosure
shall not be less than 23°C and no more than 31°C during the 60min hot soak period.
6.5.7.7. The hydrocarbon analyser shall be zeroed and spanned immediately before the end of the
60 ± 0.5min test period.
6.5.7.8. At the end of the 60 ± 0.5min test period, the hydrocarbon concentration in the chamber
shall be measured. The temperature and the barometric pressure are also measured. These
are the final readings C , P and T for the hot soak test used for the calculation in
Paragraph 6. of this Annex.
6.5.8. Soak
After the hot soak evaporative emissions test, the test vehicle shall be soaked for not less
than 6h and not more than 36h between the end of the hot soak test and the start of the
diurnal emission test. For at least the last 6h of this period the vehicle shall be soaked at
20°C ± 2°C.

Table A1/1 (continued)
Diurnal ambient temperature profile for the calibration of the
enclosure and the diurnal emission test
Alternative diurnal ambient temperature
profile for the calibration of the enclosure
Calibration
Time (hours)
Test
Temperature (°C ) Time (hours) Temperature (°C )
9
20
23.0
20
31.9
10
21
22.0
21
33.9
11
22
20.8
22
35.1
12
23
20.2
23
3.4
24
35.6
6.5.9.2. The enclosure shall be purged for several minutes immediately before the test until a stable
background is obtained. The chamber mixing fan(s) shall also be switched on at this time.
6.5.9.3. The test vehicle, with the powertrain shut off and the test vehicle windows and luggage
compartment(s) opened, shall be moved into the measuring chamber. The mixing fan(s)
shall be adjusted in such a way as to maintain a minimum air circulation speed of 8km/h
under the fuel tank of the test vehicle.
6.5.9.4. The hydrocarbon analyser shall be zeroed and spanned immediately before the test.
6.5.9.5. The enclosure doors shall be closed and sealed gas-tight.
6.5.9.6. Within 10min of closing and sealing the doors, the hydrocarbon concentration, temperature
and barometric pressure shall be measured to give initial readings of hydrocarbon
concentration in the enclosure (C ), barometric pressure (P ) and ambient chamber
temperature (T ) for the diurnal testing. T = 0 starts at this time.
6.5.9.7. The hydrocarbon analyser shall be zeroed and spanned immediately before the end of each
emission sampling period.
6.5.9.8. The end of the first and second emission sampling period shall occur at 24h ± 6min and
48h ± 6min, respectively, after the beginning of the initial sampling, as specified in
Paragraph 6.5.9.6. of this Annex. The elapsed time shall be recorded.
At the end of each emission sampling period, the hydrocarbon concentration, temperature
and barometric pressure shall be measured and used to calculate the diurnal test results
using the equation in Paragraph 7.1. of this Annex. The result obtained from the first 24h
shall be recorded as M . The result obtained from the second 24h shall be recorded as
M .

6.6.1.5.1. Determination of Maximum Purge Volume
The maximum purge amount Vol shall be determined by the following equation. In the
case of OVC-HEVs, the vehicle shall be operated in charge-sustaining operating condition.
This determination can also be done at a separate test or during the preconditioning drive.
Where:
Vol
is the cumulative purge volume rounded to the nearest 0.1l measured using a
suitable device (e.g. flowmeter connected to the vent of the carbon canister or
equivalent) over the cold start preconditioning drive described in the
Paragraph 6.5.3. of this Annex, l;
Vol is the manufacturer's nominal fuel tank capacity, l;
FCP
is the fuel consumption over the single purge cycle described in
Paragraph 6.5.3. of this Annex which may be measured in either warm or cold
start condition, 1/100km. For OVC-HEVs and NOVC-HEVs, fuel consumption
shall be calculated according to Paragraph 4.2.1. of Annex 8 of UN GTR 15;
Dist
is the theoretical distance to the nearest 0.1km of a single purge cycle
described in Paragraph 6.5.3. of this Annex, km.
6.6.1.6. Preparation of Carbon Canister Depressurisation Puff Loss Loading
After completing carbon canister loading and purging, the test vehicle shall be moved into
an enclosure, either a SHED or an appropriate climatic chamber. It shall be demonstrated
that the system is leak-free and the pressurisation is performed in a normal way during the
test or by a separate test (e.g. by means of pressure sensor on the vehicle). The test vehicle
shall be subsequently exposed to the first 11h of the ambient temperature profile specified
for the diurnal emission test in Table A1/1 with a maximum deviation of ±2°C at any time.
The average temperature deviation from the profile, calculated using the absolute value of
each measured deviation, shall not exceed ±1°C. The ambient temperature shall be
measured and recorded at least every 10min.
6.6.1.7. Carbon Canister Puff Loss Loading
6.6.1.7.1. Fuel Tank Depressurisation before Refuelling
The manufacturer shall ensure that the refuelling operation cannot be initiated before the
sealed fuel tank system is fully depressurised to a pressure less than 2.5kPa above ambient
pressure in normal vehicle operation and use. At the request of the responsible authority,
the manufacturer shall provide detailed information or demonstrate proof of operation (e.g.
by means of pressure sensor on the vehicle). Any other technical solution may be allowed
provided that a safe refuelling operation is ensured and that no excessive emissions are
released to the atmosphere before the refuelling device is connected to the vehicle.

6.6.1.9. Soak
After completing puff loss loading the vehicle carbon canister shall be replaced with a
dummy carbon canister (of the same specification as the original but not necessarily aged),
the vehicle shall then be soaked at 23 ± 2°C for 6 to 36h to stabilise the vehicle
temperature.
6.6.1.9.1. REESS Charge
For OVC-HEVs, the REESS shall be fully charged in accordance with the charging
requirements described in Paragraph 2.2.3. of Appendix 4 to Annex 8 to UN GTR No. 15
during the soaking described in Paragraph 6.6.1.9. of this Annex.
6.6.1.10. Fuel Drain and Refill
6.6.1.11. Soak
The fuel tank of the vehicle shall be drained and filled up to 40 ± 2% of the tank's nominal
capacity with reference fuel at a temperature of 18°C ± 2°C.
The vehicle shall be subsequently parked for a minimum of 6h to a maximum of 36h in the
soak area at 20°C ± 2°C to stabilise the fuel temperature.
6.6.1.12. Fuel Tank Depressurisation
The tank pressure shall be subsequently released so as not to abnormally raise the inside
pressure of the fuel tank. This may be done by opening the fuel cap of the vehicle.
Regardless of the method of depressurisation, the vehicle shall be returned to its original
condition within 1min. After this action, the vehicle carbon canister shall be connected again.
6.6.1.13. The procedures in Paragraphs 6.5.6. to 6.5.9.8. inclusive of this Annex shall be followed.
6.6.2. In the Case that the Fuel Tank Relief Pressure is Lower than 30kPa
The test shall be performed as described in Paragraphs 6.6.1.1. to 6.6.1.13. inclusive of this
Annex. However, in this case, the ambient temperature described in Paragraph 6.5.9.1. of
this Annex shall be replaced by the profile specified in Table A1/2 of this Annex for the
diurnal emission test.

6.7. Stand-alone Test Procedure for Sealed Fuel Tank Systems
6.7.1. Measurement of Depressurisation Puff Loss Loading Mass
6.7.1.1. The procedures in Paragraphs 6.6.1.1. to 6.6.1.7.2. inclusive of this Annex shall be
performed. The depressurisation puff loss loading mass is defined as the difference in
weight of the vehicle carbon canister before Paragraph 6.6.1.6. of this Annex is applied and
after Paragraph 6.6.1.7.2. of this Annex is applied.
6.7.1.2. The depressurisation puff loss overflow from the vehicle carbon canister shall be measured
according to Paragraphs 6.6.1.8.1. and 6.6.1.8.2. inclusive of this Annex and fulfil the
requirements of Paragraph 6.6.1.8.3. in this Annex.
6.7.2. Hot Soak and Diurnal Breathing Evaporative Emissions Test
6.7.2.1. In the Case that the Fuel Tank Relief Pressure is Greater than or Equal to 30kPa
6.7.2.1.1. The test shall be performed as described in Paragraphs 6.5.1. to 6.5.3. and 6.6.1.9. to
6.6.1.9.1. inclusive of this Annex.
6.7.2.1.2. The carbon canister shall be aged according to the sequence described in Paragraph 5.1. to
5.1.3.1.3. inclusive of this Annex and shall be loaded and purged according to
Paragraph 6.6.1.5. of this Annex.
6.7.2.1.3. The aged carbon canister shall subsequently be loaded according to the procedure
described in Paragraphs 6.5.5.4. However, instead of loading to breakthrough as described
in Paragraph 6.5.5.4.4. the total loading mass shall be determined according to
Paragraph 6.7.1.1. of this Annex. At the request of the manufacturer, the reference fuel may
alternatively be used instead of butane. The carbon canister shall be disconnected.
6.7.2.1.4. The procedures in Paragraphs 6.6.1.10. to 6.6.1.13. inclusive of this Annex shall be
followed.
6.7.2.2. In the Case that the Fuel Tank Relief Pressure is Lower than 30kPa
The test shall be performed as described in Paragraphs 6.7.2.1.1. to 6.7.2.1.4. inclusive of
this Annex. However, in this case, the ambient temperature described in 6.5.9.1. of this
Annex shall be modified in accordance with the profile specified in Table A1/1 of this Annex
for the diurnal emission test.

7.1.1. As an alternative to the equation in Paragraph 7.1. of this Annex, for variable volume
enclosures the following equation may be used at the choice of the manufacturer:
Where:
M is the mass of hydrocarbons, grams;
C is the measured hydrocarbon concentration in the enclosure, ppm volume in C
equivalent;
V
is the net enclosure volume corrected for the volume of the vehicle with the
windows and the luggage compartment open, m . If the volume of the vehicle is
not known, a volume of 1.42m shall be subtracted;
T is the initial ambient chamber temperature, K;
P
H/C
H/C
H/C
H/C
k
i
f
is the initial barometric pressure, kPa;
is the hydrogen to carbon ratio;
is taken to be 2.33 for puff loss overflow measurement in SHED and diurnal test
losses;
is taken to be 2.20 for hot soak losses;
is taken to be 2.67 for calibration;
is 1.2 × 10 × (12 + H/C), in (g × K/(m × kPa));
is the initial reading;
is the final reading.
7.2. The result of (M + M + M + (2 × PF)) shall be below the limit defined in
Paragraph 6.1.(a) of this UN GTR.
7.3. At the option of the Contracting Party, the following may be used:
The result of (M + M + PF) shall be below the limit defined in Paragraph 6.1.(b) of this
UN GTR. The M shall be either M or M , whichever generates the higher emission.

ANNEX 2
REFERENCE FUELS
1. As there are regional differences in the market specifications of fuels, regionally different
reference fuels need to be recognised. Contracting Parties may select their reference fuels
either according to Annex 3 to UN GTR No. 15. or according to Paragraph 2. of this Annex.
2. SPECIFICATION OF REFERENCE FUEL FOR TESTING FOR MUTUAL RECOGNITION
The reference fuel listed in Table A2/1 is designed to be used as the reference fuel for
mutual recognition under the rules of the 1998 Agreement.
3. SPECIFICATION OF REFERENCE FUEL FOR REGIONAL TESTING
The reference fuel listed in Annex 3 to UN GTR No. 15. may be used for this purpose.

ANNEX 3 – (OPTIONAL)
COP PROCEDURE FOR TYPE 4 TEST
1. INTRODUCTION
Every vehicle produced under a type approval according to this Regulation shall conform for
the Type 4 test, in accordance with Table A3/1 to the vehicle type approved.
Table A3/1
Type 4 Applicable Type 4 CoP Requirements for the Different Vehicle Types
Vehicle type
Evaporative emissions
ICE
NOVC-HEV
OVC-HEV
PEV
NOVC-FCHV
OVC-FCHV
YES
YES
YES
Not Applicable
Not Applicable
Not Applicable
2. COP FAMILY
For the purposes of the manufacturer's conformity of production check on the Type 4 test, the
family means the conformity of production (CoP) family, which shall be identical to the
evaporative emissions family, as described in Paragraph 5.5. of this UN GTR.
3. TEST FREQUENCY
Once per year a vehicle shall be randomly taken from the CoP family described in Paragraph 2
to this Annex and subjected to the three tests described in Paragraph 7 of this Annex.
4. TEST FUEL
All these tests shall be conducted with reference fuel in accordance with the specifications in
Annex 2.

7. CONFORMITY OF PRODUCTION
7.1. In case of vehicles with a sealed fuel tank system, at the request of the manufacturer and in
agreement with the responsible authority, alternative procedures to Paragraphs 7.2. to 7.4 can
be applied.
When the manufacturer chooses to use any alternative procedure, all the details of the
conformity test procedure shall be recorded in the type approval documentation.
7.2. Test for Leakage
7.2.1. Vents to the atmosphere from the emission control system shall be isolated.
7.2.2. A pressure of 3.70kPa ± 0.10kPa shall be applied to the fuel system. At the request of
manufacturer and with approval of the responsible authority, an alternative pressure can also
be applied, taking into account the pressure range in use of the fuel system.
7.2.3. The pressure shall be allowed to stabilise prior to isolating the fuel system from the pressure
source.
7.2.4. Following isolation of the fuel system, the pressure shall not drop by more than 0.50kPa in
5min.
7.2.5. At the request of the manufacturer and in agreement with the responsible authority the function
for leakage can be demonstrated by an equivalent alternative procedure.
7.3. Test for Venting
7.3.1. Vents to the atmosphere from the emission control shall be isolated.
7.3.2. A pressure of 3.70kPa ± 0.10kPa shall be applied to the fuel system. At the request of
manufacturer and with approval of the responsible authority, an alternative pressure can also
be applied, taking into account the pressure range in use of the fuel system.
7.3.3. The pressure shall be allowed to stabilise prior to isolating the fuel system from the pressure
source.
7.3.4. The venting outlets from the emission control systems to the atmosphere shall be reinstated to
the production condition.
7.3.5. The pressure of the fuel system shall drop to below a pressure less than 2.5kPa above ambient
pressure within 1min.
7.3.6. At the request of the manufacturer and in agreement with the responsible authority the
functional capacity for venting can be demonstrated, when applicable, by an equivalent
alternative procedure.

Evaporative Emission Test Procedure for the Worldwide Harmonized Light Vehicle Test Procedure (WLTP EVAP).