Reference number  
DRS 407-2: 2019  
© RSB 2019  
 
 
 RWANDA 
STANDARD  DRS 
407-2 
 
First e dition  
2019 -mm-dd 
 
Emission limits — Specification  
Part 2: 
Non-road mobile machinery  
  DRS 407-2: 2019  
©RSB 2019  - All rights reserved                  ii 
 In order to match with technological development and to keep continuous progress in industries, 
standards are subject to periodic review. Users shall ascertain that they are in possession of the latest 
edition  
 
 
 
 
 
 
 
 
© RSB 2019  
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized 
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without 
prior written permission from R SB. 
Requests for permission to reprodu ce this document should be addressed to : 
Rwanda Standards  Board  
P.O Box 7099 Kigali -Rwanda  
KK 15 Rd, 49  
Tel. +250 788303492  
Toll Free: 3250  
E-mail: info@rsb.gov.rw  
Website: www.rsb.gov.rw   
ePortal: www.portal.rsb.gov.rw     DRS 407-2: 2019  
iii                ©RSB 2019  - All rights reserved  
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ...................  iv 
1 Scope  ................................ ................................ ................................ ................................ .............  1 
2 Normative references  ................................ ................................ ................................ ...................  1 
3 Terms and definitions  ................................ ................................ ................................ ..................  1 
4 Requirements  ................................ ................................ ................................ ................................  4 
4.1 General requirement  ................................ ................................ ................................ ....................  4 
4.2 Specific requirements  ................................ ................................ ................................ ..................  4 
5 Test methods  ................................ ................................ ................................ ................................  5 
Annex  A (informative)  Classes of spark -ignition (SI) engines ................................ .............................  6 
Annex  B (normative)  Test methods  ................................ ................................ ................................ ........  7 
B.1 Testing of non -road mobile machinery with compression -ignition (CI) engines  ..................  7 
B.2 Testing of non -road mobile machinery with spark -igniti on (SI) engines  ...............................  7 
 DRS 407-2: 2019  
©RSB 2019  - All rights reserved                  iv 
 Foreword   
Rwanda Standard s are prepared  by Technical Committees and approved by R wanda Standards Board (RSB) 
Board  of Directors in  accordance with the procedures of RSB, in compliance with Annex 3 of the WTO/TBT 
agreement on the preparation, adoption and application of standards.  
The main task of technical committees is to prepare national standards.  Final Draft Rwanda S tandards adop ted 
by Technical committ ees are ratified  by me mbers of RSB Board of Director s for publication and gazettment as 
Rwanda Standards.  
DRS 407-2 was prepared by Joint Technical Committee RSB/TC 023, Road vehicle s and RSB/TC 041, 
Environmental protection .. 
DRS 407 consists of the following parts, under the general title Emission limits  — Specification : 
 Part 1: Road vehicles  
 Part 2: Non-road mobile machinery  
Part 3: Thermal power plants  
Committee membership  
The following organizations were represented on the Joint Technical Committee on Road vehicles (RSB/TC 23) 
and Environmental protection (RSB/TC 41)  in the preparation of this standard.  
Akagera Motors  
Energy Development Corporation Ltd (EDCL)  
Integrated Polytechnic Regional College (IPRC) Kigali  
Metropole Mo tors 
Ministry of Environment (MoE)  
Ministry of Infrastructure (MININFRA)  
Ministry of Trade and Industry (MINICOM)  
PurePro® Ltd  
Real Contractors Ltd  
Rwanda Environment Management Company (RWEMACO)    DRS 407-2: 2019  
v                ©RSB 2019  - All rights reserved  
 Rwanda Garages Association (RGA)  
Rwanda National Police (RNP)  
Rwanda Transport Development Agency (RTDA)  
Rwanda Utility Regulatory Agency (RURA)  
SAR Motor  
Standards for Sustainability (SfS)  
Sulfo Industries Rwanda  
TUMECO Garage  
University of Rwanda — College of Science and Technology (UR — CST)  
Rwanda Standards  Board (RSB) – Secretariat  
  DRS 407-2: 2019  
©RSB 2019  - All rights reserved                  vi 
 Introduction  
This Draft Rwanda Standard was preceded by a Rapid Situational Assessment Report that established that 
there are currently no Rwanda standards or emission limits in place for non -road mobile machinery (NRMM) 
including construction and agricultural machinery, engine -run hand -held equipment and generators. The report 
further established that, whereas in a few developed countries e.g. UK have in -use emission limits for some of 
the NRMM, the majority of countries only have type approval/certification emission standards for new ( off-
factory) equipment. This is because of the small numbers of these kinds of equipment and their sparse 
distribution; hence their overall impact on air quality is generally very low and localized, and overall air pollution 
reductions from their regulatio n is also very small.  
Additionally, testing infrastructure for in -use NRMM, engine -run hand -held equipment and generators does not 
exist in most countries, just like in Rwanda. The report, therefore, recommended Rwanda to develop standards 
for new (off -factory) equipment that are placed in the Rwandan market, mainly through importation, noting that 
Rwanda does not currently manufacture any of these equipment.  Such a standard as proposed herein can be 
easily implemented/enforced, for example, through a reg ulation requiring that all imported NRMM be 
accompanied by a type -approval certificate/sticker issued by an approval authority in the country of 
manufacture.  
 DRS 407-2: 2019  
1                ©RSB 2019  - All rights reserved  
 Emission limits — Specification — Part 2: Non -road mobile machinery  
1 Scope  
This Draft Rwanda Standard specifies  emission limits for all categories of internal combustion engines installed 
in non-road mobile machinery used in Rwanda.  
2 Normative references  
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document. For dated references, only the edition cited applie s. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
ISO 8178 -4, Reciprocating internal combustion engines — Exhaust emission measurement  — Part 4: Steady -
state and transient test cycles for different  engine applications  
3 Terms and definitions  
For the purposes of this standard, the follow ing terms and definitions apply.  
3.1  
non-road mobile machinery  
mobile machine, transportable industrial equipment or vehicle with or without body work, not intended f or 
passenger or goods transport on the road, in which an internal combustion engine as specified in Annex A 
(Table A1) is installed  
3.2 
type-approval  
procedure whereby an approval authority in the country of manufacture certifies that an internal combustion 
engine type satisfies the relevant technical requirements with regard to the emission limits specified in this 
standard or other equivalent/greater standard  
3.3 
approval authority  
competent authority in the country of manufacture responsible for  all aspects of type -approval of an engine and 
for verifying the manufacturer's conformity of emission requirements   
©RSB 2019  - All rights reserved                  2 
 3.4 
hand -held engine  
engine that meets at least one of the following requirements:  
a) engine must be used in a piece of equipment that is carri ed by the operator throughout the performance of 
its intended functions;  
b) engine must be used in a piece of equipment that must operate multipositionally, such as upside down or 
sideways, to complete its intended function(s);  
c) engine must be used in a piece of equipment for which the combined engine and equipment dry weight is 
under 20 kg  and at least one of the following attributes is also present:  
1) operator must alternatively provide support or carry the equipment throughout the performance of 
its intended f unction(s);  
2) operator must provide support or attitudinal control for the equipment throughout the performance 
of its intended function(s);  or 
3) engine must be used in a generator or a pump.  
3.5 
non-hand -held engine  
engine that is used in a piece of equipment  that is not carried or supported by the operator during the 
performance of its intended functions  
3.6  
engine type  
category of engines which do not differ in such essential engine characteristics  
3.7 
engine family  
manufacturer's grouping of engines whic h, through their design, are expected to have similar exhaust emission 
characteristics and which comply with the requirements in Clause 4 of this standard  
3.8 
compression ignition (C.I.) engine  
internal combustion engine which works on the compression -ignition principle, i.e., an engine  in which  ignition  of 
the fuel, which is injected into the combustion chamber, is caused by the elevated temperature of the air in the 
cylinder due to the mechanical compression, and is generally a diesel engine  DRS 407-2: 2019  
3                ©RSB 2019  - All rights reserved  
 3.9 
spark ignition (SI) engine  
internal combustion engine which works on the spark -ignition principle, i.e., where the combustion process of 
the air -fuel mixture is ignited  by a spark  from a  spark  plug, and is generally a petrol engine  
3.10 
test cycle  
sequence of te st points, each with a defined speed and torque, to be followed by the engine under steady state  
3.11 
rated speed  
maximum full load speed allowed by the governor as specified by the manufacturer  
3.12 
per cent load  
fraction of the maximum available torque a t an engine speed  
3.13 
maximum torque speed  
engine speed at which the maximum torque is obtained from the engine, as specified by the manufacturer  
3.14 
intermediate speed  
engine speed which meets one of the following requirements:  
a) for engines which are des igned to operate over a speed range on a full load torque curve, the intermediate 
speed shall be the declared maximum torque speed if it occurs between 60 % and 75 % of rated speed ; 
b) if the declared maximum torque speed is less than 60 % of rated speed, the n the intermediate speed shall 
be 60 % of the rate d speed;  
c) if the declared maximum torque speed is greater than 75 % of the rated speed then the intermediate spe ed 
shall be 75 % of rated speed; or  
d) for engines to be tested on cycle G1, the intermediate spee d shall be 85 % of the maximum rated speed .   
©RSB 2019  - All rights reserved                  4 
 4 Requirements  
4.1 General requirement  
Any non -road mobile machinery , which is subject to this standard,  shall fall in one of the following two categories:  
Category 1: diesel -powered machinery  
Category 2: gasoline -powered machinery  
4.2 Specific requirements  
All non -road mobile machinery , which are subject to this standard , shall meet emission requirements set out in  
Table 1 & Table 2.  
Table 1 — Type approval/certification emission limits for new imported diesel -powered (compression 
ignition) engines for non -road mobile machinery  
Net engine power (p) (KW)  Limit valuesa in g/kWh  Test m ethod  
CO HC NOx PM ISO 8178 -4 CI-8 
mode/NRSC*  
p>56O  3.5 0.5 6.0 0.2 
130≤p≤560  3.5 1.0 6.0 0.2 
75≤p<130  5.0 1.0 6.0 0.3 
37≤p<75  5.0 1.3 7.0 0.4 
18≤p<37  5.5 1.5 8.0 0.8 
*Non -Road Steady Cycle  
Table 2 — Type approval/certification e mission limits for new imported gasoline -powered engines 
for non-road mobile machinery (spark ignition engines)  
Engine Category  Limit values in g/kWh  Test method  
Class  CO HC NOx HC +NOx  ISO 8178 -4 
Hand -held  engine  SH1 805 295 5.36 N/A1 
SH2 805 241 5.36 N/A 
SH3 603 161 5.36 N/A 
Non-hand -held engine  SN1 519 N/A N/A 50 
                                                      
1 N/A: Not Applicable  DRS 407-2: 2019  
5                ©RSB 2019  - All rights reserved  
 SN2 519 N/A N/A 40 
SN3 519 N/A N/A 16.1 
SN4 519 N/A N/A 13.4 
NOTE For more detailed information on SH and SN, refer to Annex A . 
5 Test methods  
Emissions testing for all non -road mobile machinery subject to this standard shall be carried out in accordance 
with the test methods outlined in Annex B . 
 
 
 
 
 
 
  
©RSB 2019  - All rights reserved                  6 
 Annex  A 
 
(informative)  
 
Classes of spark -ignition (SI) engines  
Spark -ignition (SI) engines are divide d into the following class es: 
Main class S: small engines with a net power <19 kW  
The main class S shall be divided into two categories based on engine displacement:  
H: engines for hand -held machinery  
N: engines for non -hand -held machinery  
Table A1 — Engines classification based on their displacement  
Category  Class  Displacement (d) (cubic cm)  
Hand -held Engines  SH1 d< 20  
SH2 20≤d<50  
SH3 d≥50  
Non-Hand held engines  SN1 d< 66  
SN2  66≤d<100  
SN3 100≤d<225  
SN4 d≥225  
 
 
 
 
 
 
 
 DRS 407-2: 2019  
7                ©RSB 2019  - All rights reserved  
 Annex  B 
(normative)  
 
Test methods  
B.1 Testing of non -road mobile machinery with compression -ignition (CI) engines  
All non -road mobile machinery operating with compression ignition engines shall be tested according to the test 
procedures and conditions described under ISO 8178 -4 CI-8 mo de/Non -Road Steady Cycle (NRSC) Test. This 
test cycle consists of a number of speed and torque (load) modes, which cover the typical operating range of 
diesel engines.  
B.2 Testing of non -road mobile machinery with spark -ignition (SI) engines  
Emissions from sma ll non -road mobile machinery with spark -ignition engines shall be measured over one of 
four steady -state engine dynamometer test cycles (ISO 8178 -4), depending on the type of machinery as follows:  
a) Cycle D : engines with constant speed and intermittent load.  Such machines include generating sets with 
intermittent load including generating sets on board ships and trains (not for propulsion), refrigerating units, 
welding sets; gas compressors;  
b) Cycle G1: non -hand -held intermediate speed applications. Typical exa mples include front or rear engines 
riding lawn mowers; golf carts; lawn sweepers; pedestrian -controlled rotary or cylinder lawn mowers; snow -
removal equipment; waste disposers;  
c) Cycle G2: non -hand -held rated speed applications. Example include portable gen erators, pumps, welders 
and air compressors; may also include lawn and garden equipment, which operate at engine rated speed ; 
and 
d) Cycle G3: hand -held applications such as blowers; chain saws; hedge trimmers; portable saw mills; rotary 
tillers; sprayers; st ring trimmers; vacuum equipment .  
©RSB 2019  - All rights reserved                  8 
 Bibliography  
[1] Directive 97/68/EC of the European Parliament and of the Council, on the approximation of the laws of 
the Member States relating to measures against the emission of gaseous and particulate pollutants from 
internal combustion engines to be installed in non -road mobile machinery  
[2] Directive 2002/88/EC of the European Parliament and of the Council amending Directive 97/68/EC, on 
the approximation of the laws of the Member States relating to measures against the emiss ion of 
gaseous and particulate pollutants from internal combustion engines to be installed in non -road mobile 
machinery  
[3] Directive 2004/26/EC of the European Parliament and of the Council amending Directive 97/68/EC on 
the approximation of the laws of the Member States relating to measures against the emission of 
gaseous and particulate pollutants from internal combustion engines to be installed in non -road mobile 
machinery  
 DRS 407-2: 2019  
ICS 13.040.50  
 
 
©RSB 2019  - All right s reserved