KENYA STANDARD       DKS 2868 : 2018  
                                                                                 ICS  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Occupational s afety and health — 
sewermen — code of practice   
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
© KEBS 201 8 First Edition , 2018 
 
 
  DKS 2868 : 2018  
 
                                                                          ii  © KEBS 2018 — All rights reserved  TECHNICAL COMMITTEE REPRES ENTATION  
 
The following  organizations were represented on the Technical Committee:  
 
Directorate of Occupational Safety and Health Services (DOSHS)  
Kenyatta National Hospital (KNH)  
Radiation Protection Board  
Kenya Medical Research Institute (KEMRI)  
Kenyatta University — Departmen t of Environmental Health  
National Environmental Management Authority (NEMA)  
Ministry of Health — Department of Public Health  
Consumer Information Network  
East Africa association for radiation protection  
Kenya Bureau of Standards — Secretariat  
 
 
 
 
REVISION  OF KENYA STANDARDS  
 
In order to keep abreast of progress in industry, Kenya Standards shall be regularly reviewed.  Suggestions 
for improvements to published standards, addressed to the Managing Director, Kenya Bureau of Standards, 
are welcome.  
 
 
 
 
 
 
 
© Kenya Bureau of Standards, 201 8 
 
Copyright. Users are reminded that by virtue of Section 25 of the Copyright Act, Cap. 130 of 2001  of the Laws of Kenya, copy right subsists 
in all Kenya Standards and except as provided under Section 25 of this Act, no Keny a Standard produced by Kenya Bureau of Standards 
may be reproduced, stored in a retrieval system in any form or transmitted by any means without prior permission in writing f rom the 
Managing Director.  
  KENYA STANDARD                                          DKS 2868 : 2018  
                                                                                     ICS  
© KEBS 2018 — All rights reserved    iii  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Occupational s afety and health — 
sewermen —code of practice  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
KENYA BUREAU OF STANDARDS (KEBS)  
 
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  DKS 2868 : 2018  
 
                                                                          iv  © KEBS 2018 — All rights reserved   
Foreword  
 
This Kenya Standard has been prepared by the Sub -Technical Committee on Occupational Health and Safety 
under the guidance of the Standards Projects Committee, and it is in accordance with the procedures of the 
Kenya Bureau of Standards.  
 
During the preparation of this standard, reference was made to the following documents:  
 
ISO 45001:2018 - Occupational health and safety management systems — Requirements with guidance for 
use 
 
 ISO 14123 -1:2015 - Safety of machinery — Reduction of risks to health resulting from hazardous substances 
emitted by machinery — Part 1: Principles and Specifications for machinery manufacturers   
 
Acknowledgement is hereby made for the assistance received from these sources . 
 
  
KENYA STANDARD        DKS 2868 : 2018  
 
 
© KEBS 2018 — All rights reserved    1  
 Occupational s afety and health — sewermen —code of practice   
 
 
1 Scope  and field of application  
 
1.1 Scope  
 
This Kenya Standard lays down guidelines for selection of sewermen and safe system of work in sewerage 
system . It also recommends requisite training of workers be considered where applicable. These safety and 
health guidelines  shall be adhered to during the work process when working in sewerage system.  
 
1.2 Application  
 
This standard shall apply to personnel engaged in operation and maintenance of sewerage systems  
includin g sewage pumping stations  and sewage treatment plants  
2 Normative references  
 
The following referenced documents are indispensable for the application of this Kenya Standard. For dated 
refere nces, only the edition cited applies. For undated references, the latest edition of the referenced 
document (including any amendments) applies.  
 
ISO 45001:2018 - Occupational health and safety management systems — Requirements with guidance for 
use 
 
ISO 14123 -1:2015 Safety of machinery — Reduction of risks to health resulting from hazardous substances 
emitted by machinery — Part 1: Principles and Specifications for machinery manufacturers  
 
 
3 Terms and definitions   
For the purposes of this document, the following terms and definitions shall apply  
 
3.1  
sewer  
a pipe or conduit which is the property of or is vested in the County Government  and which is used or intended 
to be used for the conveyance of sewage.  
 
3.2  
sewermen  
men and women personnel  engaged in operation and maintenance of sewerage systems , including sewage 
pumping stations  and sewage treatment plants  
 
3.3  
sewage  
waste water, soil water, industrial effluent other liquid waste, either separately or in combination but does not 
include stor m water.  
 
3.4  
sewerage system  
system for removal of sewage  usually from beyond  the cartilage of more than one site.   
 
3.5  
top men  
are trained rescuers   
                                                                          2  © KEBS 2018 — All rights reserved   
3.6  
permit to work  
a written  notice, which sets out the work to be done, the hazards  involved and the precautions to be taken 
before the work commences in order to secu re the safety and health of the employee  or employees  
 
3.7  
employee  
a person employed for wages or a salary and includes an ap prentice and indentured learner  
 
3.8  
employer  
any person, public body, firm, corporation or company who or which has entered into a contract of service to 
employ any individual and includes the agent, foreman, manager or factor of such person, public bod y, firm, 
corporation or company  
 
3.9  
regulatory  Authority  
Government agency  formed or mandated under the terms of a legislative act (statute) to ensure compliance 
with the provisions of the act, and in carrying out its purpose.  
 
3.10  
personal protective equipment (PPEs)  
include protective clothing and app liances  
 
3.11  
 hazardous gas  
include toxic, noxious, dangerous, and inflammables gases  
 
4. Selection of s ewermen  
 
The employer should select the prospective employees for the sewerage and sewerage disposal  functions, 
taking  into account the duties they will be expected to perform. Those duties may be divided into two 
categories:  
a) duties not requiring entry into confined spaces, and  
b) duties requiring entry into confined spaces.  
Requisite training of the selected workers shall where applicable be considered  
 
4.1 Guidance for selecting sewermen  
General guidance for selecting sewermen depending on the type of duties is given in Appendix A . 
 
5. Precautions  
5.1 Precautions against gas h azards  
When a sewer or a  manhole is required to be entered for cleaning or clearing an obstruction,  where 
dangerous gas or oxygen deficiencies may be present, both the supervisor and workers shall observe the  
following precautions:  
a) allow no smoking nor open flames and guard against spark;  
 
b) erect warning si gns; 
 
c) use only safety gas -proof electric ligh ting equipment or mirror for reflection of light;  
 
d) test the atmosphere for noxious  gases and oxygen deficiencies. In case of scum formation,  the water and 
sediments in the manhole should be agitated wi th the help of rod or any other suitable instrument fo r 
trapped gases and the manhole should be checked for noxious gases and oxygen deficiencies;  
 DKS 2868:  2018  
 
© KEBS 2018 — All rights reserved    3 e) if the atmosphere is normal, workers  may enter with a safety belt att ached and with at least two men 
availab le at top. For extended jobs, the gas tests shall be  repeated every three minutes while men are in 
the sewer;  
 
f) if oxygen deficiency or noxious ga s is found, the structure shall be ventilated with pure air by ke eping open 
at least one manhole cover each on upstream and dow nstream side for quick exist of toxic gases or by 
forced ventilati on using a portable blower. The gas tests  shall be repeated before entering . Adequate 
ventilation shall be maintained during the  work and the gas test shall be repeated every  three minutes.  
 
g)  if the gas or oxygen  deficiency is pr esent and it is not practicable to vent ilate adequately before workers 
enter , a hose masks shall be worn and extreme care shall b e taken to avoid all sources of ignition. Workers 
shall be taught  how to use the hose equipment. In these cases, they shall alway s use permissible safety 
lights (not ordinary flash lights) rub ber boots or non -sparking shoes and non -sparking tools;  
 
h) workers  descending a manhole s haft to inspect or clean sewers shall try each ladder step or rung carefully 
before putting the full weight on it to guard ag ainst insecure fastening due to corrosion of the rung at the 
manhole wall. When work is going on in deep sewers, at least two men  (topmen)  shall be available for 
lifting workers from the manhole in the event of serious injury; and  
 
i) portable air blowers, for ventilating manhole, are recommended for all tank, pit or manhole work where 
there is a possibility of presence of noxious gas, vapours or oxygen deficiency. The motor of these air 
blowers shall be of weatherproof and flameproof type, compress ion - ignitions - diesel type (without 
sparking plug ). These shall be placed not less than 2 m away from the opening and on the leeward side 
protected from wind so that they will no t serve as a source of ignition for any inflammable gas which may 
be present. Forced type ventilation should be provided by blower located at ground level with suitable 
flexible ducting to displace out air from the manhole.  
 
5.2 Precautions a gainst infection  
The personnel working in  sewerage maintenance systems are pr one to infections . The employer should 
therefore ensure that the following precautions are  taken:  
 
a) the workers should be sensitized  about the hazards of waterborne diseases such as typhoid and cho lera 
through sewage and tetanus through cuts and wounds. Cuts and grazes should be covered  with waterproof 
plasters. Ef fective immunization of workers against diseases such as typhoid, c holera, tetanus, HBV, etc., 
should be done by vaccination;   
 
b) the importance of personal h ygiene should be emphasized and the worker s should be instructed  to keep 
finger nails short and well -trimmed , wash hands with s oap and hot water before taking food or smoking 
and to keep  fingers out of nose, mouth and eyes, because the hands carry most infection;  
 
c) use of rubber gloves shall be in sisted so that sewage or sludge does not come in direct con tact with hand. 
Before starting work, skin likely to be exposed to sewage should be covered with barrier cream.  
 
d) the worker s should be provided with a complete change of work  clothes to be worn during working hours. 
Gum boots should also be provided for the workers;  
 
e) when the work is completed, workers should thoroughly wash all contaminated parts of the body.  
 
6. Safety equipment  
The work supervisor shall ensure that every  sewerman  is equipped with the foll owing equipment for own 
protection while at work.  
a) safety helmet prefer ably with cap lamp (explosion proof ); 
b) safety belt;  
c) protective gloves;  
d) overall, heavy coat or other  heavy duty protective clothing , preferably  waterproof;  
e) knee or thigh length safety boots with toe protection and ant i-spark studs;  
f) gas masks and breathing apparatus;  
g) eye protectors;  
h) portable lighting equipment;   
                                                                          4  © KEBS 2018 — All rights reserved  i) non-sparking tools;  
j) portable air blowers;  
k) gas test equipment , such as safety candle lamps, Davy’s safety  
lamps, lead acetate papers and electronic gas detectors; and  
l) first aid equipment.  
 
7. Permit to work  
An employer shall issue a permit to work to any employee, likely to be exposed to hazardous work 
processes or hazardous working environment in order to secure the safety and health of the employee.  
Such work and work environment that may require permit to work include:  
a)   entry to or work in confined spaces;  
b) working in an environment with the likelihood of contact with hazardous material or toxic gas exposure.  
 
The permit to work procedure should be used:  
i. to ensure that personnel working in the restricted area are aware  of the hazards involved,  the 
identity, n ature and extent of the work to be done and precautions to be taken.  
 
ii. to ensure that a formal check is undertaken to confirm that the hazard involved is within the 
accepted limit and that appropriate PPEs are provided before workers are allowed to enter or  work 
in the restricted area;  and 
 
iii. if the work requires the authorization of more than one person, or there is a time limit on entry.  
 
8. Procedure for working in a sewer  
To ensure proper safety standards, the work supervisor  shall ensure that the following steps are  followed:  
8.1 before leaving the d epot   
a) all appropriate and adequate safety equipment  should be checked and verified for usability;  and 
b) all anticipated potential hazards should be analysed based on the work, working location and work 
conditions.  
 
8.2  on arrival at the s ite 
a)  adequate road markings  should be set up ; and  
b)  the system (guarding all openings) on a  sewer open up should be ventilated , that is,  
i. the working manhole,  
ii. next manhole upstream, and  
iii. next manhole downstream.  
NOTE - This is minimum requirement. Use may be made of air blowers, if  necessary.  
 
8.3  entry p rocedure  
a) the topmen shall be determined before entry of the workers into the sewer.  
b) gas shall  be checked  (if in doubt - stay out);  
c) every worker shall  tie safety belt and rope before entering;  
d) ladders, step iron, etc., should be checked  for defects (if in doubt,  use a rope attached to the safety belt);  
e) safety ropes, spare lamps, breathing sets,  shall be kept  close  to working area for immediate use in case 
of emergency; and  
f) if considered safe,  workers should  be allowed to enter sewer.  
NOTE  - In deep sewers, the waste water  level in the sewers should be checked before  entering.  
 
8.4  Working i nside the s ewer   
a) the presence of gas should be checked every three minutes, and  
b) the topmen  should call to the man working in th e sewer every three minutes.  Every message shall be 
acknowledged.  
. 
8.5  Completion of w ork 
a) after the work is completely done, the t op men should be informed ;  
b) ganger ( normally last men out) should check and ensure  that all tools, ropes, etc., are out and that the 
sewer is clear;  
c) all grids, guardrails, manholes covers should be replaced  
d) road safety signs should be removed and site cleared;  
e) workers should wash thoroughly before eating or smoking.   DKS 2868:  2018  
 
© KEBS 2018 — All rights reserved    5  
9. Gas e mergency  
a) If a gas emergency occurs everyone should immediately put on their escape sets ( breathing apparatus) 
and alarm raised.  
 
b) The top men are trained rescuers and they should let down the rescue sets and wait the men working in 
sewer to come out. The top men sha ll attempt to rescue the man inside sewer with all the equipment at 
their disposal.  
 
c) If there is a casualty, he should be propped up out of water in a comfortable position. Immediatel y call  
the emergency services ( ambulance, fire brigade). When the victim has gas mask put on if  he is 
breathing , a rescuer should always be with him because he may vomi t thereby choking the supply of 
oxygen.  
    
Guidelines for giving first -aid to a gas victim are given below:  
i) remove the victim  to place with  fresh air as soon as possible;  
ii) apply artificial respiration with an oxygen resuscitation if he is not breathing. If one is not available, apply 
mouth to mouth breathing; and  
iii) keep the victim  lying down on a recovery position and wait for an ambulance.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  
                                                                          6  © KEBS 2018 — All rights reserved  APPENDIX A  
GUIDANCE FOR SELECTION OF SEWERMEN  
A-1. REQUIREMENTS FOR DUTIES NOT REQUIRING ENTRY  INTO CONFINED 
SPACE  
A-.1.1 No specific requirements excep t a routine medical examination shall be made. Those with the 
following dis abilities shall not be selected as any of the disease involves risks to th e health and safety of both 
the prospective employee and/or other employees:  
a) History of fits, blackouts, fainting attacks;  
b) Chronic skin disease; and  
c) Meniers disease or diseases invol ving loss of balance.  
 
A-2. REQUIREMENTS FOR DUTIES REQUIRING ENTRY INTO  CONFINED SPACE  
A-2.1 Persons considered for employm ent in confined spaces shall be physically fit and capable of 
understanding train ing given. Those with the undernoted disabilities s hall not be recruited for this type of 
work and those who contract these should cease to be employed in this  capacity:  
a) A history of fits, blackouts or fainting attacks;  
b) A history of heart disease or disorder;  
c) High blood pressure;  
d) Asthma, bronchitis or a shortness of breath on exertion;  
e) Deafness;  
f) Meniers disease or disease involving giddiness or loss of balance;  
g) Claustrophobia  or nervous or mental disorder;  
h) Back pain or joint trouble that would limit mobility in confined spaces;  
i) Deformity or disease of the  lower limbs limiting movement;  
j) Chronic skin disease;  
k) Serious defects in eyesight; and  
l) Lack of sense of smell.  
 
A-2.1.1 Employees should be medically re -examined at reasona ble intervals, taking into account the 
person’s age and duties.