Bottled natural mineral water — Specification BOTSWANA  STANDARD  BOS 262:2023 
Edition  2.0 BOS 262:2023 
BOTSWANA BUREAU OF STANDARDS  
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I
CS 13.060.20 
Published in Botswana  
BOS 262:2023  
Edition 2. 0 
©
 BOBS [2023] – All rights reserved 
i Contents 
Pa ge 
Foreword  ............................................................................................................................................................ ii 
1 Scope  ......................................................................................................................................................... 1 
2 Normative references  ................................................................................................................................. 1 
3 Terms and definitions  ................................................................................................................................. 2 
4 Requirements  ............................................................................................................................................. 2 
4.1 Requirements for the untreated product  ............................................................................................ 2 
4.2 Requirements for the finished product  ............................................................................................... 4 
4.3 General requirements  ........................................................................................................................ 5 
5 Sampling of the finished product  ................................................................................................................ 6  
6 Packaging and labelling of bottles  .............................................................................................................. 6  
6.1 Packaging  .......................................................................................................................................... 6 
6.2 Labelling ............................................................................................................................................. 6 
Annex A (normative)  Sampling and compliance with the standard  .................................................................. 8 
Annex B (informative)  Recommended test methods for use in testing  ............................................................ 9 
Bibliography ………………………………………………… ……………………………………………………… 10  BOS 262:2023  
Edition 2. 0 
ii Foreword 
This Botswana standard was approved by the Technical Advisory Committee of the Standards Council on 
2023-03-28.  
The Botswa na Bure au of Standards ( BOBS) w as es tablish ed under t he Standards A ct No. 16 of 19 95 with a 
primary r esponsibility of pr eparing Botswana standards. 
This B otswana Standar d is a revision of, c ancels and r eplaces B OS 262:2011. 
During the review of t his s tandard, t he following organizations w ere directly r epresent ed in the Technical 
Committee, EM D 2 – Water Q uality : 
Technical C ommittee, EMD 2 – Water Q uality T echnical C ommittee: 
Wat
er Utilities Corporation    Mr    R     Samaxa    ( Chairperson)  
Botswana Bureau of Standards      Mr    K    Setiko        (Technical Secretary)  
Botswana Bureau of Standards      Ms   L    Ditlhakeng  
Botswana Bureau of Standards      Mr    K    Marumo  
Chobepure         Mr   M   Lamont  
Debswana Diamond Company Pty (Ltd)      Mr   B    Maswabi  
Debswana Diamond Company Pty (Ltd)      Mr   O     Mabote  
Gaborone Laboratory Services       Mr   R   Bimah  
Leru Water         Ms   J   Motlogelwa  
Ministry of Agricultur e, Ms   T    Mosedame  
Plant Protection Division 
Ministry of Health ,        Ms   N     Leseane  
National Food Control Laboratory  
Ministry of Lands and Water Affairs ,  Ms   K    Tau  
Department of Water and Sanitation 
University of Botswana,     Ms    I    Chibua  
Department of Chemistry  
University of Botswana,      Dr    P     Koosaletse- Mswela  
Department of Environmental Science  
Water Utilities Corporation     Ms     B M onametsi  
© BOBS [ 2023] – All rights reserved  BOS 262:2023  
Edition 2. 0 
©
 BOBS [2023] – All rights reserved 
1 Bottled natural mineral water — Specification 
1 Scope  
This Botswana Standard specifies the physical, chemical and microbiological requirements for bottled natural 
mineral water for human consumption, bottled at the source. It also specifies permissible treatments and the requirements for bottling and labelling.  
NOTE  The water may be offered as bottled non- carbonated (still) natural mineral water or as bottled carbonated 
(sparkling) natural mineral water.  
This standard excludes water that contains sugar, sweeteners, flavourants or other additives.  
2 Normative references  
The following normative documents are indispensable for the application of this standard. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. Botswana Bureau of Standards (BOBS) maintains registers of currently valid standards.  
AOAC official method 991.07, Nitrogen and phosphorus containing pesticides in finished drinking water – Gas 
chromatographic method.
1 
APHA method 6630 B2, Organochlorine pesticides – Liquid – liquid extraction gas chromatographic method.  
BOS 306, Water quality – Bottled water – Code of hygienic practice. 
BOS 686, Requirements for a Hazard Analysis and Critical Control Point (HACCP) System  
BOS ISO 6461- 1, Water quality – Detection and enumeration of the spores of sulfite- reducing anaerobes 
(clostridia) – Part 1: Method of enrichment in a liquid medium.  
BOS ISO 6461- 2, Water quality – Detection and enumeration of the spores of sulfite- reducing anaerobes 
(clostridia) – Part 2: Method of membrane filtration.  
BOS ISO 9308 -1, Water quality – Detection and enumeration of Escherichia coli and coliform bacteria - Part 
1: Membrane filtration method.
BOS ISO 9308 -2,  Water quality –- Determination and enumeration of Escherichia coli and coliform bacteria - 
Part 2: Liquid enrichment  method.  
BOS ISO 10304 -1, Water quality – Determination of dissolved fluoride, chloride, nitrite, orthophosphate, 
bromide, nitrate and sulfate ions, using liquid chromatography of ions - Part 1: Method for water with low 
contamination.  
BOS ISO 15553 , Water  quality – Isolation and identification of Cryptosporidium oocysts and Giardia cysts from 
water.  
1 In AOAC International. Official methods of analysis. 17th edition vol. 1. edited by William Horwits. Gaithersburg: AOAC 
International, 2000  
2 In Standard methods for the examination of water and waste water , prepared and published jointly by the American 
Public Health Association, the American Water Works Association and the Water Environment Federation. 19th ed. 1995. BOS 262:2023  
Edition 2. 0 
©
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2 BOS ISO 16266, Water quality – Detection and enumeration of Pseudomonas aeruginosa – Method by 
membrane filtration.   
I
SO 6439, Water quality – Determination of phenol index -4 – Aminoantipyrine spectrometric methods after 
distillation  
ISO 6703-1 , Water quality – Determination of cyanide – Part 1: Determination of total cyanide. 
ISO 7899- 2, Water quality – Detection and enumeration of faecal streptococci – Part 2: Method by membrane 
filtration.  
ISO 8199, Water quality – General guide to the enumeration of micro – organisms by culture. 
3 Terms and definitions  
3.1 acceptable: allowable to the authority administering this standard, or to the parties concluding the 
purchase contract, as relevant  
3.2 batch: bottled natural water that is processed during a specified period of production in a single 
bottling plant  
3.3 bottle : a container that is made of glass, a plastic material, or tin plate or other suitable material, and 
that (in each case) is capable of being sealed with a closure 
3.4 carbonated (sparkling) natural mineral water : natural water that has been made effervescent by the 
addition of carbon dioxide  
3.5 defective: a bottle or its contents that does not comply in one or more respects with the relevant 
requirements of the standard 
3.6 lot: product of the same description and from the same batch, in bottles of the same size and type, 
from the same manufacturer, and submitted at anyone time for inspection and testing  
3.7 mineral content: the concentration of mineral salts, trace elements and other inorganic constituents 
present, normally expressed in milligrams per litre  
3.8 natural: pertaining to the product covered by this standard, descriptive of water that has undergone 
only treatment permitted by this standard  
3.9 non-carbonated (still) natural mineral water : water that, by nature, does not contain free carbon 
dioxide in excess of the amount necessary to keep dissolved the hydrogen carbonate salts that are present 
in the water  
3.10 product: bottled water that complies with the requirements given in this standard and shall not contain 
sugars, sweeteners, flavourants, or other foodstuffs  
3.11 source: the point at which the product (see 3.10) is extracted from subterranean water -bearing strata  
4 Requir ements  
4.1 Requirements for the untreated product  
4.1.1  Microbiological requirements  
When tested, at the frequencies stated in column 3 of Table 1, in accordance with the methods given in column 
4 of Table 1 against determinants in column 1, the untreated product shall not contain amounts greater than the limits given in column 2.  BOS 262:2023  
Edition 2. 0 
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3 Table  1 — Microbiological determinants’ requirements  
Determinant  Acceptable limit  Frequency of testing  Test method  
Total coliform s Absent in 100 ml  Initially then weekly  BOS ISO 9308 -1 or 
 BOS ISO 9308 -2 
Faecal coliform s (including 
Escherichia coli ) Absent in 100 ml  Initially then weekly  BOS ISO 9308 -1 or 
BOS ISO 9308 -2 
Total viable colony a100 per 1 ml (maximum)  Initially then weekly  ISO 8199  
Enterococcu s Absent in 100 ml  Initially then weekly  ISO 7899 -2 
Moulds Absent in 100 ml  Initially then weekly  ISO 8199  
Pseudomonas aeruginosa  Absent in 100 ml  Initially then monthly  ISO 16266  
Clostridium spores  Absent in 100 ml  Initially then monthly  ISO 6461 -1 or 
ISO 6461- 2  
Cryptosporidium and Giardia  
(oo)cysts  Absent in 10 litres During rainy season or 
when there is an outbreak 
of water borne diseases  BOS ISO 15553  
a Total viable colony shall be tested at 22 °C and 37 °C within 24 h after bottling with the water being maintained at   4 
°C ± 3 °C during this period  
4.
1.2 Contaminants  
When tested, at the frequencies stated in column 4 of Table 2, in accordance with the methods given in column 
5 of Table 2, the product in its bottled state shall not contain amounts greater than the limits given in column 3 of Table 2.  
Table  2 — Contaminants  
Contaminant  Risk 
category  Acceptable limit  Frequency of testing  Test method  
Phenolic compounds  health  <5 µg/  ℓ Initially then every six 
months  BOS ISO 6439  
Organochlorine 
pesticides and PCB’s  health  Not detectable aInitially then every six 
months  APHA method 
6630 B  
Organophosphate 
pesticides  health  Not detectable aInitially then every six 
months  AOAC method 
991.07  
Cyanide  health  Not more than 0.07 mg/  
ℓ, calculated as CN  Initially then every six 
months  ISO 6703 -1 
Nitrite  health  Not more than 0.01 mg/  
ℓ, calculated as N  Initially then every six 
months  BOS ISO 
10304-1 
NOTE Test methods that deliver equal or better results may be substituted for those listed in column 5.  
a  Not detectable by the method specified  
4.
1.3 Physical and chemical requirements  
The untreated product shall be tested for the constituents listed in Table 3 and Table 4, at the frequency stated.  
4.2 Requirements for the finished product  
4.2.1  Permissible treatments  
The following treatments are permitted: BOS 262:2023  
Edition 2. 0 
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4 a)separation from unstable constituents, such as compounds containing iron, manganese, sulphur or
arsenic, by decantation or by filtration using a filter greater than 0.45 µm (or by both), accelerated, ifnecessary, by previous aeration;
b)the removal of carbon dioxide from the water, and the addition of carbon dioxide to the water, either direct,or after an initial removal stage; and
c)ultraviolet light treatment.
The treatments provided for in 4.2.1 (a), (b) and (c) may only be carried out on condition that the mineral content and the essential constituents that give the product properties are not modified. 
4.2.2  Physical and chemical requirements  
For Table 3 and Table 4, when tested in accordance with the methods given in Annex B, the product, in its 
bottled state,  shall not contain amounts greater than the limits given in column 3 for the determinants specified 
in column 1. The frequency of testing shall be as specified in column 4.  
Table  3 — P hysical and macro chemical determinants’ requirements  
Determinant  Risk category  Limits 
(maximum)  Frequency of 
testing 
Odour  aesthetic  ˂ 5 TON  Daily  
pH health  5.5 to 9.5  for still water  
4.0 to 9.5 for carbonated 
water  Daily  
Colour  aesthetic  15 TCU  Daily  
Taste  ˂ 5 FTN  Daily  
Turbidity  aesthetic / operational  5 NTU  Daily  
Electrical conductivity  aesthetic  1500 µS/cm  Daily  
Total Dissolved Solids  aesthetic  1 000 mg/ ℓ Initially then quarterly  
Calcium  as Ca  aesthetic / operational  150 mg/ ℓ Initially then quarterly  
Chloride  as CI  aesthetic  200 mg/ ℓ Initially then quarterly  
Magnesium  as Mg  aesthetic / health  70 mg/ ℓ Initially then quarterly  
Potassium  as K operational / health  50 mg/ ℓ Initially then quarterly  
Sodium  as Na  aesthetic / health  200 mg/ ℓ Initially then quarterly  
Sulfate  as SO 4 health  250 mg/ ℓ Initially then quarterly  
T
able 4 — Limits for chemical requirements: Micro determinants  
Determinant  Risk category  Limits  
(maximum)  Frequency of testing  
Aluminium as Al  health  0.20 mg/ ℓ Initially then quarterly  
Antimony as Sb  health  0.020 mg/ ℓ Initially then quarterly  BOS 262:2023  
Edition 2. 0 
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5 Table 4 continued 
Determinant  Risk category  Limits  
(maximum)  Frequency of testing  
Arsenic as As  health  0.01 mg/ ℓ Initially then quarterly  
Barium as Ba  health  1.0 mg/ ℓ Initially then quarterly  
Borate as total Boron  health  5 mg/ ℓ Initially then quarterly  
Cadmium as Cd  health  0.003 mg/ ℓ Initially then quarterly  
Chromium as Cr  health  0.05 mg/ ℓ Initially then quarterly  
Copper as Cu  health  2.0 mg/ ℓ Initially then quarterly  
Fluoride as F  health  0.7 mg/ ℓ Initially then quarterly  
Iron as Fe  aesthetic /operational  0.3 mg/ ℓ Initially then quarterly  
Lead as Pb  health  0.01 mg/ ℓ Initially then quarterly  
Manganese as Mn  aesthetic  0.1 mg/ ℓ Initially then quarterly  
Molybdenum  health  0,07 mg/ℓ  initially and annually  
Mercury as Hg  health  0.006 mg/ ℓ Initially then quarterly  
Nickel as Ni  health  0.07 mg/ ℓ Initially then quarterly  
Nitrate as NO 3 health  50 mg/ ℓ a Initially then quarterly  
Selenium as Se  health  0.01 mg/ ℓ Initially then quarterly  
Sulfide as H 2S health  0,1 mg/ℓ, initially and quarterly  
Surface active agents  health  Below limit of 
quantification  initially and quarterly  
Zinc as Zn  health  3.0 mg  ℓ Initially then quarterly  
Organic matter calculated 
as O 2 absorbed  health  3.0 mg/ℓ Initially then quarterly  
a 50 mg /ℓ as NO 3 converts to 11 mg/ℓ as N.  
4.
2.3 Microbiological requirements  
Refer to clause 4.1.1.  
4.3 General requirements  
4.3.1  Hygiene  
The product covered by the provisions of this standard shall be prepared in accordance with the applicable 
clauses of the BOS 306 and BOS 686.  
4.3.2  Taste and odour  
The product shall have acceptable taste and a non- objectionable odour. The taste of the product shall be in 
accordance with any claim made or implied.  BOS 262:2023  
Edition 2. 0 
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6 4.3.3  Net volume of the product 
The net volume of the product shall comply with the relevant  regulations.3) 
4.3.4  Freedom from defects 
The product shall comply with the test for turbidity under normal conditions of storage. Dust, fibre particles, 
surface film or scum, sediment and other foreign matter shall not be present.  
4.3.5  4.3.5  Carbonation  
The carbon dioxide used shall be of acceptable food grade (> 99.9 % purity).  
4.3.6  Shelf life 
The composition and preparation of the product shall ensure a shelf life of 1 year under the storage conditions recommended by the manufacturer.  
5 Sampling of the finished product  
The sampling plan given in Annex A shall be followed.  
6 Packaging and labelling of bottles 
6.1 Packaging 
The bottled product shall be packaged in sealed retail containers that will prevent possible adulteration or contamination of the water . 
6.2 Labelling  
The bottled water shall be labelled as per the relevant  regulation requirements .4) 
Applied labels on bottles shall  
a)be clean, neat and securely attached,
b)not be super -imposed on other labels or on printed matter print ed direct on the bottles,
c)not be applied by any person other than the manufacturer or the authorized agent and
d)have the producing factory or name of manufacturer of the bottled water.
6.2.1  The name of the product  
The name of the product shall be ‘Natural Miner al Water’.  
6.2.2  Specific composition  
The composition of the product shall be declared in advertising and on the label. The concentration of the following constituents, in units of  milligrams per litre (mg/ ℓ), shall be included in the declaration:  
Calcium ………………………………………………………. as Ca 
3)For Botswana Weight and Measures Act Chapter 43:6 shall apply
4)F
or Botswana Food Control Act (Statutory Instrument No. 83 of 2002 and Labelling of Pre-packed Foods Regulations
(Chapter 65:05) shall apply .BOS 262:2023  
Edition 2. 0 
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7 Magnesium…………………………………………………….as Mg 
Sodium………………………………………………………….as Na Potassium………………………………………………………as K Chloride…………………………………………………………as CI 
Sulfate…………………………………………………………..as S0
4 
Total alkalinity………………………………………………….as Ca CO 3 
Nitrate…………………………………………………………..as NO 3 
Fluoride…………………………………………………………as F 
In addition, the amount of total dissolved solids shall be declared in milligrams per litre (mg/ℓ), and 
the pH value shall be declared in pH units.  
6.2.3  Carbonation  
The label shall state whether the product is non- carbonated (‘still’) or carbonated (‘sparkling’).  
6.2.4  Net contents  
The net contents shall be declared by volume in the metric system (SI units).  
6.2.5  Name and address  
The location of the source, the name of the source and the name, telephone and physical address of the 
manufacturer shall be declared.  
6.2.6  Lot identification  
Each bottle shall be embossed or otherwise permanently marked, in code or otherwise, to identify the following:  
a)lot;
b)date of manufacture; an d
c)ex
piry date or best before or sell by or use by.
The use of a lot code is permissible only if the key to the code is disclosed to the authority administering this standard.  
6.2.7  Additional labelling requirements 
If the product has been subjected to a treatment in accordance with 4.2.1, the treatment shall be declared on the label.  
6.2.8  Labelling prohibitions  
6.2.8.1  No claims concerning medicinal (preventative, alleviative or curative) or other beneficial effects 
relating to the health of the consumer shall be made in respect of the properties of the product covered by 
this standard.  
6.2.8.2  The name of a locality, village or specified place may not form part of the trade name unless it 
refers to product collected at the place designated by that trade name.  
6.2.8.3  The use of any statement or of any pictorial device which might create confusion in the mind of the 
public or in any way mislead the public about the nature, origin, composition and properties of the product 
put on sale is prohibited.  BOS 262:2023  
Edition 2. 0 
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8 Annex  A 
(normative)  
Sampling and compliance with the standard 
A.1 Sampling of the finished product
A.1.1  General
The sampling procedure given in A.1.2 to A.1.4 shall be applied to determine whether a lot, submitted for 
inspection and testing, complies with the requirements of the standard. The samples taken shall be deemed to represent the lot.  
A.1.2  Sample for physical examination and for the inspection of containers
After inspection for compliance with 6.1 and 6.2, from the lot, take at random the number of containers, shown in column 2 of Table A.1.  
Table  A.1 — Sampling plan  
d)Lot size
(
number of containers)  Sample size for 
physical examination  
(number of containers)  Sample volume for 
chemical analysis  
(litres)  Sample size for micro -
biological examination  
(number containers) a
0 – 5 000  3 3 3 
5 000 – 12 500  6 3 3 
12 501 – 25 000  9 3 3 
25 001 – 50 000  16 3 3 
50 001 upwards  30 3 3 
NOTE  For examination for parasites, 10 litres  of product is required  
a Minimum  volume of each container to be 500 ml.  
A.1.3  Sample for chemical analysis
After inspection for compliance with 6.1 and 6.2, from the lot, take at random the number of containers that will deliver the volume given in column 3 of Table A.1.  
A.1.4  Sample for microbiol ogical examination
After inspection for compliance with 6.1 and 6.2, from the lot, take at random one container at the beginning of the bottling cycle, one container in the middle of the cycle and one container at the end of the cycle.  
A.2 Compliance with the standard
The lot shall be deemed to comply with the relevant requirements of the standard if, after inspection and testing of the samples taken in accordance with A.1.2 to A.1.4 inclusive, no defect is found.  BOS 262:2023  
Edition 2. 0 
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9 Annex  B 
(informative)  
Recommended test methods for use in testing 
B.1 General
The following test methods listed in Table B1 are recommended for use in testing, since they can offer the 
required accuracy.  
Table  B.1 — Recommended test methods for use in testing  
Determinant  Test method  
Aluminum  
Alkalinity  
Arsenic  
Cadmium  
Calcium  
Chloride  
Chromium  
Cobalt  
Colour  
Copper  
Dissolved solids  
Electrical conductivity  
Fluoride  
Magnesium  
Manganese  
Mercury  
Nickel  
Nitrate  
Nitrite  
Organic matter  
pH value  
Potassium  
Selenium  
Sodium 
Sulphate  
Taste Turbidity  
Zinc BOS ISO 12020  
BOS ISO 1657  
BOS ISO 11969  
BOS ISO 5961 / BOS ISO 8288  
BOS ISO 7980  
BOS ISO 10304 -1 
BOS ISO 9174  
BOS ISO 8288  
BOS 38  
BOS ISO 8288  
BOS 125  
BOS ISO 7888  
BOS ISO 10304 -1 
BOS ISO 7980  
BOS 123 / BOS 124  
BOS ISO 5666  
BOS ISO 8288  
BOS ISO 10304 -1 
BOS ISO 10304 -1 
SANS 5220  
BOS ISO 10523  
BOS ISO 9964 -3 
BOS ISO 9965  
BOS ISO 9964 -3 
BOS ISO 10304 -1 
SM 2160 B a) 
BOS 39  
BOS ISO 8288  
a)Standard methods for examination of water and waste water , American Public Health Association,
American Water Books Association and Water Environment Federation, Washington DC, 21st ed,
2005.BOS 262:2023  
Edition 2. 0 
Bibliography  
[1] Food Control Act Regulations (Statutory Instrument No. 83 of 2002)
[2] Labelling of Pre- packed Foods Regulations (Chapter 6 5:05)
[3] Weight and Measures Act (Chapter 43:06)