DRAFT ZANZIBAR STANDARD  
 
 
Seaweed  powder  - Specification  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ZANZIBAR BUREAU OF STANDARDS  
 
 
©ZBS 2022 - All rights reserved           First Edition  
 
 
 
 
 
WGD 6: 2021  
PCD 436:2022  
ICS 67.120.30    WGD 6: 2021  
 
©ZBS 2022 - All rights reserved  
 ii 
 Foreword  
 
This draft Zanzibar  National  Standard has been developed Fish and fisheries, meat, poutry and their 
products  Standard Technical committee (TCFA 6). In accordance with ZBS general procedures, this draft 
standard is presented to the public in order to receive any technical and editorial comment concerns.  
 
The Zanzibar Bureau of Standard (ZBS) was established under Standard Act No. 1 of 2011.   
 
 
Zanzibar Bureau of Standards (ZBS)  
PO Box 1136  
Zanz ibar 
Tel:  +255 24 2232225  
Fax: +255 24 2232225  
E-mail: info@zbs.go.tz  
Web: www.zbs.go.tz   
 
PCD 436: 202 2 
 
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 Seaweed  powder - Specification  
 
1 Scope  
This draft standard specifies requirements, method of sampling and test of Seaweed powder intended 
for human consumption  or for  industrial use . 
2 Normative references  
The following referenced documents are indispensable for the application of this working dr aft Zanzibar 
National Standard. For dated references, only the edition cited applies. For undated references, the 
latest edition of the referenced document (including any amendments) applies.  
AOAC 952.13, Arsenic in food — Silver diethyldibocarbamate metho d 
 
AOAC 972.23, Lead in fish —– Atomic absorption spectrophotometric method  
 
 AOAC 973.34, Cadmium in food — Atomic absorption spectrophotometric method  
 
AOAC 983.20, Mercury (methyl) in fish and shellfish — Gas chromatographic method  
 
CODEX STAN 193, Codex general standard for contaminants and toxins in food and feed  
 
ZNS 61 , Packaging and labeling of food  
 
ZNS 94, Rounding off numerical values  
 
PCD 43 5, Dried raw seaweed - Specification  
PCD 43 7, Code of Good Aquaculture Practices (GAqP) for Seaweed  
EAS 39, Hygiene in the food and drink manufacturing industry — Code of practice  
3 Terms and definitions  
For the purposes of this Standard, the following (terms and) definitions shall apply.  
3.1  
seaweed  
cluster of macroscopic, multicellular, benthic marine algae ; includes some members of the red, brown 
and green algae.  
 
3.2  
seaweed powder  
product obtained by grinding clean dried raw seaweed  either bleached or unbleached   
 
3.3  
bleaching  
process of removing natural colour from  wet/dried raw seaweed  
 
3.4  
foreign matter  
all organic and inorganic material  
 
3.6.1  
inorganic matter  
stones, shells, sand,  glass, and other mineral matter  
 
3.6.2  
organic matter  
any animal or plant matter  (filth, rodent)  other than  seaweed powder  
 
  
 
PCD 436: 2022  
 
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 3.8  
filth 
impurities of animal origin including dead insects  
 
3.9  
contaminants  
any biological or chemical agent, foreign matter, or other substances not intentionally added to seaweed  
powder  which may compromise food safety and suitability.   
3.10 
food grade   material   
material  which shall safeguard the hygienic, safety, nutritional, technological, and organoleptic qualities 
of the product  
3.11 
sifting  
particle size separation by sieving and aspiration of milled products  
 
4 Requirements  
4.1 Raw material  
 
The seaweed powder  shall be made from dried raw seaweed  conforming to the requirements given in 
PCD 435. 
 
4.2 General requirements  
 
Seaweed powder  shall 
 
a) be from one species only   
b) have characteristic appearance, colour  and  taste  of seaweed  powder ; 
c) be free from abnormal flavours  and odours;  and  
 
d) free from living insects, worms, filth, and foreign matter;  
 
4.3 Specific requirements  
 
Seaweed powder shall comply with the requirements given in Table 1 when tested in accordance with 
the test methods specified therein   
Table 1 : Specific requirements for  Seaweed powder  
S/No  Characteristics  Requirement  Test methods  
i.  Moisture content (MC), (% max)  13.5 Annex A  
ii.  Acid insoluble ash, % max.  1.5 ISO 5985  
iii.  Residue on sieving  
through 1000 -micron  
sieve,  %, m/m,  
max.    
  
fine 0.5 
AOAC 965.22  coarse 
N/A 
iv.  Salt as KCl, (% max)  25 Annex B  
                           N/A means Not applicable  
 
5 Food additives  
 
Seaweed powder shall be free from added colouring matter, flavouring substances and 
preservatives.   
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 6 Contaminants  
6.1 Heavy Metal contamination  
 
seaweed powder shall comply with those maximum heavy metal limits  given in Table 2 when tested in 
accordance with test methods specified therein.  
Table 2: Maximum limits for heavy metal contaminants in seaweed  powder  
 
S/N  
Parameter Maximum 
limit  
mg/kg  
Test method 
i.  Arsenic  (As) 3 AOAC  952.13  
ii.  Lead (Pb)  5 AOAC  972.23  
iii.  Mercury  1 AOAC  983.20  
iv.  Cadmium ( Cd) 1 AOAC  973.34  
 
6.2 Pesticide residues  
 
Seaweed powder  shall comply with those pesticide maximum residues limits established in the Codex 
pesticide residues in food online data base   and/or competent authority for this commodity .  
7 Hygiene  
Seaweed powder  shall be produced, transported and /or distributed in accordance with requirements 
set according to code of aquaculture practice  PCD 437 and EAS 39 . 
8 Weights and measures  
Seaweed powder  shall be packed in accordance with the weights and measures regulations of Zanzibar . 
 
9 Packaging and labelling  
 
9.1 Packaging  
Seaweed powder  shall be packaged in food grade material that secures the integrity and the safety of 
the product.  
 
9.2 Labelling   
 
9.2.1  In addition to the labelling requirements specified in ZNS 61, the containers shall be also legibly 
and indelibly labelled with the following: - 
 
a) name of the product  ‘Seaweed powder’ ;             
b) species  name;  
c) brand name/trade name  if any ;  
d) name and address of producer/packer/distributor;  
e) storage condition;  
f) manufacturing date;  
g) best before date;  
h) lot identification or batch or code number;  
i) country of origin;  
j) net weight in metric unit;  
k) instruction for disposal of used packaged material ; and  
 
PCD 436: 2022  
 
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 l) declaration of bleaching process if applicable . 
 
9.2.2  The language on the label shall be ‘Kiswahili’ and/or English. Additional language may be used 
depending on the designated market.  
 
10 Sampling  
 
Sampling of Seaweed powder shall be done according  to Annex C.  
 
PCD 436: 202 2 
 
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 Annex  A 
(normative)  
 
Determination of moisture  
A.1 Apparatus  
A.1.1  Electric oven , maintained at 1050 C ± 1 0 C  
A.1.2  Moisture dish , made of porcelain, silica, glass or aluminium  
A.1.3  Desiccator  
A.2 Procedure  
Weigh accurately about 5 g of the prepared sample  in the previously weigh ed dried moisture dish,  
Place the dish in the oven maintained at 105 oC ± 1oC for 4 h our.  
Cool in the desiccator and weigh.  
Repeat the process of drying, cooling and weighing at 30 -min intervals until a constant mass, m, is 
obtained.  
A.3 Calculation  
Moisture, percent by  mass, =  
where  
M is the mass, in grams, of the dish with the sample before drying;  
m1 is the mass, in grams, of the dish with the sample after drying to constant mass; and  
m2  is the mass, in grams, of the empty dish.  
 
 
 
 
 
 
 
 
 
()
()21 100
mMmM
−− 
 
PCD 436: 2022  
 
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 Annex B 
(normative)  
Determination of salt (as KCl)  
 
D.1 Determination of  salt as KCl  
 
D.1.1  Get a one (1) kilogram representative sample of the  seaweed powder  material;  
 
D.1.2  Weigh 250 g into a 2 -L beaker;  
 
D.1.3  Add about 900 ml of distilled water, soak the seaweed powder overnig ht salt. Remove the 
seaweed, stir the solution very well to completely dissolve the salt;  
 
D.1.4  Decant the solution into a 1 -L volumetric flask and dilute to volume distilled water  
 
 
D.1.5  Mix the so lution well and measure a 50 ml aliquot into a 250 -ml volumetric flask;  
 
D.1.6  Dilute to volume with distilled water. Mix well and measure a 10 ml aliquot into an Erlenmeyer 
flask;  
 
D.1.7  Add 5 drops of K 2CrO 4 and titrate with standard 0.100 N AgNO 3 to end point (tinge of orange 
brown);  
 
D.1.8  Calculate % salt (as KCl) using the following formula:  
 
% salt (as KCl)= 𝑉 Ag𝑁𝑂 3×𝑁 Ag𝑁𝑂 3×74.50
1000
250 ×50
1000×10
250   ×100 
 
 
 
 
 
 
 
 
 
 
 
  
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 Annex C 
(normative)  
Sampling  
 
E.1  Definition of terms  
 
E.1.1   
bulk sample  
quantity of seaweed powder  obtained by combining and mixing the primary sample taken from a specific 
lot. 
 
E.1.2   
consignment  
quantity of seaweed powder  dispatched or received at one time and covered by a particular contract or 
shipping document. It may be comp osed of one or more lot.  
 
E.1.3   
laboratory sample  
quantity of seaweed powder  removed from the bulk sample and is intended for analyses or other 
examination.  
 
E.1.4   
lot   
composed of seaweed powder  belonging to the same species intended to be uniform in characterist ics 
regarding post harvest treatment.  
 
E.1.5   
primary sample  
a small quantity of seaweed powder  taken from a bag/bale from a lot.  
 
E.2 Sample size  
Sampling shall be done in accordance with the plan specified in Table E.1. 
Table E.1: Sampling plan for seaweed powder  
Lot size (N)  Size of the sample (n)  
1 to 5 bags/bales  All bags/bales  
6 to 49 bags/bales  5 bags/bales  
50 to 199 bags/bales  10% of the bags/bales  
200 bags/bales or more  √𝑛+ 1 
 
Where  n =  number of bags/bales  
 
E.3 Sampling procedure  
The sample shall be taken at random from the lot and in order to achieve this, a random number table 
agreed upon between the buyer and seller should be used. If such table is not available, the following 
procedure shall be adopted:  
  
  
 
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a) Starting from any bag/bale, count the ba gs/bales as 1, 2, 3… etc. up to r and so on. Withdraw 
from the lot every rth bag/bale thus counted for sampling, the value of r is equal to  
𝑟=𝑁
𝑛 
where:  
 
N is the total number of bags/bales in the lot;  
n is the number of bags/bales to be taken (see Table  E.1) 
 
b) If r is a fractional number, its value shall be taken as equal to the integral part of it.  
 
 
E.3.1  When the product is in movement, samples may be taken at the time of loading or unloading of 
the bags/bales. For this purpose, the number of bags/bales to b e taken shall also be in accordance with 
Table 2. The value of r shall be calculated as indicated above, and every rth bags/bales counted during 
loading or unloading shall be removed for sampling.  
 
E.3.2  Take primary samples, by means of an appropriate sampling instrument, from different parts of 
each bags/bales selected.  
 
E.3.3  A series of primary samples should be taken from different positions in the lot.  
 
E.4 Bulk sample  
 
E.4.1  Thoroughly mix all the primary samples taken as described above to form the bulk sample.  
 
E.4.2  The size  of the bulk sample shall be more than three (3) times the quantity of sample required 
to carry out all the tests required in the specification.  
 
E.5 Laboratory samples  
 
E.5.1  Divide the bulk sample into three (3) or more equal parts. Each part thus obtained constit utes a 
laboratory sample; one (1) of these samples is intended for the buyer and another for the seller. The 
third sample, bearing the seals of the buyer and of the seller (or of their representatives) if they were 
present at the time of sampling or of the  person who sampled the lot, shall constitute the reference 
sample to be used in case of dispute between buyer and seller; it shall be kept at a place acceptable to 
both parties.  
 
E.5.2  Samples for test shall be one (1) kilogram.