DRAFT ZANZIBAR NATIONAL STANDARD  
   
 
Henna Paste  — Specification    
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
  
   
  
  
  
 
 
 
ZANZIBAR BUREAU OF STANDARDS  
 
   
©ZBS 202 3 - All rights reserved                                                                                  First edition  
  
 
 PCD 506: 2023  
  
PCD 506: 2023  
ii                                                                                                                ©ZBS 2023  - All rights reserved   
 
  
Foreword  
 
This draft Zanzibar National Standard has been  developed  by the Chemical Products Standards 
Technical Committee (TCC1) . In accordance with ZBS general procedures, this draft standard is 
presented to the public in order to receive any technical and editorial comment concerns.  
 
In the preparation of this standard, assistance was derived from the following source s: 
 
IS 17318, Henna (MEHENDI) Paste i n Shape of Cone and other Allied Packaging — Specification  
ZNS 99 , Henna powder — Specification  
 
Technical Committee Representatives  
 
This draft Zanzibar National Standard was prepared by the Chemical Products Standards 
Technical Committee which consists of representatives from the following organizations:  
 
Chief Government Chemist Laboratory Agency (CGCLA)  
Kisinga Youth and Women Foundation Centre (KYWFC)  
Ministry of Health (MOH)  
SUMAIT University  
Tanzania Bureau of Standards (TBS)  
Zanzibar Environment Management Authority (ZEMA)  
Zanzibar Food and Drugs Agency (ZFDA)  
Zanzibar University (ZU)  
Zanzibar Bureau of Standards (ZBS) - Secretariat  
 
 
 
 
 
Zanzibar Bureau of Standards (ZBS)  
PO Box 1136  
Zanzibar  
Tel:  +255 24 2232225  
Fax: +255 24 2232225  
E-mail: info@zbs.go.tz  
Web: www.zbs.go.tz  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 PCD 506: 2023  
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Introduction  
 
Henna, Lawsonia Inermis  Linn has been known as natural source of dye having medicinal properties. 
After dilution with water, henna powder is used as paste for skin decorations, tattooing and hair dying. 
Upon drying, the paste imparts orange, dark red to very deep red  that appears almost black on skin 
while only typical reddish orange colour is imparted on white hair. In order to offer the convenience of 
ready to use paste to users, henna paste is supplied in different packaging like cones, tubes etc.  
 
Many commercial henna paste products available in the market lose their staining power on storage 
especially ones packed in cones. Destabilized paste of henna cones when used does not give any 
colouration. To increase the staining power and market value, some products are  sold with chemical 
dyes and pigments like p-phenylenediamine, basic and acidic dyes etc. which are potential allergens 
when used on skin. Such chemicals are not permitted in manufacture of henna paste.  
 
The pH and water quality used in manufacture of henn a paste play an important role in its stability and 
colour impartation.  
 
In reporting the results of the tests made in accordance with this Zanzibar National Standard, if the 
final value, observed or calculated is to be rounded off, it shall be done in acc ordance with ZNS 94.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 PCD 506: 2023  
1                                                                                                             ©ZBS 2023  - All rights reserved   
  
Henna Paste  — Specification  
 
1 Scope  
 
This draft Zanzibar National S tandard specifies  the requirements , sampling and test methods for 
ready -made henna paste in shape of cone and other allied packaging.  
 
2 Normative references  
 
The following referenced documents are indispensable for the application of this document. For dated 
references, only the edition cited applies. For undated referenc es, the latest edition of the referenced 
document (including any amendments) applies.  
 
    EAS 377 (all parts), Cosmetics and cosmetic products   
EAS 847 -16, Cosmetics —Analytical methods —Part 16: Determination of lead, mercury and arsenic 
content  
ISO 16212, Cosmetics —Microbiology —Enumeration of yeast and mould  
ISO 18416, Cosmetics —Microbiology —Detection of Candida albicans  
ISO 21149, Cosmetics --Microbiology --Enumeration and detection of aerobic mesophilic bacteria   
ISO 21150,  Cosmetics —Microbiology —Detection of Escherichia coli  
ISO 22716, Cosmetics — Good Manufacturing Practices (GMP) — Guidelines on Good 
Manufacturing Practices  
ISO 22717, Cosmetics —Microbiology —Detection of Pseudomonas aeruginosa  
ISO 22718, Cosmetics —Microbiology —Detection of Staphylococcus aureus  
ZNS 141 , Labelling of cosmetics  — General requirements  
ZNS 367, Cosmetics and toiletries products — Methods of sampling  
 
3 Terms and definitions  
For the purposes of this document , the (term s and) definition s given in EAS 846 and the following  shall 
apply.  
 
3.1  
henna paste  
a homogeneous mixture prepared by mixing natural henna powder with water to imparts colour stains 
on skin or hair.  
 
3.2  
p-phenylenediamine  
chemical  added to the natural henna to obtain  dark brown color instead of the orange / reddish color 
that natural henna gives and also speeds up the decorating process  
 PCD 506: 2023  
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4 Requirement s 
 
4.1 General  requirements  
 
4.1.1  All ingredients used in the manufacture of henna paste shall comply with all parts of EAS 377.  
4.1.2  The henna paste shall be free from extraneous adulterants. These include stems, small fruits, 
husk of paddy, leaves and twigs of other shrubs.  
4.1.3  The henna paste  shall be smooth and free from  lumps or particles.  
4.1.4  The henna paste may be added s mall quantities of essential oils, binding agents, suitable 
preservatives and other auxiliary excipients necessary to impart cosmetic and functional 
properties to form a smoot h and stable paste.  
4.1.5  The product shall be produced, prepared and handled in accordance with ISO  22716.  
 
4.2 Specific requirements  
 
4.2.1  Henna paste shall comply with the specific requirements given in Table 1 when tested in 
accordance with the test methods specified  therein.  
  
Table 1: Specific requirements for henna paste  
S/No.  Characteristic  Requirement  Test method  
i.  pH of 5 percent aqueous suspension  3 - 6 Annex A  
ii.  Loss on drying, % by mass , max. 80 Annex B  
iii.  Lawsone content in paste form, % by mass , min. 0.25 Annex C   
iv.  Absence of chemical dyes and pigments  To pass the test  Annex D  
 
 
4.2.2  Henna paste  shall comply with the limits for heavy metal contaminants given in Table 2 when 
tested in accordance with the test methods specified therein.  
 
 
Table 2: Heavy metal contaminant limits for henna paste  
 
S/NO  Heavy metal  Maximum limit a 
mg/kg  Test method  
i) Lead (as Pb)  10.0  
EAS 847 -16 
ii) Arsenic (as As)  2.0 
iii) Mercury (as Hg)  2.0 
 
aThe total amount of heavy metals as lead, mercury and arsenic, in combination in the finished product shall not 
exceed 10 mg/kg.  
 
 
 
 
 
 
 
 
 
 
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3                                                                                                               ©ZBS 202 3- All rights  reserved  4.2.3  Henna paste  shall comply with the microbiological limits given in Table 3 when tested in 
accordance with the test methods specified therein.  
 
Table 4: Microbiological limits for henna paste  
 
S/NO  Microorganism  Limit  Test method  
i.  Total viable count for aerobic mesophyllic micro - 
organisms, CFU/g or CFU/ml, max.  100 ISO 21149  
ii.  Pseudomonas aeruginosa   
 
Not detectable in 1 g of 
cosmetic product  ISO 22717  
iii.  Staphylococcus aureus  ISO 22718  
iv.  Candida albicans  ISO 18416  
v.  Escherichia coli  ISO 21150  
vi.  Yeast and mould, CFU/g , max.  100 ISO 16212  
 
5 Packaging  
The henna paste shall be packed in suitable containers like films drawn into a cone or any other 
suitable pack aging to protect the contents and shall not cause any contamination or react with the 
product .  
 
When packed in containers, the containers shall be properly sealed and have a leak -proof cap or 
closure. The containers, if necessary, may further be packed in cartons or any other suitable 
packaging material.  
 
6 Labe ling 
In addition to the label ing requirements given in ZNS 141 , the package shall be legibly and indelibly 
marked with the following:  
 
a) product name as ‘Henna paste ’; 
b) cautions  ‘DO NOT  USE FOR  COLOURING  EYELASHES OR EYEBROWS. DO NOT USE  
ON CUT, IRRITATED OR SCRATCHED  SKIN’ ; and  
c) storage conditions as ‘ Store away from heat and direct sunlight ’. 
 
7 Sampling  
Sampling shall be done in accordance with ZNS 367 . 
 
 
 
 
 
 
 
 
 
 
 
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 Annex A  
(Normative)  
Determination of pH  
 
 
A.1  Apparatus  
 
A.1.1  pH Meter  — Preferably equipped with glass electrode.  
  
A.2 Procedure  
Weigh accurately about 5 g of henna paste in 250 ml beaker. Add 100 ml water;  stir for 5 min. 
Determine the pH of suspension at 27 ± 2°C using the pH meter.  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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5                                                                                                               ©ZBS 202 3- All rights  reserved  Annex B  
(Normative)  
Determination of l oss on drying  
 
B.1 Outline of the method  
This method determines loss on drying which the loss in weight, percent (w/w) is resulting from water 
and volatile matter of any kind that can be driven off under specified conditions. The test is carried out 
on a well - mixed sample of the henna paste.  
 
B.2 Apparatus  
B.2.1 Drying Oven  
 
B.3 Procedure  
B.3.1 Weig h a glass stoppered, shallow weighing bottle that has been previously dried at 105 ± 2°C to 
constant weight and cool in desiccators. Note down the weight (W 1). 
B.3.2 Transfer 1 g of sample to the bottle, cover it and accurately weigh th e bottle and the con tents. 
Note down the weight (W 2). Distribute the sample as evenly as practicable by gentle sidewise shaking 
to a depth not exceeding 10 mm.  
B.3.3 Place the loaded bottle in the drying oven/ desiccators, remove the stopper and keep it also in 
the drying oven/desiccators.  
B.3.4 Dry the sample at 105 ± 2°C to constant weight. After drying is completed, open the drying 
chamber, close the bottle promptl y and allow it to cool to room temperature (where applicable) in a 
desiccator  before weighing. Weigh the bottle and the contents (W 3). 
 
Loss on drying, percent =   Loss in weight x 100  
                                         Weight of sample taken  
 
                                          = W2 - W3 x100 
                                              W2 - W1 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 Annex C  
(Normative)  
Determination of Lawsone content by Colorimetry  
 
C.1 Outline of method  
The pigment is extracted and the Lawson  content is determined by comparing the observed optical 
density (measured colorimetrically) with a calibration curve, relating optical density to various 
concentrates of 2 -hydroxy -1,4-napthoquinone.  
  
C.2 Apparatus  
C.2.1 Spectrophotometer or Photoelectric Colorimeter  (with a filter of 490 nm)  
 
C.3 Reagents  
C.3.1 Sodium b icarbonate Solution  — 5 % (m/v).  
C.3.2 2 Hydroxy -1,4-napthoquinone   
 
C.4 Procedure  for p reparation of Standard Calibration Curve  
 
C.4.1  Construct a calibration curve by dissolving known amounts of 2 -hydroxy -1,4-naphthoquinone 
(C10H6O3) varying in concentration from 0 % to 2 % under the same condition as described in C.4.2 
below.  
  
C.4.2 Weigh accurately, 2.0 g of the dry henna paste (or we t paste equivalent to 2 g on dry basis) 
prepared sample. Transfer it to a 100 ml volumetric flask. Add sodium bicarbonate solution [5 percent, 
(m/v)] and make up the volume to mark. Shake the contents of the flask every half an hour or so for 
about 8 h. Al low to settle overnight. Thereafter filter the solution through a filter paper and reject the 
first few milliliters. Take 10 ml of the filtrate in a 25 ml volumetric flask and dilute with distilled water  up 
to the mark. Measure the optical density of this solution with a spectrophotometer at 490 nm.  
 
C.5 Calculation  
Refer to the calibration c urve and determine the percent l awsone content of the sample from the 
curve.  
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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7                                                                                                               ©ZBS 202 3- All rights  reserved  Annex D 
(Normative)  
Determination of absence of chemical dyes and pigments by TLC  
 
D.1 Outline of the method  
To detect contamination of chemical dyes or synthetic pigments if any, the Thin Layer  
Chromatography (TLC) method shall be used.  
 
D.2 Apparatus  
D.2.1 Weighing Balance  
D.2.2 TLC Plates  — Precoated silica gel 60 F 0.2 mm thickness  
D.2.3 TLC Apparatus / Beakers  — 250 ml (narrow)  
D.2.4 Iodine Chamber  
D.2.5 Test Tubes, with stoppers   
D.2.6 Volumetric Flask , 10 ml   
D.2.7 Micro Syringe , 10µl  
D.2.8 Silicone Wax  
 
D.3 Reagents  and standards  
D.3.1 Chloroform   
D.3.2 Methanol  
D.3.3 Glacial Acetic Acid   
D.3.4 Ethyl Acetate  
D.3.5 Iodine Granules  
D.3.6 Standards —   Pure   henna, lawsone  pigment , chemical/synthetic dye ingredients1 like   
p-phenylenediamine, p-aminophenol, m -aminophenol, 2 -nitro-p-phenyleneamine, etc.  
D.3.7 Essential Oils  — Clove oil,  terpineol oil, eucalyptus oil, tea tree oil, lemon oil or any other 
essential oils declared on the label matter by the manufacturer.  
D.3.8 Preservatives — Benzyl  alcohol or any other preservative declared on the label matter by the 
manufacturer.  
D.3.9 Test Sample  — 1 g of henna paste sample being tested.  
 
D.4 Preparation  of solution   
D.4.1 Mobile Phase  
Chloroform:  ethyl acetate:  methanol:  glacial acetic acid (8:2:1:1 v/v). Take the solvents chloroform, 
ethyl acetate, methanol and glacial acetic acid in 8:2:1:1 v/v, mix well and keep stoppered.  
 
D.4.2 Sample Solutions  
Dissolve about 1 g of test sample with chloroform into the 10 ml flask an d make up volume to ml with 
chloroform then centrifuge at 4 000 rpm for about 10 min and use the supernatant liquid for spotting.  
 
D.4.3 Reference Solutions  
Weigh about 50 mg ± 1 mg of the reference substance in 10 ml flask. Dissolve and dilute to 10 ml wi th 
chloroform. Prepare 0.5 percent (w/w) solution of each reference substances lawsone, clove oil, 
eucalyptus oil and terpineol separately. Additionally, if required, p -phenylenediamine, p -aminophenol, 
m-aminophenol, 2 -nitro-p-phenyleneamine, or any other suspected dyes separately.  
 
D.4.4 Preparation of Henna Powder Reference Sample  
Disperse about 3 g of henna powder prepared from authentic henna leaves in water and make a 
 
1 To be used if unknown spots are seen on the sample plates.  PCD 506: 2023  
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 smooth paste, allow to stand for 4 h. Mix 1 g of this paste with chloroform into the 10 ml flask and 
make up volume to 10 ml with chloroform then centrifuge at 4 000 rpm for about 10 min and use the 
supernatant liquid for spotting and apply one drop of the extract on the base line of the plate  
 
D.5 Procedure  
D.5.1 Pour 15 -20 ml of mobile phase into the 250 ml narrow beaker (developing chamber) and cover 
with a suitable petri dish using silicone wax as a sealant.  
D.5.2 Apply to a chromatography plate, about 5 µl of each of above described reference solutions and 
sample solution along a line approximately 1.5 cm from the edge of the plate.  
D.5.3 Place the plate in a tank previously saturated with the development  solvents and allows to 
develop at room temperature in the tank until the solvent front moved about 80 perce nt of plate height.  
D.5.4 Remove the TLC plate, allow the plate to dry completely and place a plate in iodine chamber to 
develop the chromatogram.  
 
D.6 Identification  
D.6.1 Compare the Rf value and the color obtained from the sample with those of the reference 
substances chromatog raphed and identify spots. Compare the TLC pattern of the sample with that of 
the lawsone reference sample and standard henna paste Sample using henna powder reference 
sample which is prepared from authentic henna leaves.  
D.6.2 Any other dye spots on the chromatogram other than lawsone, binding agents, essential oils and 
chlorophyll indicates presence possible extraneous dyes. In case, unknown spots from suspected 
chemical dyes are observed, further testing is done by applying t he standards of suspected synthetic 
dyes and check for matching Rf values and spot characteristics.  
 
Representative elution order of above samples with some commonly used synthetic adulterants 
(lowest Rf to highest Rf) — p-aminophenol, m -aminophenol,  2-nitro-p-phenyleneamine, lawsone, 
chlorophyll .  
D.6.3 Confirmation of doubtful identification may sometimes be achieved by a spiking method, adding 
the corresponding reference substance solution to the sample extract. Or if sample shows additional 
spots, confirmation is to be done by scraping the spot and conducting the UV or IR spectrum.  
NOTES:  
1. Since the henna is a natural product, TLC pattern may slightly vary depending upon the change 
in weather conditions, age of plant, season and different agro - climatic locations. Hence, if other 
spots are observed in addition to the spots due to chlorophyll and lawsone this needs to be 
reconfirmed with TLC pattern of henna . Confirmatory may be necessary to conclude the presence 
of extraneous dyes. This may be done  by scraping out the respective spot and solubilizing and 
checking using other analytical methods like Spectrophotometric, HPLC etc.  
2. If the concentration of one or more of the substances found in the sample is excessive, dilute 
the sample extract and re peat the test.  
3. A reddish orange spot due to lawsone will elute, and the greenish spot due to chlorophyll will be 
coincident with liquid front. Other spots due to the addition of essential oils may also be seen. 
These spots may interfere with the chemica l/synthetic dye ingredients/pigments present in the 
sample if any. In such case alternative validated chromatographic conditions are acceptable in 
order to improve/achieve clear separation, or reproducibility. Responsibility of changes in 
chromatographic c onditions lies with manufacturer.  
 
 PCD 506: 2023  
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