ICS 71.100.70  
 
Reference number
DRS 489-4:2023
© RSB2023
  
 RWANDA 
STANDARD  DRS 
489-4 
 
Second edition  
2023-mm-dd  
 
Oils for cosmetic use—Specification  
Part 4: Castor oil  
   
Formatted:  English (United States)DRS 489-4:2023 
©RSB 2023- 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 
 
 
 
 
 
 
 
 
© RSB2023 
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 RSB. 
Requests for permission to reproduce 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  Formatted:  French (France)
Field Code Changed
Formatted:  English (United Kingdom)
Formatted:  French (France)DRS 489-4: 2023 
iii                ©RSB2023- All rights reserved 
 Contents Page 
Foreword ............................................................................................................................................................ iv  
 
1 Scope ...................................................................................................................................................... 1  
2 Normative references ............................................................................................................................ 1  
3 Terms and definitions ........................................................................................................................... 2  
4 Requirements ......................................................................................................................................... 2  
4.1 General requirements ........................................................................................................................... 2  
5 Packaging ............................................................................................................................................... 3  
6 Labelling ............................................................................................................................................... 43 
7 Sampling .............................................................................................................................................. 43 
Annex A (normative)  Method for detection of the processing (cold pressed or hot pressed) of 
castor oil ............................................................................................................................................... 54 
A.1 General ................................................................................................................................................. 54 
A.2 Apparatus ............................................................................................................................................. 65 
A.3 Reagents .............................................................................................................................................. 65 
A.4 Preparation ........................................................................................................................................... 76 
A.5 Procedure ............................................................................................................................................. 76 
Annex B (normative)  Determination of critical solution temperature ........................................................ 98 
B.1 Reagent ................................................................................................................................................ 98 
B.2 Procedure ............................................................................................................................................. 98 
 
 DRS 489-4:2023 
©RSB 2023- All rights reserved                  iv 
 Foreword 
Rwanda Standardsarepreparedby Technical Committees and approved by Rwanda 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 a+pplication of standards. 
The main task of technical committees is to prepare national standards. Final Draft Rwanda Standards 
adopted by Technical committees are ratified by members of RSB Board of Directors for publication and 
gazettment as Rwanda Standards. 
DRS489-4 was prepared by Technical Committee RSB/TC 011, Cosmetics and related products.  
DRS 489 consists of the following parts, under the general title Oils for cosmetic use — Specification : 
— Part 1:  Baobab seed oil  
 
— Part 2:  Chia seeds oil 
 
— Part 3: Passion fruits (maracuja) seed oil  
 
— Part 5: Macadamia oil 
 
Committee membership  
The following organizations were represented on the Technical Committee on Cosmetics and related 
products (RSB/TC 011) in the preparation of this standard. 
University of Rwanda -College of Science and Technology (UR-CST) 
Rwanda Food and Drugs Authority (Rwanda-FDA) 
Rwanda Inspectorate, Competition and Consumer protection Authority (RICA) 
Rwanda Forensic Laboratory (RFL) 
Kipharma 
SULFO Industries Rwanda 
ORIBUT Company Ltd 
Uburanga products DRS 489-4: 2023 
v                ©RSB2023- All rights reserved 
 Rwanda Medical Supply (RMS) 
Rwanda Standards Board(RSB) – Secretariat DRS 489-4:2023 
©RSB 2023- All rights reserved                  vi 
 Introduction 
Oils and fats are among the most important cosmetic ingredients and are frequently used for a variety of 
external applications. They can be used directly as skin and hair care products but also as the basic 
substances for the manufacture of cosmetic products. Many of the cosmetic and hair care products on the 
market today rely on hydrocarbon molecules, derived from either mineral or vegetable oils, to provide 
antistatic, plasticiser and viscosity properties. Vegetable oils made from almonds, castor, coconut and palm oil 
consist of ethereal salts of glycerine plus a large number of organic acids forming stearin, olein and 
palmitin,essential ingredients of these products. 
Castor oil and derivatives are used in soaps, creams (tretinoin), shampoos, perfumes, lip gels, lipsticks, hair 
oils (increases hair luster), deodorants, lubricants, sunscreens, and many other personal hygiene and beauty 
products. 
Castor oil has been used in skin care products for centuries and continues to play an important part in the 
production of soaps and cosmetics. Cosmetic manufacturers use castor oil and its derivatives in formulating 
non-comedogenic cosmetics (cosmetics that don't exacerbate or contribute to acne) and emollients. DRS 489-4: 2023 
1                ©RSB2023- All rights reserved 
 Oils for cosmetic use — Specification— Part 4: Castor oil 
1 Scope 
This Draft Rwanda Standard specifies the requirements, sampling and test methods for castor oil for cosmetic 
industry. 
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 editioncited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies. 
RS EAS 346, Labelling of cosmetics — General requirements  
RS EAS 846, Glossary of terms relating to the cosmetic industry 
RS EAS 847-2, Cosmetics — Analytical methods — Part 2: Determination of moisture content and 
volatilematter content 
RS EAS 847-5, Cosmetics — Analytical methods — Part 5: Determination of unsaponifiable matter  
RS EAS 847-7, Cosmetics — Analytical methods — Part 7: Determination of specific gravity 
RS EAS 847-9, Cosmetics — Analytical methods — Part 9: Determination of colour 
RS EAS 847-10, Cosmetics - Analytical methods - Part 10: Determination of acetyl value and hydroxyl value  
RS EAS 847-12, Cosmetics — Analytical methods — Part 12: Determination of flash point by Pensky —
Martens Closed Cap Tester 
RS EAS 847-13, Cosmetics — Analytical methods — Part 13: Determination of rancidity  
RS EAS 847-16 , Cosmetics — Analytical methods — Part 16: Determination of lead, mercury and 
arseniccontent 
RS ISO 660, Animal and vegetable fats and oils — Determination of acid value and acidity 
RS ISO 663, Animal and vegetable fats and oils — Determination of insoluble impurities content  
RS ISO 3657, Animal and vegetable fats and oils — Determination of saponification value  
RS ISO 3961, Animal and vegetable fats and oils — Determination of iodine value   
©RSB 2023- All rights reserved                  2 
 RS ISO 6320, Animal and vegetable fats and oils — Determination of refractive index  
RS ISO 24153, Random sampling and randomisation procedures  
3 Terms and definitions 
For the purposes of this standard, terms and definitions given in RA EAS 846 and the following apply. 
3.1 
castor oil 
 
pure oil obtained from castor seeds ( Ricinus. Communis Linn., fan. Euphoribiaceae ) by a process of cold 
expression or solvent extraction using solvent hexane 
4 Requirements 
4.1 General requirements 
4.1.1 The product shall be castor oil obtained from high quality seeds Ricinus. Communis Linn., fan . 
Euphoribiaceae by a process of cold expression. The product shall further undergo bleaching withbleaching earth or 
activated carbon or both, and deodorization with steam. 
4.1.2 The product shall be practically odourless or have a very mild odour characteristic of castor oil. 
4.1.3 When examined visually, the product shall be clear and free from sediments and other foreign matter, 
separated water and added colouring and flavouring substances. 
4.1.4 Test for detection of cold pressed or hotpressed oilshall be cold pressed only as described in Annex A 
4.1.5 The product shall be free from admixture with other oils. 
4.2 Specific requirements 
4.2.1 The product shall comply with the requirements given in Table 1 when tested in accordance with the 
test methods specified therein  
Table 1— Specific requirements for castor oil for cosmetic industry 
S/N Characteristic Requirement Test method 
i. Moisture content, % m/m, max.  0.5 RS EAS 847-2  
ii. Insoluble impurities, % m/m, max.  0.25 RS ISO 663  
iii. Colour in a 1” cell on the Lovibond scale, 
expressed as Y + 5R, max. deepness  4.0 RS EAS 847-9  
iv. Refractive index at 20 ºC,  1.4770-1.4810 RS ISO 6320  
v. Specific gravity at 30/30 ºC,  0.954-0.960 RS EAS 847-7 Formatted:  French (France)
Formatted:  French (France)DRS 489-4: 2023 
3                ©RSB2023- All rights reserved 
  
 
 
 
 
 
4.2.2 Heavy metals limits 
The Product shall comply with the limits for heavy metal contaminants in accordance with Table 2 when tested 
in accordance with the test methods specified therein.  
Table 2— Limits of heavy metals contaminants for castor oil 
S/N Characteristics   Requirements 
mg/kg, max Test method 
i. Lead 10 
RS EAS 847-16  ii. Arsenic 2 
iii. Mercury 2 
NOTE1 The total amount of heavy metals as lead, mercury and arsenic, in combination, in the finished 
product should not exceed 10 mg/kg. 
NOTE 2 The heavy metals including lead, mercury and arsenic may be as a result of contamination during 
processing and should not be deliberately added as ingredients  
 
5 Packaging 
The product shall be packaged in suitable well-sealed containers that shall protect the contents and shall not cause 
any contamination or react with the products. vi. Saponification value, range  177-187 RS ISO 3657  
vii. Iodine value, range  82-90 RS ISO 3961  
viii. Acid value, max.  4.0 RS ISO 660  
ix. Unsaponifiable matter, % m/m, max.  1.0 RS EAS 847-5  
x. Acetyl value, min  143 RS EAS 847-10  
xi. Flash point, ºC (Pensky Martens closed), min.  127 RS EAS 847-12  
xii. Test for rancidity  Shall be free from rancidity  RS EAS 847-13  
xiii. Critical solution temperature,  ºC, max 0 Annex B  
©RSB 2023- All rights reserved                  4 
 6 Labelling 
6.1 In addition to the requirements of RS EAS 346, the Material Safety Data Sheet shall be provided.The 
product 
6.2 The phrase ‘For external use only’ shall be conspicuously marked (either printed on the label affixed to 
the container, or lithographed, or stenciled thereon with indelible ink). 
7 Sampling 
Sampling of the product shall be done in accordance with RS 278. DRS 489-4: 2023 
5                ©RSB2023- All rights reserved 
 Annex A 
(normative)  
 
Method for detection of the processing (cold pressed or hot pressed) of 
castor oil 
A.1 General 
The method involves the isolation of toxic components (Ricinine, etc.) from the castor oil by its treatment with 
acetone solution, followed by its extraction with chloroform. The chloroform extract is cleaned up, concentrated and 
spotted on TLC plates. The plates are developed at chamber saturation and excited under fluorescent light for 
visualization of the alkaloid(s). The hot pressed castor oil yields typical fluorescent spots in U.V. light (365 nm).  
©RSB 2023- All rights reserved                  6 
 A.2 Apparatus 
A.2.1 UV lamp, for fluorescent excitation in the long wave region (Chromato-Vue may be used with 
special advantage). 
A.2.2 Mechanical shaker/Magnetic stirrer  
A.2.3 TLC plates, (20 cm x 10 cm) and a suitable developing chamber  
A.2.4 A suitable spreading device, for adjusting layer thickness  
A.2.5 Conical flask, 300 mL to 500 mL  
A.2.6 Porcelain dishes, 50 mL 
A.2.7 Separating funnel, 500 mL 
A.2.8 Electric oven, with temperature control device  
A.2.9 Desicator, containing an efficient dryer  
A.2.10 Graduated micro-pipettes/Micro syringes  
A.3 Reagents 
A.3.1 Kieselegal ‘G’ or Equivalent grade silica gel, containing suitable amount of calcium 
sulphate as kinder (b). 
A.3.2 Whatman filter paper no. 42 (or equivalent).  
A.3.3 Anhydrous sodium sulphate.  
A.3.4 Acetone. 
A.3.5 Acetone: water (1:1, v/v).  
A.3.6 Chloroform.  
A.3.7 Methanol. 
A.3.8 Solvent system, chloroform:methanol (85:15, v/v). 
 DRS 489-4: 2023 
7                ©RSB2023- All rights reserved 
 A.4 Preparation 
The plates are coated with silica gel ‘G’ using a suitable spreading device, adjusting the layer thickness at 300 nm, 
allowed to set and activated at 115 ºC ± 1 ºC for an hour. The plates are stored in desiccators. 
 
A.5 Procedure 
A.5.1 The procedure shall be done as follows: 
a) take 10 mL of sample in a conical flask and add 50 mL acetone solution (B.3.5); 
b) heat the mixture on a boiling water bath till simmering starts; 
c) shake/stir the mixture using a mechanical shaker/magnetic stirrer for 15 minutes; 
d) let the mixture attain room temperature and the only layer float on the surface; 
e) filter through a water-soaked filter paper (no. 42); 
f) discontinue the filtration after the acetone extract stops trickling; 
g) transfer the filtrate into a separating funnel and extract with 5.3 mL of purified chloroform, shaking the 
mixture well each time; 
h) break the emulsion (if formed) by dropping a few crystals of anhydrous sodium sulphate; 
i) clean up both the portions of this extract by passing it slowing through a column containing suitable 
amounts of anhydrous sodium sulphate; 
j) receive the evaluate in a porcelain dish; 
k) evaporate the solvent on a boiling water bath and re-dissolve the residue in 0.2 mL dry chloroform; 
l) spot 0.05 mL on a silica gel coated plate (B.4); 
m) develop the plate at chamber saturation, using the above solvent system (B.3.8) till the solvent front 
reaches the height of 10 cm; and 
n) dry the plate using a blow-dryer and place it in an oven (maintained at 60 ºC to 80 ºC) for 5 minutes to 10  
©RSB 2023- All rights reserved                  8 
 A.5.2 Visualization of fluorescent spots, the plate is visualized under U.V. light in the long 
waveregion (365 μm). In case of hot pressed castor oil, two green fluorescent spot at Rf 0.5 and one deep blue 
spot at Rf 0.9 appear. A blue spot around Rf 0.7 may also appear sometimes. In case of cold pressed castor, oil 
bluespots Rf 0.9 and 0.7 may appear but the specific green spot shall be absent.  
A.5.3 Sensitivity, the method is highly sensitive in detecting the type of processing of castor oil. 
The genuine cold drawn (medicinal grade) castor oil, even after refining and bleaching, fails to pass 
the test. The method is also capable of detecting a mixture of as low as 5% to 10% of hot pressed 
castor oil with cold pressed castor oil. 
NOTE 1  Development at chamber saturation is recommended in order to achieve sharpness in resolution and 
improve the reproducibility of Rf values. 
NOTE 2 Solvent mixture should be prepared with care and as far as possible prepared freshly before each use. DRS 489-4: 2023 
9                ©RSB2023- All rights reserved 
 Annex B 
(normative)  
 
Determination of critical solution temperature 
B.1 Reagent  
The reagent shall be prepared by diluting ethyl alcohol or rectified spirit with distilled water till the 
relativedensity of the mixture at 15.5 ºC is 0.8303 ± 0.0001, when compared with distilled water at the 
sametemperature. De-natured alcohol shall not be used for this test. 
B.2 Procedure 
Mix in a test tube, 1.0 g of the oil, with 4.15 times its mass of the reagent. Upon examination, the solution thus 
obtained shall be perfectly clear at 20 ºC and shall remain clear when cooled and maintained for 5 minutes at 
a temperature of 0 ºC. 
 
  
©RSB 2023- All rights reserved                  10 
 Bibliography 
[1] RS 86:2018, Castor oil for cosmetic industry — Specification  
 DRS 489-4: 2023 
 
Price based on nnnpages 
©RSB2023- All rights reserved