DEAS 933: 2018
ICS 55.120
 
© EAC 2018                                                                                                                              First Edition 2018 
 DRAFT EAST AFRICAN STANDARD 
Paper and board intended to come int o contact with foodstuffs —
Determination of formalde hyde in an aqueous extract 
EAST AFRICAN COMMUNITY DEAS 933: 2018 
© EAC 2018 – All rights reserved ii
 Copyright notice 
This EAC document is copyright-protected by EAC. While the repr oduction of this document by 
participants in the EAC standards development process is permit ted without prior permission from EAC, 
neither this document nor any extract from it may be reproduced , stored or transmitted in any form for 
any other purpose without prior written permission from EAC. 
Requests for permission to reproduce this document for the purp ose of selling it should be addressed 
as shown below or to EAC’s mem ber body in the country of the re quester: 
© East African Community201 8 — All rights reserved 
East African Community 
P.O.Box 1096, 
Arusha 
Tanzania 
Tel: + 255 27 2162100 
Fax: + 255 27 2162190 
E-mail: eac@eachq.org   
Web: www.eac-quality.net   
Reproduction for sales purposes may be subject to royalty payme nts or a licensing agreement. 
Violators may be prosecuted. DEAS 933: 2018 
© EAC 2018 – All rights reserved  iii
 Foreword 
Development of the East African Standards has been necessitated  by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade barriers that are encountered  when goods and services are exchanged 
within the Community will be removed.  
The Community has established an East African Standards Committ ee (EASC) mandated to develop and 
issue East African Standards (EAS).The Committee is composed of  representatives of the National Standards 
Bodies in Partner States, together with the representatives fro m the public and private sector organizations in 
the community.  
East African Standards are developed through Technical Committe es that are representative of key 
stakeholders including government, academia, consumer groups, p rivate sector and other interested parties. 
Draft East African Standards are circulated to stakeholders thr ough the National Standards Bodies in the 
Partner States. The comments received are discussed and incorpo rated before finalization of standards, in 
accordance with the Principles and procedures for development o f East African Standards.  
East African Standards are subject to review, to keep pace with  technological advances. Users of the East 
African Standards are therefore expected to ensure that they al ways have the latest versions of the standards 
they are implementing .  
The committee responsible for this document is Technical Commit tee EASC/TC 066, Packaging . 
Attention is drawn to the possibility that some of the elements  of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any o r all such patent rights. 
During the preparation of this Standard, reference was made to the following document: 
EN 1541, Paper and board intended to come into contact with foodstuffs — Determination of formaldehyde in 
an aqueous extract  
Acknowledgment is hereby made for the assistance derived from t his source. 
 DRAFT EAST AFRICAN S TANDARD DEAS 933: 2018
 
© EAC 2018 – All rights reserved 1
 Paper and board intended to come  into contact with foodstuffs 
— Determination of formaldeh yde in an aqueous extract 
1 Scope 
This Draft East African Standard specifies the determination of  formaldehyde in aqueous extracts prepared 
from paper and board intended to  come in contact with foodstuff s. The limit of determination is 1 mg/kg. 
2 Normative references 
The following documents are referred to in the text in such a w ay that some or all of their content constitutes 
requirements of this document. For dated references, only the e dition cited applies. For undated references, 
the latest edition of the refer enced document (including any am endments) applies. 
ISO 6588-1, Paper, board and pulps — Determination of pH of aqueous extracts — Part 1: Cold extraction  
ISO 6588-2, Paper, board and pulps — Determination of pH of aqueous extracts — Part 2: Hot extraction  
3 Terms and definitions 
For the purposes of this standar d, the following terms and defi nitions apply. 
3.1 
cold water extract water solution obtained as a result of cold extraction ISO 6588 -1 
3.2 
hot water extract water solution obtained as a result of hot extraction ISO 6588- 1 
4 Principle 
Formaldehyde reacts with pentane-2, 4-dione (acetyl acetone) in  the presence of ammonium acetate to form 
3, 5-diacetyl-1, 4-dihydrolutidine. The absorbance of the extra ct is measured at a wavelength of 410 nm. 
NOTE The extract should also be scanned by ultraviolet (UV) spe ctroscopy for confirmation where the level of 
formaldehyde exceeds specified limits (see clause 10). 
5 Reagents 
All reagents shall be of analytical grade and the water shall b e distilled or of equivalent purity. 
5.1 Anhydrous ammonium acetate 
5.2 Acetic acid 99 % (d = 1.05)  
5.3 Pentane-2.4-dione 5.4 Hydrochloric acid, 1 mol/l  
5.5 Sodium hydroxide solution, 1 mol/l   
2 © EAC2018 – All rights reserved
 5.6 Starch solution freshly prepared, 2 g/l 
5.7 Formaldehyde solution, 370 g/l to 400 g/l  
5.8 Standard iodine solution , 0.05 mol/l  
5.9 Standard sodium thi osulphate solution, 0.1 mol/l  
5.10 Pentane-2, 4-dione reagent 
In a 100.0-ml volumetric flask dissolve: 
a) 15.0 g anhydrous ammonium acetate (see 5.1); 
b) 0.2 ml pentane-2, 4-dione (see 5.3); 
c) 0.3 ml acetic acid (see 5.2); d) 25 ml of water. 
Make up to 100.0 ml with water. This reagent shall be freshly p repared. 
5.11 Reagent  (see 5.10) without pentane-2, 4-dione 
5.12 Formaldehyde-standard: Stock solution 
5.12.1  Measure 5.0 ml formaldehyde solution (see 5.7) into a 1000 ml volumetric flask and make up to 1000 
ml with water. 
5.12.2 Just before use determine the concentration of this solution as  follows. 
Transfer 10.0 ml of the stock solution into a conical flask, ad d 25.0 ml of a standard iodine solution (see 5.8) 
and 10.0 ml of sodium hydroxide solution (see 5.5). Allow to st and for 5 min. Acidify with 11.0 ml of 
hydrochloric acid (see 5.4) and determine the excess iodine by titration with a standard sodium thiosulphate 
solution (see 5.9), using 0.1 ml  of the starch solution (see 5. 6) as indicator. 
NOTE Add the starch solution when the solution being titrated h as become a pale straw colour. Theoretically, 1.0 ml 
of 0.05 mol/l iodine consumed is equivalent to 1.5 mg formaldeh yde. 
5.13 Formaldehyde-standard: Dilute solution 
Dilute an aliquot of the formaldehyde stock solution (see 5.12)  to 20 times its volume with water, and then 
furtherdilute an aliquot of this second solution to 100 times i ts volume so that 1.0 ml of the final solution 
contains about 0.001 mg of formaldehyde. Use pipettes and volum etric flasks. Calculate the actual 
formaldehyde content. This solution shall be freshly prepared. 
6 Apparatus 
6.1 Ordinary laboratory apparatus  
6.2 Spectrophotometer for use at the wavelength of 410 nm , with cells of an optical path length of 10 
mm. 
6.3 Scanning ultraviolet (UV) spectrophotometer in the range of 30 0 nm to 500 nm (Only for the 
confirmation steps). 
6.4 Thermostatic water-bath capable of maintaini ng a temperature of  (60 °C ± 2 °C).  
© EAC 2018 – All rights reserved  3
 7 Preparation of sample 
Sampling, sample preparation and extraction shall be carried ou t according to the methods for the preparation 
of cold water (ISO 6588-1) or hot water extracts (ISO 6588-2).T wo parallel extractions shall be carried out. 
The test shall be performed not longer than 24 h after extracti on. 
8 Procedure 
8.1 For each extract at least two parallel determinations shall  be carried out 
Att room temperature the cold water extract is applied while fo r paper and board materials intended for boiling 
and hot filtering purposes the hot water extract is applied 
8.2 Sample solution 
Into a 50-ml conical flask add: 
- 25.0 ml extract (V1) (see 8.1); 
- 5.0 ml pentane-2.4-dione reagent (see 5.10). 
8.3 Reference solution 
Possible interference due to coloured substances in the aqueous  extract is eliminated by the use of this 
reference solution. 
Into a 50-ml conical flask add 
- 25.0 ml extract (see 8.1); 
- 5.0 ml reagent without penta ne - 2.4-dione (see 5.11). 
8.4 Blank test 
This is performed in order to con struct the calibration curve. 
Into a 50-ml conical flask add 
- 25.0 ml water; - 5.0 ml pentane - 2.4-d ione reagent (see 5.10). 
8.5 Determination 
8.5.1 Shake the solutions 8.2, 8.3 and 8.4 for about 15 s. Immerse th e conical flasks in a thermostatic 
waterbath (see 6.4) at (60 °C ± 2°C) for 10 min ± 10 s. Allow t o cool for at least 2 min in a bath of iced water. 
8.5.2  Bring the solutions into the measuring cells (see 6.2). Measur e the absorbance at 410 nm of the 
sample solution (see 8.2) with the reference solution (see 8.3)  in the reference cell (A1). 
8.5.3  Measure the absorbance of the blank test (see 8.4) with water in the reference cell (A2). 
8.5.4  The absorbance measurements shall be made between 35 min and 6 0 min from the time when the 
conical flasks were placed in the water bath at 60 °C.  
4 © EAC2018 – All rights reserved
 8.5.5  If the value of formaldehyde obtained exceeds the range covere d by the calibration solutions, the 
measurement shall be repeated with a more dilute sample solutio n and using an equally diluted reference 
solution. 
8.6 Calibration curve 
8.6.1 Into a 50-ml conical flask add: 
- 1.0 ml of the formaldehyde diluted standard solution (see 5.1 3); 
- 5.0 ml of the pentane – 2. 4-dione reagent (see 5.10); 
- make up with water to 30.0 ml. 
8.6.2 Continue as described in 8.5 and measure the absorbance with wa ter (see 8.5) in the reference cell. 
8.6.3 Repeat the procedure with 5.0 ml; 10.0 ml; 15.0 ml; 20.0 ml and  25.0 ml of the formaldehyde diluted 
standard solution (see 5.13).Construct the calibration curve af ter subtraction of the blank test value (see 8.5) 
from each of the absorbance obtained. 
9 Calculation and expression of results 
9.1 Subtract A2 from A1 and read off from the calibration curve (s ee 8.6) the amount C in mg of 
formaldehyde in the sample solution (see 8.2). 
9.2 Calculate the formaldehyde conte nt of the sample (Cs ) or (Cm ) as follows: 
C2-C x௏଴
௏ଵ x ௕
ଵ଴଴ x ଵ
ீ 1 
Cm-C x௏଴
௏ଵx ଵ
ீ x ଵ଴଴
ଵ଴଴ି௙ x 100 2 
where, 
Cs amount of formaldehyde soluble of the sample in mg/dm²; 
Cm amount of formaldehyde soluble of the sample in mg/kg; 
C amount of formaldehyde read from the calibration graph, in mg ; 
V0 otal volume of extract (250 ml), in ml; 
V1 volume taken for the  test (25.0 ml), in ml; 
B grammage, in g/m²; G mass, in grams, of the sample ta ken under the same condition as grammage; 
F moisture content of the sample, in %. 
Report the result with two significant figures. 
10 Confirmation 
10.1 Requirement for confirmation 
Where the level of formaldehyde in the water extract under test  (see clause 7) exceeds any specified limit, the 
determination shall be confirmed by scanning ultraviolet (UV) s pectroscopy (see 6.3).  
© EAC 2018 – All rights reserved  5
 10.2 Standard spectrum 
Whilst preparing the formaldehyde derivative (see 8.5), scan th e intermediate standard (10.0 ml standard from 
8.6) from 300 nm to 500 nm. Record the position and absorbance value at the peak maximum and calculate 
the ratio of the measurements of the absorbance measured at 20 nm increments either side of the maximum. 
The spectrum shall satisfy the following conditions: 
a) the maximum shall be in the range from 408 nm to 411 nm; b) the spectrum shall tend to zero absorbance, that is less tha n 0.02 absorbance units, below 320 nm. 
Examples of the absorbance ratios to be expected are listed in Table 1. 
Maximum absorbance: 410 nm 
Table 1 — Examples of absorbance ratios at corresponding wavele ngths 
Wavelength pair in nm Ratio
370 / 410 0.520 ± 0.02 
390 / 410 0.843 ± 0.01 
430 / 410 0.802 ± 0.01 
450 / 410 0.386 ± 0.02 
 
12 Test report 
The test report shall refer to this East African Standard and s tate: 
a) extraction method; 
b) nature, origin and designation of the sample; 
c) date of sampling; d) date of test; 
e) mean result; 
f) whether confirmation test has been carried out and if so, it s result; 
g) any deviations from this East African Standard.  
6 © EAC2018 – All rights reserved
 Bibliography 
Kenyan std 
 
 
 DEAS 933: 2018 
 
© EAC 2018 – All rights reserved