ISO/R 1908:1971

Ref. No. :ISO/R 1908-1971 (E)
UüC hhl : 547.562i563
IS0
I NT ERN AT1 ON A L O RG AN IZATl ON FOR STA N DA RD1 ZATl ON
IS0 RECO M MEN DATI O N
R 1908
CRESYLIC ACID AND XYLENOLS
FOR INDUSTRIAL USE
TEST FOR ABSENCE OF HYDROGEN SULPHIDE
1st EDITION
May 1971
COPYRIGHT RESERVED
The copyright of IS0 Recommendations and IS0 Standards
belongs to IS0 Member Bodies. Reproduction of these
documents, in any country, may be authorized therefore only
by the national standards organization of that country, being
a member of ISO.
For each individual country the only valid standard is the national standard of that country.
Printed in Switzerland
Also issued in French and Russian. Copies to be obtained through the national standards organizations.

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BRIEF HISTORY
The IS0 Recommendation R 1908, Cresylic acid and xylenols for industrial use - Test,for absence of hydrogen
sulphide, was drawn up by Technical Committee ISO/TC 47, Chemistry, the Secretariat of which is held by the Ente
Nazionale Italiano di Unificazione (UNI).
Work on this question led to the adoption of Draft IS0 Recommendation No. 1908, which was circulated to all
the IS0 Member Bodies for enquiry in November 1969. It was approved, subject to a few modifications of an editorial
nature. by the following Member Bodies :
Australia Israel Spain
Belgium Italy Switzerland
Chile Japan Thailand
Czechoslovakia
Netherlands Turkey
France
New Zealand U.A.R.
Germany
Poland United Kingdom
Greece Portugal
U. S. S. R .
Hungary Romania
India South Africa, Rep. of
No Member Body opposed the approval of the Draft.
This Draft IS0 Recommendation was then submitted by correspondence to the IS0 Council, which decided to
accept it as an IS0 RECOMMENDATION.

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IS0 Recommendation R 1908 May 1971
CRESYLIC ACID AND XYLENOLS
FOR INDUSTRIAL USE
TEST FOR ABSENCE OF HYDROGEN SULPHIDE
c
WARNING. These materials burn the skin and can be absorbed into the system through the skin. It is essential for
the sampler to wear protective gloves, for example of polyvinyl chloride, and also a face shield. Inhalation of the
vapours from hot material is to be avoided.
1. SCOPE AND FIELD OF APPLICATION
This IS0 Recommendation describes a method of testing for the absence of hydrogen sulphide and is applicable
to cresylic acid of high rn-cresol content, cresylic acid of high o-cresol content and xylenols, for industrial use.
NOTE. - This is a simple qualitative test for the absence of hydrogen sulphide and is in no way quantitative.
i
2. SAMPLING
Apply the principles given in IS0 Recommendation , . .*. The following principles should also be observed :
Place the laboratory sample representative of the material taken from the bulk in a clean, dry, dark-coloured, glass-
stoppered bottle of such a size that it is nearly filled by the sample. if it is necessary to seal this bottle, care should
be taken to avoid contaminating the contents.
3. PRINCIPLE
Formation of a brown colour on lead acetate paper due to reaction with any hydrogen sulphide present.
*
Sampüng of chemical products will form the subject of a future IS0 Recommendation.

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4. REAGENT
Distilled water or water of equivalent purity sho
...