This standard was last reviewed and confirmed in 2021. Therefore this version remains current.
The principle consists in decomposition of a test portion by Kjeldahl method, distillation of the ammonia liberated, determination of the nitrogen content by titration of the ammonia with sulfuric or hydrochloric acid, using phenolphthalein as indicator. The method is applicable to all types of leather in all types of tannage.
Buy this standard
|std 1 40|
|std 2 40||Paper|
A standard is reviewed every 5 years
Stage: 90.93 (Confirmed)
Got a question?
Check out our FAQs
+41 22 749 08 88
Monday to Friday - 09:00-12:00, 14:00-17:00 (UTC+1)
Keep up to date with ISO
Sign up to our newsletter for the latest news, views and product information.