NZQA registered unit standard
Title
Evaluate chrome tannage
Level
5
8399 version 7
Page 1 of 3
Credits
Purpose
8
This unit standard is for experienced people wishing to develop
their technical skills in leather manufacture.
People credited with this unit standard are able to: demonstrate
knowledge of chrome tanning agents; evaluate the mechanism
of chrome tannage; evaluate chrome tannage practices; and
evaluate chrome tanned leather chemical and physical
characteristics.
Classification
Fellmongery and Leather Processing > Leather Processing
Knowledge
Available grade
Achieved
Explanatory notes
None.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of chrome tanning agents.
Evidence requirements
1.1
Method of manufacture of a chrome tanning agent is described in terms of
reaction involved and production technique.
Range
1.2
Chemistry of a basic chrome sulphate tanning agent is described in terms of
characteristics relevant to tanning.
Range
1.3
evidence is required of sulphur dioxide reduction or glucose
reduction.
evidence is required of chrome complex form and one of –
chromium oxide content, basicity, masking.
Problems associated with the use of chrome tanning agents on woolskins are
described in terms of potential adverse effects on final product.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
8399 version 7
Page 2 of 3
Outcome 2
Evaluate the mechanism of chrome tannage.
Evidence requirements
2.1
Mechanism of chrome tannage is evaluated in terms of reagent penetration and
subsequent fixation to skin.
Range
evidence is required of chrome complex interaction with collagen.
Outcome 3
Evaluate chrome tannage practices.
Evidence requirements
3.1
Process methods for chrome tannage are evaluated in terms of procedure and
key principles.
Range
evidence is required of two of the following – pickle tannage with
soda ash basification, self basifying tannage, masked tannage, no
pickle tannage, long float.
3.2
Tanning vessels are evaluated in terms of suitability for hides and skins, or
woolskins.
3.3
Practical controls used in chrome tanning are evaluated in relation to chrome
penetration and fixation.
Range
evidence is required of five of the following – delime penetration,
pickle penetration, float length, pH, mechanical action, time,
basification rate, temperature, shrinkage temperature.
Outcome 4
Evaluate chrome tanned leather chemical and physical characteristics.
Evidence requirements
4.1
Chrome tanned leather is evaluated in terms of chemical and physical
characteristics.
Range
Planned review date
evidence is required of cationic charge, thermal stability, plus one
of the following – shape retention, substance, dyeability,
wettability, durability.
31 December 2017
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016
NZQA registered unit standard
8399 version 7
Page 3 of 3
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
24 September 1996
31 December 2014
Revision
2
16 September 1997
31 December 2014
Review
3
27 April 2000
31 December 2014
Revision
4
20 February 2002
31 December 2014
Revision
5
14 October 2004
31 December 2104
Review
6
14 December 2007
31 December 2015
Review
7
21 February 2013
N/A
Consent and Moderation Requirements (CMR) reference
0033
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMR). The
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
Comments on this unit standard
Please contact the Primary Industry Training Organisation standards@primaryito.ac.nz if
you wish to suggest changes to the content of this unit standard.
Primary Industry Training Organisation
SSB Code 101558
 New Zealand Qualifications Authority 2016