ISO 3856-5:1984 PDF

Paints and varnishes — Determination of "soluble" metal content — Part 5: Determination of hexavalent chromium content of the pigment portion of the liquid paint or the paint in powder form — Diphenylcarbazide spectrophotometric method

Open preview (PDF)

Title (English):

ISO 3856-5:1984

Document status:: Active
Format:: Electronic (PDF)
Number of pages:: 3
Publication date:: October 1, 1984
Edition:: ISO IS 3856 edition 2 version 1
ICS:: 87.040

Delivery type:

Full version25 €Read online 24h10 €Read online 72h15 €

Document language:

enru

Delivery time:Immediate download

Price:25 €

Description (English):

The principle consists in formation of a coloured complex from hexavalent chromium and diphenylcarbazide solution. After addition of orthophosphoric acid and sulfuric acid, spectralphotometric easurement of the colour at a wavelength in the region of 540 nm. The method is applicable to coating materials having hexavalent chromium contents in the range of about 0,05 % (m/m) to 5 % (m/m). This method id the referee method in cases of dispute. This second edition cancels and replaces the ISO 3856/5-1980, of which it constitutes a through revision.

Technical details

Technical committee: ISO/TC 256 - Pigments, dyestuffs and extenders
SKU: ISO 3856-5:1984

Abstract

Overview - ISO 3856-5:1984 (Paints and varnishes - Cr(VI) in pigments)

ISO 3856-5:1984 specifies a diphenylcarbazide spectrophotometric method for determining the “soluble” hexavalent chromium (Cr(VI)) content in the pigment portion of liquid paints or powder paints. The method measures a coloured Cr(VI)–diphenylcarbazide complex by spectrophotometry at about 540 nm and is applicable to coating materials with Cr(VI) contents of approximately 0.05% to 5% (m/m). When disputes arise over Cr(VI) results, this spectrophotometric technique is the referee method.

Key topics and technical requirements

Analytical principle: formation of a coloured complex between Cr(VI) and diphenylcarbazide after acidification; spectrophotometric measurement near 540 nm.
Scope: evaluation of the pigment portion (hydrochloric acid extract) of liquid or powder paints; measures the “soluble” fraction of hexavalent chromium.
Reagents (high level):
- Diphenylcarbazide solution (0.25 g in 50 ml acetone + 50 ml water)
- Sodium hydroxide c(NaOH) = 2 mol/L
- Sulfuric acid c(H2SO4) = 1 mol/L
- Orthophosphoric acid (~85% m/m)
- Hydrochloric acid c(HCl) = 0.07 mol/L
- Standard Cr(VI) stock (100 mg/L from potassium dichromate) and working standards (1 mg/L)
Apparatus: spectrophotometer (10 or 20 mm cells), pH‑meter, 50 ml burette, one‑mark volumetric flasks.
Calibration and measurement: prepare standard calorimetric solutions, build a calibration graph (mass of Cr(VI) in µg vs absorbance), treat test aliquots identically and read absorbance against water reference.
Sample preparation: uses the hydrochloric acid extract procedure described in ISO 6713 (preparation of acid extracts from paints).
Reporting: results expressed as percentage by mass of the paint (or pigment portion); test report must reference ISO 3856-5 and include product ID, extraction method, solvents used, and any deviations. Precision data are not provided in this edition.

Practical applications and users

Quality control laboratories in paint, coating and pigment manufacturing
Regulatory, environmental and occupational health testing for Cr(VI) compliance
Third‑party conformity testing and dispute resolution (referee method)
R&D teams assessing pigment safety, formulation changes, or substitution of chromium-containing pigments

Related standards

ISO 6713 - Preparation of acid extracts from paints (sample extraction referenced by this method)
Other parts of ISO 3856 - Determination of “soluble” metal content in paints and varnishes

Keywords: ISO 3856-5:1984, hexavalent chromium, Cr(VI), diphenylcarbazide, spectrophotometric method, paints, pigments, varnishes, chromium testing.

Related standards

Standards mentioned in the description

Abstract

Overview - ISO 3856-5:1984 (Paints and varnishes - Cr(VI) in pigments)

Key topics and technical requirements

Analytical principle: formation of a coloured complex between Cr(VI) and diphenylcarbazide after acidification; spectrophotometric measurement near 540 nm.
Scope: evaluation of the pigment portion (hydrochloric acid extract) of liquid or powder paints; measures the “soluble” fraction of hexavalent chromium.
Reagents (high level):
- Diphenylcarbazide solution (0.25 g in 50 ml acetone + 50 ml water)
- Sodium hydroxide c(NaOH) = 2 mol/L
- Sulfuric acid c(H2SO4) = 1 mol/L
- Orthophosphoric acid (~85% m/m)
- Hydrochloric acid c(HCl) = 0.07 mol/L
- Standard Cr(VI) stock (100 mg/L from potassium dichromate) and working standards (1 mg/L)
Apparatus: spectrophotometer (10 or 20 mm cells), pH‑meter, 50 ml burette, one‑mark volumetric flasks.
Calibration and measurement: prepare standard calorimetric solutions, build a calibration graph (mass of Cr(VI) in µg vs absorbance), treat test aliquots identically and read absorbance against water reference.
Sample preparation: uses the hydrochloric acid extract procedure described in ISO 6713 (preparation of acid extracts from paints).
Reporting: results expressed as percentage by mass of the paint (or pigment portion); test report must reference ISO 3856-5 and include product ID, extraction method, solvents used, and any deviations. Precision data are not provided in this edition.

Practical applications and users

Quality control laboratories in paint, coating and pigment manufacturing
Regulatory, environmental and occupational health testing for Cr(VI) compliance
Third‑party conformity testing and dispute resolution (referee method)
R&D teams assessing pigment safety, formulation changes, or substitution of chromium-containing pigments

Related standards

ISO 6713 - Preparation of acid extracts from paints (sample extraction referenced by this method)
Other parts of ISO 3856 - Determination of “soluble” metal content in paints and varnishes

Keywords: ISO 3856-5:1984, hexavalent chromium, Cr(VI), diphenylcarbazide, spectrophotometric method, paints, pigments, varnishes, chromium testing.

ISO 3856-5:1984 PDF

Technical details

Abstract

Overview - ISO 3856-5:1984 (Paints and varnishes - Cr(VI) in pigments)

Key topics and technical requirements

Practical applications and users

Related standards

Related standards

Abstract

Overview - ISO 3856-5:1984 (Paints and varnishes - Cr(VI) in pigments)

Key topics and technical requirements

Practical applications and users

Related standards

Related standards

Paints and varnishes — Preparation of acid extracts from liquid paints

Paints and varnishes — Determination of "soluble" metal content — Part 5: Determination of hexavalent chromiu…

Paints and varnishes — Determination of "soluble" metal content — Part 1: Determination of lead content — Fla…