ANSI IT4 152:2001 pdf free download – Processing Chemicals – Specifications for Formaldehyde 37% Solution with Stabilizer
1 Scope
This standard establishes criteria for the purity of photographic-grade formaldehyde 37% solution (DANGER:<<B>>, <F>) 1) with stabilizer and specifies the tests to be used to determine the purity.
2 Normative references
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid standards.
ISO 10349-1:1992, Photography – Photographic-grade chemicals – Test methods – Part 1: General.
ISO 10349-5:1992 (R1999), Photography – Photographic-grade chemicals – Test methods – Part 5: Determination of heavy metals and iron content.
ISO 10349-7:1992 (R1999), Photography – Photographic-grade chemicals – Test methods – Part 7: Determination of alkalinity or acidity.
3 General
3.1 Physical properties
Formaldehyde, CH 2 O, 37% solution with stabilizer exists as a clear colorless liquid with a pungent odor and irritating vapors. Formaldehyde has a relative molecular mass of 30.03.
3.2 Hazardous properties
Formaldehyde solutions are hazardous and can cause irritation of the eyes, skin, and respiratory system. Use only with adequate ventilation.
3.3 Storage
Formaldehyde shall be stored in properly sealed containers away from oxidizing and alkaline materials where ambient temperatures remain between 21°C – 27°C. Avoid prolonged exposure to temperatures below 4°C.
5 Reagents and glassware
All reagents, materials, and glassware shall conform with the requirements specified in ISO 10349-1 unless otherwise noted. The hazard warning symbols, used as a reminder in those steps detailing handling operations, are defined in ISO 10349-1. These symbols are used to provide information to the user and are not meant to provide conformance with hazardous labeling requirements, as these vary from country to country.
7.1.3 Procedure
Place approximately 3 ml of a test portion of the the formaldehyde sample (<<B>>,<F>) into a tared glass- stoppered weighing bottle having a small diameter, and weigh to the nearest 0.001 g. Quantitatively transfer the contents of the weighing bottle into a 250-ml Erlenmeyer flask containing 10 ml of distilled water and mix thoroughly. Pipette 50 ml of 1 mol/l sodium hydroxide solution (7.1.2.1) (<<C>>) followed immediately, but slowly, by 50 ml of freshly prepared 3% hydrogen peroxide solution (7.1.2.2). Place a watch glass over the flask, and heat the mixture on a steam bath for 5 min with occasional swirling. Cool, let stand for 30 min, and titrate to a blue-green color with 0.5 mol/l sulfuric acid solution (7.1.2.3) using 3 drops of bromthymol blue indicator (7.1.2.5).