Liquid paraffin oil is a mineral oil and is a by-product of petroleum distillation. It is transparent, colorless, odorless and tasteless oil, which is mainly composed of heavier alkanes. It is not soluble in water and is known to have low reactivity. Paraffin oil and paraffin wax have found a wide range of industrial, medical, as well as cosmetic uses in modern times. Liquid paraffin oil usually comes in two forms, heavy liquid paraffin oil and light liquid paraffin oil. It is is a very highly refined mineral oil used in cosmetics and medicine. Liquid paraffin is a hydrating and cleansing agent. Hence, it is used in several cosmetics both for skin and hair products.
DEFINITION
Light Mineral Oil is a purified mixture of liquid hydrocarbons obtained from petroleum. It may contain a suitable stabilizer.
IDENTIFICATION
A. Infrared Absorption
B. It meets the requirements in Specific Tests for Viscosity—Capillary Methods.
Limit of Polycyclic Aromatic Hydrocarbons:
To pass the test.
Acceptance criteria: The absorbance at any wavelength in the specified range of the Sample solution is NMT one-third of the absorbance of the Standard solution.
Specific Gravity: 0.818–0.880
Viscosity Capillary Methods:3.0–34.4 mm2/s for kinematic viscosity, measured with a capillary viscometer at 40 ± 0.1C
Acidity:
Sample solution: Combine 10 mL of Light Mineral Oil and 20 mL of boiling water, shake vigorously for 1 min, and allow to cool. Remove, and filter the aqueous layer.
Analysis: To 10 mL of the Sample solution add 0.1 mL of phenolphthalein.
Acceptance criteria: The solution does not produce a pink color. NMT 1.0 mL of 0.01 N sodium hydroxide is required to produce a pink color.
Readily Carbonizable Substances Test:
To pass the test.
Solid Paraffin:
Sample: Light Mineral Oil that has been dried previously in a beaker at 105c for 2 h and cooled to room temperature in a desiccator over silica gel
Analysis: Fill a tall, cylindrical, standard oil-sample bottle of colorless glass of 120-mL capacity with the Sample. Insert the stopper, and immerse the bottle in a mixture of ice and water for 4 h.
Acceptance criteria: The Sample is sufficiently clear that a black line 0.5 mm in width, on a white background, held vertically behind the bottle, is clearly visible.
Limit of Sulfur Compounds:
Solution A: Saturated solution of lead(II) oxide in sodium hydroxide (200 mg/mL)
Sample: 4.0 mL
Analysis: Combine the Sample, 2 mL of dehydrated alcohol, and 2 drops of Solution A, heat at 70C for 10 min with frequent shaking, and cool.
Acceptance criteria: No dark brown color develops.
DEFINITION
Mineral Oil is a purified mixture of liquid hydrocarbons obtained from petroleum. It may contain a suitable stabilizer.
IDENTIFICATION
A. Infrared Absorption
B. It meets the requirements in Specific Tests for Viscosity—Capillary Methods.
Limit of Polycyclic Aromatic Hydrocarbons:
To pass the test.
Acceptance criteria: The absorbance at any wavelength in the specified range of the Sample solution is NMT one-third of the absorbance of the Standard solution.
Specific Gravity: 0.845–0.905
Viscosity Capillary Methods: 34.5–150.0 mm2 ·s –1 for kinematic viscosity, measured with a capillary viscometer at 40 ± 0.1°
Acidity:
Sample: 10 mL
Analysis: Add 20 mL of boiling water to the Sample, and shake vigorously for about 1 min. Allow to cool, and draw off the separated water. To 10 mL of the filtered aqueous layer add 0.1 mL of phenolphthalein.
Acceptance criteria: The solution does not produce a pink color. NMT 1.0 mL of 0.01 N sodium hydroxide is required to produce a pink color.
Readily Carbonizable Substances Test:
To pass the test.
Acceptance criteria: The oil portion of the Sample may turn hazy, but it remains colorless or shows a slight pink or yellow color, and the acid portion of the Sample does not become darker than the Standard solution.
Solid Paraffin:
Sample: Mineral Oil that has been dried previously in a beaker at 105° for 2 h and cooled to room temperature in a desiccator over silica gel
Analysis: Fill a tall, cylindrical, standard oil-sample bottle of colorless glass of 120-mL capacity with the Sample, insert the stopper, and immerse in an ice bath for 4 h.
Acceptance criteria: The Sample is sufficiently clear that a black line 0.5 mm in width, on a white background, held vertically behind the bottle, is clearly visible.
Limit of Sulfur Compounds:
Solution A: Saturated solution of lead(II) oxide in sodium hydroxide (200 mg/mL)
Sample: 4.0 mL
Analysis: Combine the Sample, 2 mL of dehydrated alcohol, and 2 drops of Solution A, heat at 70C for 10 min with frequent shaking, and cool.
Acceptance criteria: No dark brown color develops.
DEFINITION
Purified mixture of liquid saturated hydrocarbons obtained from petroleum.
CHARACTERS
Appearance: Colourless, transparent, oily liquid, free from fluorescence in daylight.
Solubility: Practically insoluble in water, slightly soluble in ethanol (96 per cent), miscible with hydrocarbons.
IDENTIFICATION
First identification: A, C
Second identification: B, C
A. Infrared absorption spectrophotometry.
Comparison Ph. Eur. reference spectrum of liquid paraffin.
B. In a test tube cautiously boil 1 mL with 1 mL of 0.1 M sodium hydroxide, with continuous shaking, for about 30 s. On cooling to room temperature, 2 phases separate. To the aqueous phase add 0.1 mL of phenolphthalein solution. The solution becomes red.
C. Viscosity.
TESTS
Acidity or alkalinity: To 10 mL add 20 mL of boiling water and shake vigorously for 1 min. Separate the aqueous layer and filter. To 10 mL of the filtrate, add 0.1 mL of phenolphthalein solution. The solution is colourless. Not more than 0.1 mL of 0.1 M sodium hydroxide is required to change the colour of the indicator to pink.
Relative density: 0.810 to 0.875.
Viscosity: 25 mPa⋅s to 80 mPa⋅s.
Polycyclic aromatic hydrocarbons: To pass the test.
Readily carbonisable substances: To pass the test.
Solid paraffins: Dry a suitable quantity of the substance to be examined by heating at 100C for 2 h and cool in a desiccator over sulfuric acid. Place in a glass tube with an internal diameter of about 25 mm, close the tube and immerse in a bath of iced water. After 4 h, the liquid is sufficiently clear for a black line, 0.5 mm wide, to be easily seen against a white background held vertically behind the tube.
DEFINITION
Purified mixture of liquid saturated hydrocarbons obtained from petroleum.
CHARACTERS
Appearance: Colourless, transparent, oily liquid, free from fluorescence in daylight.
Solubility: Practically insoluble in water, slightly soluble in ethanol (96 per cent), miscible with hydrocarbons.
IDENTIFICATION
First identification: A, C
Second identification: B, C
A. Infrared absorption spectrophotometry.
Comparison Ph. Eur. reference spectrum of liquid paraffin.
B. In a test tube cautiously boil 1 mL with 1 mL of 0.1 M sodium hydroxide, with continuous shaking, for about 30 s. On cooling to room temperature, 2 phases separate. To the aqueous phase add 0.1 mL of phenolphthalein solution. The solution becomes red.
C. Viscosity.
TESTS
Acidity or alkalinity: To 10 mL add 20 mL of boiling water and shake vigorously for 1 min. Separate the aqueous layer and filter. To 10 mL of the filtrate, add 0.1 mL of phenolphthalein solution. The solution is colourless. Not more than 0.1 mL of 0.1 M sodium hydroxide is required to change the colour of the indicator to pink.
Relative density: 0.827 to 0.890.
Viscosity: 110 mPa⋅s to 230 mPa⋅s.
Polycyclic aromatic hydrocarbons: To pass the test.
Readily carbonisable substances: To pass the test.
Solid paraffins: Dry a suitable quantity of the substance to be examined by heating at 100C for 2 h and cool in a desiccator over sulfuric acid. Place in a glass tube with an internal diameter of about 25 mm, close the tube and immerse in a bath of iced water. After 4 h, the liquid is sufficiently clear for a black line, 0.5 mm wide, to be easily seen against a white background held vertically behind the tube.
Liquid Petrolatum; Liquid Paraffin
CAS: [8042-47-5]
DESCRIPTION
Mineral Oil, White, occurs as a colorless, transparent, oily liquid, free or nearly free from fluorescence. It is a mixture of refined liquid hydrocarbons, essentially paraffinic and naphthenic in nature, obtained from petroleum by solvent extraction and/or crystallization with subsequent purification by acid treatment and/or hydrogen treatment. It has an initial boiling point above 200C. Its average molecular weight is not less than 300. Its minimum carbon number at 5% distillation is 17. It is insoluble in water and in alcohol, is soluble in volatile oils, and is miscible with most fixed oils, but not with castor oil. It may contain any antioxidant permitted in food by the U.S. Food and Drug Administration, in an amount not greater than that required to produce its intended effect.
Function: Defoaming agent; lubricant; release agent; protective coating; glazing agent; sealing agent.
