A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 1-9

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Yellow Iron Oxide

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Key Data

Formula: FeO(OH).H₂O or Fe(OH)₃
CAS: 51274-00-1
Other names: Iron (III) hydroxide, hydrated iron oxide
Appearance: Lemon to dark yellow powder
Solubility in water: Insoluble
Thermal decomposition: Dehydrates to red iron oxide between 80 and 160°C
Oxidation:
Softening Point:
Melting Point: Not applicable due to thermal decomposition
Boiling Point:
Dustiness:

Composition/Impurities

Uses

Colourant for glazes

Radioactivity

Exposure Routes

Skin and Eye Exposure

No adverse effects

Skin Absorption

Not absorbed

Inhalation

The prolonged inhalation of high concentrations can produce a benign pneumoconiosis without impairment of lung morphology, function or symptoms. Although this may show up on lung X-rays, unlike silica this does not result in fibros or other damage to the lungs.

Particles are rods about 1.6µm long but with the diameter mostly below 0.1µm.

Ingestion

Only about 2% of ingested yellow iron oxide is absorbed by the digestive system (though this increases markedly with ascorbic acid - Vitamin C).

Toxicity

There are very few toxicity tests on this material, but also there are no known toxicity reports other than from the generic dust hazards.

Results from red iron oxide should not be read across, due to the much higher proportion of nanoparticles in the yellow oxide.

Acute

Skin

Inhalation

Ingestion

Repeat Dose

Skin

Inhalation

Ingestion

Genotoxicity

The material is not reported to have any genotoxicity.

Carcinogenicity

The material is not reported to be a carcinogen.

Reproductive Toxicity

There is no data on effects on fertility, reproductive toxicity or effects on or via lactation.

Fire Hazard

Health and Safety Practice

Normal dust precautions.

Disposal

Normal waste disposal. Not harmful to aquatic life.

Regulatory Requirements

None

Dust Limits

Regulator	8hr TWA mg/m³	15 min TWA mg/m³	Notes
UK HSE	5	10	Iron oxide fume (as Fe)