YTTRIUM(III) OXIDE
Flammability | 0 | |
Toxicity | 1 | |
Body Contact | 1 | |
Reactivity | 0 | |
Chronic | 2 | |
SCALE: Min/Nil=0 Low=1 Moderate=2 High=3 Extreme=4 |
Phosphors for colour TV tubes (alloy with europium), yttrium- iron garnets for microwave
filters, stabiliser for high- temperature service materials (zirconia and silicon nitride
refractories), dopant for optical fibres and superconductors.
O3-Y2, Y2O3, yttria, "yttrium sesquioxide", "yttrium trioxide", "diyttrium trioxide"
Although ingestion is not thought to produce harmful effects, the material may still be damaging to the health of the individual following ingestion, especially where pre- existing organ (e.g. liver, kidney) damage is evident. Present definitions of harmful or toxic substances are generally based on doses producing mortality (death) rather than those producing morbidity (disease, ill-health). Gastrointestinal tract discomfort may produce nausea and vomiting. In an occupational setting however, ingestion of insignificant quantities is not thought to be cause for concern.
Although the material is not thought to be an irritant, direct contact with the eye may produce transient discomfort characterized by tearing or conjunctival redness (as with windburn). The dust may produce eye discomfort causing smarting, pain and redness.
The material is not thought to produce adverse health effects or skin irritation following contact (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable gloves be used in an occupational setting.
The material is not thought to produce adverse health effects or irritation of the respiratory tract (as classified using animal models). Nevertheless, good hygiene practice requires that exposure be kept to a minimum and that suitable control measures be used in an occupational setting. Persons with impaired respiratory function, airway diseases and conditions such as emphysema or chronic bronchitis, may incur further disability if excessive concentrations of particulate are inhaled.
Principal routes of exposure are by accidental skin and eye contact andinhalation of generated dusts. The toxicology of rare earth metal oxides has been determined by pathological and biochemical examination of rodents exposed to the oxides by oral, intraperitoneal or endotracheal routes. Weakly expressed general toxic action of the oxides is seen in acute and prolonged exposure. The dusts cause pronounced changes in the lungs. (The oxides of the rare earth metals are significantly less toxic than their salts.) Yttrium oxide, introduced endotracheally to white-rats, causes diffuse fibrosis, emphysema, small white nodules, giant cells and accumulation of dusts in the lung; the lymph nodes are enlarged. [Mogilevskaya & Raikhlin - Toxicology of Rare Earths]