Health and safety Titanium dioxide nanoparticle

1 health , safety

1.1 consumer
1.2 occupational
1.3 environmental

1.3.1 toxicity

health , safety
consumer

for sunscreens, health risk dermal exposure on intact skin considered extremely low, , outweighed risk of ultraviolet radiation damage including cancer not wearing sunscreen. tio2 nanoparticles considered safer other substances used uv protection. however, there concern skin abrasions or rashes, or accidental ingestion of small amounts of sunscreen, possible exposure pathways. aerosol spray sunscreens more significant risk inhalation exposure, more hazardous. cosmetics containing nanomaterials not required labeled in united states, although in european union.

occupational

inhalation exposure common route of exposure airborne particles in workplace. u.s. national institute occupational safety , health has classified inhaled ultrafine tio2 potential occupational carcinogen due lung cancer risk in studies on rats, recommended exposure limit of 0.3 mg/m time-weighted average 10 hr/day during 40-hour work week. in contrast fine tio2 (which has particle sizes below ~4 μm), had insufficient evidence classify potential occupational carcinogen, , has higher recommended exposure limit of 2.4 mg/m. lung tumor response observed in rats exposed ultrafine tio2 resulted secondary genotoxic mechanism related physical form of inhaled particle, such surface area, rather chemical compound itself, although there insufficient evidence corroborate in humans. in addition, when finely dispersed in air , in contact sufficiently strong ignition source, tio2 nanoparticles may present dust explosion hazard.

standard controls , procedures health , safety hazards of nanomaterials relevant tio2 nanoparticles. elimination , substitution, desirable approaches hazard control, may possible through choosing properties of particle such size, shape, functionalization, , agglomeration/aggregation state improve toxicological properties while retaining desired functionality, or replacing dry powder slurry or suspension in liquid solvent reduce dust exposure. engineering controls, ventilation systems such fume hoods , gloveboxes, primary class of hazard controls on day-to-day basis. administrative controls include training on best practices safe handling, storage, , disposal of nanomaterials, proper labeling , warning signage, , encouraging general safety culture. personal protective equipment used typical chemicals appropriate nanomaterials, including long pants, long-sleeve shirts, closed-toed shoes, safety gloves, goggles, , impervious laboratory coats, , in circumstances respirators may used. exposure assessment methods include use of both particle counters, monitor real-time quantity of nanomaterials , other background particles; , filter-based samples, can used identify nanomaterial, using electron microscopy , elemental analysis.

environmental

sunscreens containing tio2 nanoparticles can wash off natural water bodies, , can enter wastewater when people shower. studies have indicated tio2 nanoparticles can harm algae , animals , can bioaccumulate , bioconcentrate, although must weighed against effect of other substances used uv protection. u.s. environmental protection agency not consider physical properties such particle size in classifying substances, , regulates tio2 nanoparticles identically other forms of tio2.

toxicity

titanium dioxide has been found toxic plants , small organisms such worms, nematodes, , insects. toxicity of tio2 nanoparticles on nematodes increases smaller nanoparticle diameter 7 nm nanoparticles relative 45 nm nanoparticles, growth , reproduction still affected regardless of tio2 nanoparticle size. release of titanium dioxide soil can have detrimental effect on ecosystem in place due hindrance of proliferation , survival of soil invertebrates; causes apoptosis stunts growth, survival, , reproduction in these organisms. these invertebrates responsible decomposition of organic matter , progression of nutrient cycling in surrounding ecosystem. without presence of these organisms, soil composition suffer.