Silicon

This chemical does not meet GHS hazard criteria for 96.3% (3142 of 3263) of all reports.

Not Classified

Reported as not meeting GHS hazard criteria by 3142 of 3263 companies (only 3.7% companies provided GHS information). For more detailed information, please visit ECHA C&L website.

Aggregated GHS information provided per 3263 reports by companies from 14 notifications to the ECHA C&L Inventory.

Reported as not meeting GHS hazard criteria per 3142 of 3263 reports by companies.

There are 11 notifications provided by 121 of 3263 reports by companies with hazard statement code(s).

Information may vary between notifications depending on impurities, additives, and other factors. The percentage value in parenthesis indicates the notified classification ratio from companies that provide hazard codes. Only hazard codes with percentage values above 10% are shown. For more detailed information, please visit ECHA C&L website.

Reported as not meeting GHS hazard criteria by 1 of 1 companies. For more detailed information, please visit ECHA C&L website.

H228: Flammable solid [Danger Flammable solids]

H320: Causes eye irritation [Warning Serious eye damage/eye irritation]

P210, P240, P241, P264+P265, P280, P305+P351+P338, P337+P317, and P370+P378 (click each P-code to see the statement)

Fresh air, rest.

Rinse skin with plenty of water or shower.

First rinse with plenty of water for several minutes (remove contact lenses if easily possible), then refer for medical attention.

Rinse mouth.

Excerpt from NIOSH Pocket Guide for Silicon:

Eye: IRRIGATE IMMEDIATELY - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Breathing: FRESH AIR - If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. Other measures are usually unnecessary.

Swallow: MEDICAL ATTENTION IMMEDIATELY - If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2024)

General First Aid:

· Call 911 or emergency medical service.

· Ensure that medical personnel are aware of the material(s) involved, take precautions to protect themselves and avoid contamination.

· Move victim to fresh air if it can be done safely.

· Administer oxygen if breathing is difficult.

· If victim is not breathing:

-- DO NOT perform mouth-to-mouth resuscitation; the victim may have ingested or inhaled the substance.

-- If equipped and pulse detected, wash face and mouth, then give artificial respiration using a proper respiratory medical device (bag-valve mask, pocket mask equipped with a one-way valve or other device).

-- If no pulse detected or no respiratory medical device available, provide continuous compressions. Conduct a pulse check every two minutes or monitor for any signs of spontaneous respirations.

· Remove and isolate contaminated clothing and shoes.

· For minor skin contact, avoid spreading material on unaffected skin.

· In case of contact with substance, remove immediately by flushing skin or eyes with running water for at least 20 minutes.

· For severe burns, immediate medical attention is required.

· Effects of exposure (inhalation, ingestion, or skin contact) to substance may be delayed.

· Keep victim calm and warm.

· Keep victim under observation.

· For further assistance, contact your local Poison Control Center.

· Note: Basic Life Support (BLS) and Advanced Life Support (ALS) should be done by trained professionals.

In Canada, an Emergency Response Assistance Plan (ERAP) may be required for this product. Please consult the shipping paper and/or the "ERAP" section.

(General first aid procedures)

Eye: Irrigate immediately - If this chemical contacts the eyes, immediately wash (irrigate) the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately.

Breathing: Fresh air

Swallow: Medical attention immediately - If this chemical has been swallowed, get medical attention immediately.

Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:

DO NOT USE WATER, FOAM OR CO2. Dousing metallic fires with water will generate hydrogen gas, an extremely dangerous explosion hazard, particularly if fire is in a confined environment (i.e., building, cargo hold, etc.). Use DRY sand, graphite powder, dry sodium chloride-based extinguishers, or class D extinguishers. Confining and smothering metal fires is preferable rather than applying water. If it can be done safely, move undamaged containers away from the area around the fire.

FIRE INVOLVING TANKS, RAIL TANK CARS OR HIGHWAY TANKS: If impossible to extinguish, protect surroundings and allow fire to burn itself out. (ERG, 2024)

Use special powder, dry sand. NO hydrous agents.

This chemical is a combustible solid. Use dry chemical, carbon dioxide, or foam extinguishers ... If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Notify local health and fire officials and pollution control agencies. From a secure, explosion-proof location, use water spray to cool exposed containers. If cooling streams are ineffective (venting sound increases in volume and pitch, tank discolors or shows any signs of deforming), withdraw immediately to a secure position ... The only respirators recommended for fire fighting are self-contained breathing apparatuses that have full facepieces and are operated in a pressure-demand or other positive-pressure mode.

If material on fire or involved in fire: Solid streams of water may spread fire. Use water in flooding quantities as fog. Use dry chemical, graphite, or dry earth. /Silicon powder, amorphous/

Water may not be effective in extinguishing the flames. /Silicon powder, amorphous/

Reacts violently with fire extinguishing agents such as water.

· CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.

· Stay upwind, uphill and/or upstream.

· Keep unauthorized personnel away.

· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area.

· Do not touch or walk through spilled material.

· Stop leak if you can do it without risk.

· Prevent entry into waterways, sewers, basements or confined areas.

Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:

IMMEDIATE PRECAUTIONARY MEASURE: Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

LARGE SPILL: Consider initial downwind evacuation for at least 50 meters (160 feet).

FIRE: If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions. (ERG, 2024)

Immediate precautionary measure

· Isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids.

Large Spill

· Consider initial downwind evacuation for at least 50 meters (160 feet).

· If tank, rail tank car or highway tank is involved in a fire, ISOLATE for 800 meters (1/2 mile) in all directions; also, consider initial evacuation for 800 meters (1/2 mile) in all directions.

Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting.

Spill handling: evacuate persons not wearing protective equipment from area of spill or leak until clean-up is complete. Remove all ignition sources. Collect powdered material in the most convenient and safe manner and deposit in sealed containers. Ventilate area after clean-up is complete. It may be necessary to contain and dispose of this chemical as a hazardous waste. If material or contaminated runoff enters waterways, notify downstream users of potentially contaminated waters. Contact your Department of Environmental Protection or your regional office of the federal EPA for specific recommendations.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

SRP: The scientific literature for the use of contact lenses by industrial workers is inconsistent. The benefits or detrimental effects of wearing contact lenses depend not only upon the substance, but also on factors including the form of the substance, characteristics and duration of the exposure, the uses of other eye protection equipment, and the hygiene of the lenses. However, there may be individual substances whose irritating or corrosive properties are such that the wearing of contact lenses would be harmful to the eye. In those specific cases, contact lenses should not be worn. In any event, the usual eye protection equipment should be worn even when contact lenses are in place.

If material not on fire and not involved in fire: Keep sparks, flames, and other sources of ignition away. Keep material out of water sources and sewers. /Silicon powder, amorphous/

Personnel protection: Avoid breathing dusts, and fumes from burning material. Avoid bodily contact with the material ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water. /Silicon powder, amorphous/

Prevent deposition of dust; closed system, dust explosion-proof electrical equipment and lighting. Prevent build-up of electrostatic charges (e.g., by grounding).

Contact lenses should not be worn when working with this chemical.

Excerpt from ERG Guide 170 [Metals (Powders, Dusts, Shavings, Borings, Turnings, or Cuttings, etc.)]:

ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. Do not touch or walk through spilled material. Stop leak if you can do it without risk. Prevent entry into waterways, sewers, basements or confined areas. (ERG, 2024)

Separated from incompatible materials. See Chemical Dangers.

Store in tightly closed containers in a cool, well-ventilated area away from strong oxidizers and other incompatible materials.

· Wear positive pressure self-contained breathing apparatus (SCBA).

· Structural firefighters' protective clothing provides thermal protection but only limited chemical protection.

39 [ppm]

71 [ppm]

420 [ppm]

10 mg/m³ (total dust), 5 mg/m³ (resp)

TWA 10 mg/m3 (total) TWA 5 mg/m3 (resp)

15.0 [mg/m3](total dust), 5 mg/m3(respirable fraction)

15 mg/m³ (total dust), 5 mg/m³ (respirable fraction)

TWA 15 mg/m3 (total) TWA 5 mg/m3 (resp) See Appendix G

See: IDLH INDEX

Substances whose adopted documentation and TLV's were withdrawn. Substance: Silicon (7440-21-3); Year Withdrawn: 2006; Reason: Insufficient data.

· DO NOT USE WATER, FOAM OR CO2.

· Dousing metallic fires with water will generate hydrogen gas, an extremely dangerous explosion hazard, particularly if fire is in a confined environment (i.e., building, cargo hold, etc.).

· Use DRY sand, graphite powder, dry sodium chloride-based extinguishers, or class D extinguishers.

· Confining and smothering metal fires is preferable rather than applying water.

· If it can be done safely, move undamaged containers away from the area around the fire.

Fire Involving Tanks, Rail Tank Cars or Highway Tanks

· If impossible to extinguish, protect surroundings and allow fire to burn itself out.

A nuisance-causing concentration of airborne particles can be reached quickly when dispersed.

May cause mechanical irritation to the eyes and respiratory tract.

Excerpt from NIOSH Pocket Guide for Silicon:

Skin: No recommendation is made specifying the need for personal protective equipment for the body.

Eyes: PREVENT EYE CONTACT - Wear appropriate eye protection to prevent eye contact.

Wash skin: No recommendation is made specifying the need for washing the substance from the skin (either immediately or at the end of the work shift).

Remove: No recommendation is made specifying the need for removing clothing that becomes wet or contaminated.

Change: No recommendation is made specifying the need for the worker to change clothing after the workshift. (NIOSH, 2024)

Wear appropriate chemical protective gloves, boots, and goggles. /Silicon powder, amorphous/

Wear appropriate eye protection to prevent eye contact.

Important additional information about respirator selection

NO open flames. Closed system, dust explosion-proof electrical equipment and lighting. Prevent deposition of dust. Prevent build-up of electrostatic charges (e.g., by grounding).

Use local exhaust or breathing protection.

Protective gloves.

Wear safety goggles.

Do not eat, drink, or smoke during work.

Silicon powder, amorphous appears as a dark brown powder. Insoluble in water and denser than water. Burns readily when exposed to heat or flames, and may be difficult to extinguish. Water may not be effective in extinguishing flames. Used to make computer microchips.

Dry Powder; Other Solid; Large Crystals; Dry Powder; Wet Solid; Other Solid; CBI; Dry Powder; Other Solid; Wet Solid

Black to gray, lustrous, needle-like crystals. [Note: The amorphous form is a dark-brown powder.]; [NIOSH]

STEEL-GREY CRYSTALS OR BLACK-TO-BROWN AMORPHOUS POWDER.

Black to gray, lustrous, needle-like crystals.

Black to gray, lustrous, needle-like crystals. [Note: The amorphous form is a dark-brown powder.]

Black to gray, lustrous, needle-like crystals or octahedral platelets (cubic system); amorphous form is dark brown powder

4271 °F at 760 mmHg (NIOSH, 2024)

3265 °C @760 [mm Hg]

2570 °F (NIOSH, 2024)

Enthalpy of fusion at melting point: 50.21 kJ/mol

Insoluble (NIOSH, 2024)

Soluble in a mixture of nitric and hydrofluoric acids and in alkalis; insoluble in nitric and hydrochloric acid

Soluble in molten alkali oxides; practically insoluble in water

Silicon and germanium are isomorphous and thus mutually soluble in all proportions; molten silicon is immiscible in both molten tin and molten lead.

Solubility in water: none

Insoluble

2.33 at 77 °F (NIOSH, 2024) - Denser than water; will sink

2.33 g/cu cm at 25 °C/4 °C

Electron mobility at 300 K: 1500 sq cm/volt/sec; hole mobility at 300 K: 500 sq cm/volt/sec; intrinsic charge density at 300 K: 1.5x10+10; electron diffusion constant at 300 K: 38; hole diffusion constant at 300 K: 13; attacked by hydrofluoric or a mixture of hydrofluoric and nitric acids; burns in fluorine, chlorine

Critical volume: 232.6 cu cm/mol; atomic density: 5X10+22 atoms/cu cm; Knoop hardness: 950-1150; volume expansion on freezing: 9.5%

Density at melting pt = 2.30 g/cu cm (solid), 2.51 g/cu cm (liquid); Heat of evaporation = 385 kJ/mol; Surface tension at melting pt = 885 mJ/sq m

2.33 g/cm³

2.33 at 77 °F

2.3296 @25 °C

(77 °F): 2.33

0 mmHg (approx) (NIOSH, 2024)

1 Pa at 1635 °C; 10 Pa at 1829 °C; 100 Pa at 2066 °C; 1 kPa at 2363 °C; 10 kPa at 2748 °C; 100 kPa at 3264 °C

0 mmHg (approx)

Dynamic viscosity = 0.88 cP at MP and 0.7 cP at 1500 °C; kinematic viscosity (calculated) = 0.347 cSt at MP and 0.28 cSt at 1500 °C /Liquid silicon/

-9.0550x10+8 J/kmol

736 dyn/cm at MP; 720 dyn/cm at 1500 °C /Liquid silicon/

Atomic number: 14; valence: 4, 2; poor conductor of electricity ... lattice constant (25 °C): 5.41987X10-8 cm; compressibility (vol/vol 0) at 25x10+3 kg/sq cm: 0.978; at 100x10+3 kg/sq cm: 0.940; dielectric constant: 13; covalent bond ionization energy at 0 K = 1.2 electron volt; band gap: 1.106 electron volt; impurity atom ionization energy: approx 0.04 electron volt; intrinsic resistivity at 300 K = 0.23 megaohm; average heat capacity (16-100 °C): 0.1774 cal/g/deg C

Temperature of transition: solid = 1683 degree K; liquid = 2750 degree K; Heat of transition: solid = 11.1 kcal/g mole; liquid = 71 kcal/g mole

Mohs hardness: 7; dielectric constant: 12; coordination number: 6

For more Other Experimental Properties (Complete) data for Silicon, Elemental (11 total), please visit the HSDB record page.

valence band parameter

atomic structure

thermal expansion coefficient

phonon wavenumber

Highly flammable. Insoluble in water. A significant dust explosion hazard.

Metals, Elemental and Powder, Active

Highly Flammable

Strong Reducing Agent

SILICON POWDER, AMORPHOUS is a reducing agent. Ignites in fluorine gas at ordinary temperatures [Mellor 2:11-13 1946-47]. Burns spontaneously in gaseous chlorine. A mixture of silicon, aluminum, and lead oxide explodes when heated [Mellor 7:657 1946-47]. When heated with an alkali carbonate, a vigorous reaction attended by incandescence occurs [Mellor 6:164 1946-47]. Reacts violently with silver fluoride [Mellor 3:389 1946-47]. Reacts with sodium-potassium alloy to form sodium silicide, which is spontaneously flammable in air [Mellor 2 Supp. 2:564 1961].

When heated it will react with water or steam to produce /hydrogen gas/; can react with oxidizing materials.

Violent reactions with alkali carbonates, oxidants, (aluminum + lead monoxide), calcium, cesium carbide, cobaltic fluoride, iodine pentafluoride, manganese trifluoride, rubidium carbide, nitrosyl fluoride, silver fluoride, sodium-potassium alloy.

Interaction /of calcium with silicon/ is violently incandescent above 1050 °C after a short delay.

Mixtures /of cesium acetylide/ with ... silicon react vigorously on heating.

For more Hazardous Reactivities and Incompatibilities (Complete) data for Silicon, Elemental (7 total), please visit the HSDB record page.

Chlorine, fluorine, oxidizers, calcium, cesium carbide, alkaline carbonates

The substance can be absorbed into the body by inhalation.

inhalation, ingestion, skin and/or eye contact

Redness. Roughness.

Redness.

irritation eyes, skin, upper respiratory system; cough

Eyes, skin, respiratory system

LC50; Rabbit (alveolar macrophages in culture); Concentration: 199 ug/mL for 20 hr (95% confidence limits 116-339 mg/mL); Conditions: temp 37 °C

LD50 Rat oral 3160 mg/kg

Immediate first aid: Ensure that adequate decontamination has been carried out. If patient is not breathing, start artificial respiration, preferably with a demand-valve resuscitator, bag-valve-mask device, or pocket mask, as trained. Perform CPR as necessary. Immediately flush contaminated eyes with gently flowing water. Do not induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. Obtain medical attention. /Irritating materials/

Basic Treatment: Establish a patent airway (oropharyngeal or nasopharyngeal airway, if needed). Suction if necessary. Encourage patient to take deep breaths. Watch for signs of respiratory insufficiency and assist ventilations if necessary. Administer oxygen by nonrebreather mask at 10 to 15 L/min. Monitor for pulmonary edema and treat if necessary ... . Monitor for shock and treat if necessary ... . Anticipate seizures and treat if necessary ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline (NS) during transport ... . Do not use emetics. For ingestion, rinse mouth and administer 5 ml/kg up to 200 ml of water for dilution if the patient can swallow, has a strong gag reflex, and does not drool ... . /Irritating materials/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in severe respiratory distress. Early intubation at the first sign of upper airway obstruction may be necessary. Positive-pressure ventilation techniques with a bag valve mask device may be beneficial. Consider drug therapy for pulmonary edema ... . Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start IV administration of D5W /SRP: "To keep open", minimal flow rate/. Use 0.9% saline (NS) or lactated Ringer's if signs of hypovolemia are present. For hypotension with signs of hypovolemia, administer fluid cautiously. Watch for signs of fluid overload ... .Treat seizures with diazepam or lorazepam ... Use proparacaine hydrochloride to assist eye irrigation ... . /Irritating materials/

/SIGNS AND SYMPTOMS/ Causes irritation of the eyes, skin, and upper respiratory system; cough. Silicon dust does not produce significant organic disease or toxic effect when exposures are kept under reasonable control. Unpleasant deposits may be caused in eyes, ears, and nasal passages, and injury to the skin and mucous membranes may be cause by the dust itself or by cleansing procedures used for its removal.

/CASE REPORTS/ ... Increased renal silicon (200 ppm dry weight; normal = 14-23 ppm) /was found/ in an adult male bricklayer who presented with proteinuria and hypertension, but who had a normal chest roentgenogram. Moderate thickening of the glomerular basement membrane was noted on transmission electron microscopy.

/ALTERNATIVE and IN VITRO TESTS/ ...The in vitro cytotoxicity of mesoporous silicon (PSi) microparticles on the Caco-2 cells /is described/ as a function of particle size fractions (1.2-75 microm), particle concentration (0.2-4 mg/mL) and incubation times (3, 11 and 24 hr). The particle size (smaller PSi particles showed higher cytotoxicity) and the surface chemistry treatment of the PSi microparticles were considered to be the key factors regarding the toxicity aspects. These effects were significant after the 11 and 24 hr exposure times, and were explained by cell-particle interactions involving mitochondrial disruption resulting from ATP depletion and reactive oxygen species production induced by the PSi surface. These events further induced an increase in cell apoptosis and consequent cell damage and cell death in a dose-dependent manner and as a function of the PSi particle size. These effects were, however, less pronounced with thermally oxidized PSi particles. Under the experimental conditions tested and at particle sizes >25 um, the non-toxic threshold concentration for thermally hydrocarbonized and carbonized PSi particles was <2 mg/mL, and for thermally oxidized PSi microparticles was <4 mg/mL.

/OTHER TOXICITY INFORMATION/ ... /The authors/ examined inorganic particles in the pulmonary hilar lymph nodes affected by idiopathic pulmonary fibrosis (IPF)/usual interstitial pneumonia (UIP) to investigate whether inhaled elements are involved in the etiology, and whether there is an increasing risk of developing IPF/UIP. Twenty-three IPF/UIP cases and 23 controls without IPF/UIP were investigated. Pulmonary hilar lymph nodes constituted the study material. The elemental analysis was performed using scanning electron microscopy with an energy dispersive X-ray spectroscope, and ... particles /were analyzes/ quantitatively and qualitatively. The results showed that the cases contained silicon and aluminum as compared with the control in lymph nodes, and these deposits were statistically significantly associated with an increased risk of IPF/UIP (adjusted odds were 2.99, 95% CI: 1.29-6.85 and 57.84, 95% CI: 1.45-2306.19, respectively)...

/LABORATORY ANIMALS: Acute Exposure/ ... Slight pulmonary epithelial lesions /were found/ in rabbits after intratracheal instillation of silicon dust at 25 mg.

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ When guinea pigs and albino rats received an ip injection of 0.1 to 0.2 g of 99.85% elemental silicon and evaluated at up to 60 days after treatment, only minor local trauma and foreign-body reaction developed; parenterally, elemental silicon was considered biologically inert.

/GENOTOXICITY/ The genotoxicity of silicon (Si) is investigated by soaking crystalline Si in a complete culture medium for 60 days and conducting micronuclei tests (MNTs) utilizing hamster ovary (CHO) cells and its Ku80 deficient CHO mutant (xrs5) cells (DNA double-strand breaks repair deficiency). The intracellular concentrations of reactive oxygen/nitrogen species (ROS/RNS) on Si are determined to elucidate the relationship between ROS/RNS and Si-induced genotoxicity by using CHO cells. The cells are treated with ROS scavenger (dimethyl sulfoxide) and MNT are performed. The results indicate that the intracellular concentration of ROS and nitrogen oxide (NO) on Si is higher than those on the control group by about 38% and 12%. ROS/RNS include superoxide (O(2)*(-)) anion, NO, and peroxynitrite (ONOO(-)) which can injure chromosomes and induce high cellular DNA double-strand breaks (DSBs).

/ALTERNATIVE and IN VITRO TESTS/ ... The objective of this study was to compare biological responses of silicon nanoparticles (SNs, 3 nm diameter) with silicon microparticles (SMs, approximately 100-3000 nm diameter) in cultured murine macrophages (RAW 264.7) using standard protocols for assessing cytotoxicity/cell viability and inflammatory responses developed for micron-sized particles. SNs and SMs were exposed to macrophages with and without addition of endotoxin lipopolysaccharide (LPS), a positive inducer of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 (IL-6), and nitric oxide (NO). Cytotoxicity was assayed using the dye exclusion and MTT assays. Cell supernatants were assayed for production TNF-alpha, IL-6 and NO. SNs at concentrations < or = 20 ug/mL exhibited no cytotoxicity or inflammatory responses; however, SNs and SMs >20 and 200 ug/mL, respectively, increased cytotoxicity compared with controls. SMs induced concentration-related increases in TNF-alpha and IL-6 production; in contrast, the production of these cytokines was shown to decrease with increasing concentrations of SNs. NO production was not induced by SNs or SMs alone. Fluorescence microscopy demonstrated that SNs were associated with the macrophages, either internalized or attached to cell membranes...

/ALTERNATIVE and IN VITRO TESTS/ Cytotoxicity test with silicon (fine gray powder with particle size of 0.1 - 2.0 um). Alveolar macrophages washed from lungs of New Zealand white rabbits were incubated with silicon powder at 37 °C for 20 hr on a rocker platform. 9 concentrations between 30 and 1000 ug/mL in suspension were tested; cell viability determined after staining with trypan blue (supravital stain). 16 observations per dose. Negative and positive controls. Results: silicon powder had an LC50 of 199 ug/mL (95% confidence limits 116-339 mg/mL). Apparently no water soluble component was responsible for cytotoxicity. Classified by USEPA as extremely cytotoxic.

Silicon is not found free in nature, but occurs chiefly as the oxide, and as silicates. Sand, quartz, rock crystal, amethyst, agate, flint, jasper, and opal are some of the oxide forms. Granite, hornblende, asbestos, feldspar, clay mica, etc. are but a few of the numerous silicate minerals. Twenty-four radioactive isotopes are recognized. Silicon makes up 25.7% of the earth's crust, by weight, and is the second most abundant element.

Three naturally occurring isotopes: 28 (92.18%); 29 (4.71%); 30 (3.12%) ... Found as silica (quartz, sand, sandstone) or as silicate (feldspar, orthoclase, kaolinite, anorthite).

According to the 2006 TSCA Inventory Update Report, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use workers of silicon is 1,000 or greater; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 693,583 workers (28,164 of these were female) were potentially exposed to silicon in the US(1).

Silicon is not found free in nature, but occurs chiefly as the oxide, and as silicates. Sand, quartz, rock crystal, amethyst, agate, flint, jasper, and opal are some of the oxide forms. Granite, hornblende, asbestos, feldspar, clay mica, etc. are but a few of the numerous silicate minerals. Twenty-four radioactive isotopes are recognized. Silicon makes up 25.7% of the earth's crust, by weight, and is the second most abundant element.

Three naturally occurring isotopes: 28 (92.18%); 29 (4.71%); 30 (3.12%) ... Found as silica (quartz, sand, sandstone) or as silicate (feldspar, orthoclase, kaolinite, anorthite).

According to the 2006 TSCA Inventory Update Report, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use workers of silicon is 1,000 or greater; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 693,583 workers (28,164 of these were female) were potentially exposed to silicon in the US(1).

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

/GUIDE 170: METALS (POWDERS, DUSTS, SHAVINGS, BORINGS, TURNINGS, OR CUTTINGS, ETC.)/ Fire or Explosion: May react violently or explosively on contact with water. Some are transported in flammable liquids. May be ignited by friction, heat, sparks or flames. Some of these materials will burn with intense heat. Dusts or fumes may form explosive mixtures in air. Containers may explode when heated. May re-ignite after fire is extinguished. /Silicon powder, amorphous/

/GUIDE 170: METALS (POWDERS, DUSTS, SHAVINGS, BORINGS, TURNINGS, OR CUTTINGS, ETC.)/ Health: Oxides from metallic fires are a severe health hazard. Inhalation or contact with substance or decomposition products may cause severe injury or death. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may cause pollution. /Silicon powder, amorphous/

/GUIDE 170: METALS (POWDERS, DUSTS, SHAVINGS, BORINGS, TURNINGS, OR CUTTINGS, ETC.)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Stay upwind. Keep unauthorized personnel away. /Silicon powder, amorphous/

/GUIDE 170: METALS (POWDERS, DUSTS, SHAVINGS, BORINGS, TURNINGS, OR CUTTINGS, ETC.)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Structural firefighters' protective clothing will only provide limited protection. /Silicon powder, amorphous/

For more DOT Emergency Guidelines (Complete) data for Silicon, Elemental (8 total), please visit the HSDB record page.

1346 170(amorphous powder)

UN 1346; Silicon powder, amorphous

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

Flammable Solid

UN Hazard Class: 4.1; UN Pack Group: III