Boron

Amorphous, 2.350 g/cu cm; alpha-rhombohedral, 2.46 g/cu cm; alpha-tetragonal, 2.31 g/cu cm; beta-rhombohedral, 2.35 g/cu cm

2.45 @25 °C

Polymorphic: alpha-rhombohedral form, clear red crystals; beta-rhombohedral form, black; alpha-tetragonal form, black, opaque crystals with metallic luster; amorphous form, black or dark brown powder; other crystal forms are known but not entirely characterized

Filaments, powder, whiskers, single crystals

Insoluble in water; unaffected by aqueous hydrochloric and hydrofluoric acids; when finely divided it is soluble in boiling nitric and sulfuric acids and in molten metals such as copper, iron, magnesium, aluminum, calcium; reacts vigorously with fused sodium peroxide or with a fusion mixture of sodium carbonate or potassium nitrate

Soluble in concentrated nitric and sulfuric acids; insoluble in water, alcohol, ether

4,000 °C

4000 °C @760 [mm Hg]

2,075 °C

2075 °C

1.56X10-5 atm (0.0119 mm Hg) at 2140 °C

0.0119 [mm Hg] @2140 °C

Other Solid; Dry Powder; CBI

Crystals or yellow to brown solid; [Sax] Sold as filaments, powders, whiskers, and crystals; [Hawley]

Atomic number 5; naturally-occurring isotopes: 10,11; three short-lived artificial isotopes: 8,12, 13

Alpha-rhombohedral form, 12 atoms/unit cell; beta-rhombohedral form, 105 atoms/unit cell; alpha-tetragonal form, 50 atoms/unit cell

The alpha-rhombohedral form of boron is the simplest crystal structure with slightly deformed cubic close packing, which degrades at 1200 °C and at 1500 it converts to beta-rhombohedral boron, which is the most thermodynamically stable form.

Crystalline boron is very inert. Low purity, higher temperature, and changes in or lack of crystallinity all increase the chemical reactivity.

For more Other Experimental Properties (Complete) data for BORON, ELEMENTAL (9 total), please visit the HSDB record page.

This chemical does not meet GHS hazard criteria for 52.2% (253 of 485) of all reports.

Warning

H302 (46.4%): Harmful if swallowed [Warning Acute toxicity, oral]

P264, P270, P301+P317, P330, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 485 reports by companies from 12 notifications to the ECHA C&L Inventory.；Reported as not meeting GHS hazard criteria per 253 of 485 reports by companies.；There are 10 notifications provided by 232 of 485 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.

Chemical: Boron

Hazard Traits - Developmental Toxicity; Environmental tox；Authoritative List - CA NLs; CWA 303(d)；Report - if used as a fragrance or flavor ingredient

Boron is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Boron are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 31-01-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/14776

Boron: Does not have an individual approval but may be used under an appropriate group standard

Boron is a compound that occurs in nature. It is often found combined with other substances to form compounds called borates. Common borate compounds include boric acid, salts of borates, and boron oxide. Several companies in the United States produce most of the world's borates by processing boron compounds. Borates are used mostly to produce glass. They are also used in fire retardants, leather tanning industries, cosmetics, photographic materials, soaps and cleaners, and for high-energy fuel. Some pesticides used for cockroach control and some wood preservatives also contain borates.

Powder is a dust explosion hazard. Toxic by ingestion; [Sax] May cause irritation, but not generally considered hazardous to handle boric acid and borates; [Ullmann] Boron deficiency may cause reproductive injury in fish; Excess boric acid causes testicular damage in high-dose feeding studies of animals; [ACGIH] Boron is a hepatotoxic agent. [Zimmerman, p. 4] Minimal Risk Level (acute or intermediate oral dose) = 0.2 mg/kg/day (Develop.); Acute inhalation dose = 0.3 mg/m3 (Resp.); [ATSDR] See Boric acid.

Nat'l Research Council Canada; Data Sheets on Selected Toxic Elements (1982) NRCC No. 19252

USEPA; Health Advisory for Boron (Draft) (1988)

USEPA/OWRS; Quality Criteria for Water 1986 Boron (1986) EPA 440/5-86-001

DHHS/ATSDR; Toxicological Profile for Boron (1992) ATSDR/TP-91/05

WHO; Environmental Health Criteria Document 204: Boron (1998). Available from http://www.inchem.org/pages/ehc.html as of May 12, 2005.

Acute Tox. 4 (46.4%)

Acute Tox. 4 (100%)；Eye Irrit. 2A (87.5%)；Acute Tox. 4 (87.5%)；STOT SE 3 (87.5%)；Aquatic Chronic 3 (12.5%)

Acute toxicity (Oral) - Category 4

Specific target organ toxicity - Single exposure - Category 2 (respiratory organs)

(CA) CALIFORNIA 1000 ug/L

(NH) NEW HAMPSHIRE 630 ug/L

(ME) MAINE 1,400 ug/L

(MN) MINNESOTA 1,000 ug/L

(WI) WISCONSIN 960 ug/L

Reacts vigorously with fused sodium peroxide, or with a fusion mixture of sodium carbonate and potassium nitrate.

When amorphous boron is heated in dry ammonia, the reaction proceeds with incandescence and hydrogen is evolved. Boron ignites in bromine vapor at 700 °C. Boron ignites in chlorine at 410 °C. Fluorine attacks boron at ordinary temperatures, the /resulting/ mass becoming incandescent.

Concentrated nitric acid and boron react so violently that the mass is raised to incandescence.

Amorphous boron ignites when heated in dry nitrous oxide. With nitric oxide, the reaction proceeds with blinding flashes.

For more Hazardous Reactivities and Incompatibilities (Complete) data for BORON, ELEMENTAL (17 total), please visit the HSDB record page.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure 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, aquatic, and plant life; and conformance with environmental and public health regulations.

1.9 [mg/m3]

21 [mg/m3]

130 [mg/m3]

Limit for livestock is 5 ug/mL boron in water. /Boron/

0.5 mg/L maximum (USSR) /Boron in drinking water/

Developmental (effects during periods when organs are developing), Hematological (Blood Forming), Hematological (Blood Forming), Reproductive (Producing Children), Respiratory (From the Nose to the Lungs)

Developmental

IDENTIFICATION: (Elemental boron exists as a solid at room temperature, either as black monoclinic crystals or as a yellow or brown amorphous powder when impure). It is a naturally occurring element that is found in the form of borates in the oceans, sedimentary rocks, coal, shale, and some soils. Boron enters the environment mainly through the weathering of rocks, boric acid volatilization from seawater, and volcanic activity. Boron is also released from anthropogenic sources to a lesser extent. These sources include agricultural, refuse, and fuel wood burning, power generation using coal and oil, glass product manufacture, use of borates/perborates in the home and industry, borate mining/processing, leaching of treated wood/paper, and sewage/sludge disposal. HUMAN EXPOSURE: Only a few human studies have been conducted to assess health effects associated with exposure to boron compounds. The available data show that exposure is associated with short-term irritant effects on the upper respiratory tract, nasopharynx, and eye. These effects, however, appear to be short-term and reversible. The sole long-term (7-year) follow-up study failed to identify any long-term health effects. No studies have been identified that assess reproductive outcomes. Based on the lack of human data and the limited animal data, boron is not classifiable as to its human carcinogenicity. ANIMAL STUDIES: Data regarding developmental and reproductive toxicity show that lower fetal body weight in rats is the critical effect. As dose level increases, the effects seen include: further rib effects and testicular pathology in the rat, decreased fetal body weight and increased fetal cardiovascular malformations in the rabbit, and severe testicular pathology in the rat; testicular atrophy and sterility in the rat; reduced fetal body weight in the mouse. Animal studies on mice and rats showed no evidence of carcinogenicity of boric acid. /Boron and Boron compounds/

Boron and Compounds

Developmental

2 x 10 ^-1 mg/kg-day

The use and production of boron and boron compounds in products such as fiberglass, soaps, detergents, enamels, frits, glazes, and fire retardants, and their use in industries such as agriculture, metallurgy, chemical synthesis, and in nuclear applications(1-5) may result in their release to the environment through various waste streams(SRC).

/LABORATORY ANIMALS: Subchronic or Prechronic Exposure/ ... 15 mice ... /were/ exposed on an inhalation schedule of /amorphous boron/ 7 hr/day, 5 days/wk, for 30 days. Exposure levels averaged 72.8 mg/cu m with a wide standard deviation of 42.4. Median particle size was 0.67 micrometer, standard deviation 2.0. Under these exposure conditions there was scant evidence of toxicologic effects ... Mean weight loss of 7% during the first wk was later recovered in steady increases ...

Basic treatment: Establish a patent airway. Suction if necessary. Aggressive airway management may be necessary. 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 ... . For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with normal saline 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. Administer activated charcoal ... . Cover skin burns with dry sterile dressing after decontamination ... . /Boron and Related Compounds/

Advanced treatment: Consider orotracheal or nasotracheal intubation for airway control in the patient who is unconscious, has severe pulmonary edema, or is in respiratory arrest. 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. Monitor cardiac rhythm and treat arrhythmias if necessary ... . Start an IV with D5W /SRP: "To keep open", minimal flow rate/. Use lactated Ringer's if signs of hypovolemia are present. Watch for signs of fluid overload. Consider drug therapy for pulmonary edema ... . Consider vasopressors to treat hypotension without signs of hypovolemia ... . Use proparacaine hydrochloride to assist eye irrigation ... . /Boron and related compounds/

Maintain an open airway and assist ventilation if nescessary. treat coma, seizures, hypotension, and renal failure if they occur. There is no specific antidote. Administer activated charcoal (although boric acid is not well absorbed). Consider gastric lavage for large ingestions. /Boric acid, Borates, and Boron/

Hemodialysis is effective and is indicated after massive ingestions and for supportive care of renal failure. Peritoneal dialysishas not proved effective in enhancing elimination in infants. /Boric acid, Borates, and Boron/

For more Antidote and Emergency Treatment (Complete) data for BORON, ELEMENTAL (7 total), please visit the HSDB record page.

Chemical: Boron

Hazard Traits - Developmental Toxicity; Environmental tox；Authoritative List - CA NLs; CWA 303(d)；Report - if used as a fragrance or flavor ingredient

Boron is listed on the EPA's Chemical Data Reporting (CDR) system. Manufacturers and importers of Boron are required to report information about their production and use of this chemical to the EPA under the Toxic Substances Control Act (TSCA). (40 eCFR Part 711)

Status: Active Update: 31-01-2023 https://echa.europa.eu/registration-dossier/-/registered-dossier/14776

Boron: Does not have an individual approval but may be used under an appropriate group standard

(CA) CALIFORNIA 1000 ug/L

(NH) NEW HAMPSHIRE 630 ug/L

(ME) MAINE 1,400 ug/L

(MN) MINNESOTA 1,000 ug/L

(WI) WISCONSIN 960 ug/L

A micronutrient for plants; Used to make alloys, neutron absorbers, oxygen scavengers, composite materials, semiconductors, and rocket fuels; [Hawley] No known function in animal cells, but present at about 1 ppm; Human diet contains about 10-20 mg/day; [Ullmann] Boron (B2O3, BN, BBr3, B(COC2H5)3, SiBr4, BCl3, BF3, and B2H6) is used as a doping agent in semiconductor manufacturing. [CSH, p. 50]

Semiconductor Manufacturing [Category: Industry]；Plastic Composites Manufacturing [Category: Industry]

For boron (USEPA/OPP Pesticide Code: 128945) there are 0 labels match. /SRP: Not registered for current use in the U.S., but approved pesticide uses may change periodically and so federal, state and local authorities must be consulted for currently approved uses./

In nuclear chemistry as neutron absorber; in Ignitron rectifiers; in alloys, usually to harden other metals.

Boron-10 (isotope): As shield for nuclear radiation and in instruments used for detecting neutrons.

Deoxidizer in nonferrous metallurgy; grain refiner in aluminum; in delayed action fuses; igniter in radio tubes; coating material in solar batteries.

2023: 1,000,000 - <2,500,000 lb；2022: 1,000,000 - <2,500,000 lb；2021: 1,000,000 - <2,500,000 lb；2020: 1,000,000 - <2,500,000 lb

5.72X10+11 g

(2001) 536 thousand metric tons boric oxide. /Minerals and compounds sold or used by producers; includes both actual mine production and marketable products/

(2002) 518 thousand metric tons boric oxide. /Minerals and compounds sold or used by producers; includes both actual mine production and marketable products/

(2003) 560 thousand metric tons boric oxide. /Minerals and compounds sold or used by producers; includes both actual mine production and marketable products/

(2004) 562 thousand metric tons boric oxide (estimated). /Minerals and compounds sold or used by producers; includes both actual mine production and marketable products/

Boron is produced by the chemical reduction of boron compounds with reactive metals, either by nonaqueous electrolytic reduction or through thermal decomposition. Higher purified boron is produced by zone-refining or other thermal techniques.

First obtained by Moissan in 1895 by reduction of boric anhydride (B2O3) with magnesium in a thermite-type reaction, still good method for large quantities of relatively impure boron.

... Of high purity crystalline boron by vapor phase reduction of boron trichloride with hydrogen on electrically heated filaments in a flow system.

Boron is also prepared by electrolysis of fused melts ... with a boron carbide anode.

Products with purity of 87-99.8% /are available/

Grades: Technical (90-92%); 99% pure; high-purity crystals

Transportation Equipment Manufacturing；Primary Metal Manufacturing；Explosives Manufacturing

Boron: ACTIVE