Boron oxide (B2O3)

71.63610

72.01900

215-125-8

0836

DTXSID7034387

Colorless, brittle, vitreous, semitransparent lumps or hard, white crystals|Colorless, glassy or hexagonal crystals, hygroscopic|Colorless powder or vitreous crystals

2810001000

43.37000

-1.60300

Boron oxide appears as colorless, semi-transparent glassy lumps or hard white odorless crystals. Mp 450°C; bp: 1860°C. Density: 2.46 g cm-3. Moderately soluble in water. Used as an insecticide; as the starting material for the synthesis of other boron compounds; as a fluxing agent in enamels and glasses; and in mixture with 2-6% boron nitride, as a bonding agent in the hot isostatic pressing of boron nitride ceramics.

2.46 g/cm³

450 °C

1860 °C (approx)

1860ºC

INDEX OF REFRACTION: 1.61

H2O: 36 g/L (25 ºC)

Store in a cool, dry place. Store in a tightly closed container.

0 mmHg (approx)

>1 (vs air)

Noncombustible Solid

Odorless

Slightly bitter taste

pH = 5.1 at 20 °C 1.0% solution

Enthalpy of fusion: 24.56 kJ/mol at 450 °C|Standard enthalpy of formation: -1273.5 kJ/mol (crystal); -843.8 kJ/mol (gas); molar heat capacity at 25 °C: 62.8 J/K mol (crystal); 66.9 J/K mol (gas)|Mohs' hardness: 4; mildly hygroscopic at room temperature; reaction with water is exothermic, -75.94 kJ/mol|Slowly reacts with water to form boric acid|Colorless, vitreous crystals; solubility: in water at 0 °C 1.1 g/100 cu cm, at 100 °C 15.7 g/100 cu cm; sol in acid, alcohol. Index of refraction: 1.485; MP: approx 450 °C; Density: 1.812 at 25 °C at 4 °C /oxide glass/|Heat of vaporization: 390.4 kJ/mol at 1500 K; 431.4 kJ/mol at 298 K; boiling point: 2316 °C (extrapolated); viscosity: 10.60 cP at 350 °C; 4.96 cP at 700 °C; 4.00 at 1000 °C; density: 1.8766 g/mL at 0 °C; 1.844 g/mL at 18-25 °C; 1.81 g/mL at 18-25 °C (well-annealed); 1.648 g/mL at 500 °C (quenched); 1.528 g/mL at 1000 °C (quenched); index of refraction: 1.463 at 14.4 °C; specific heat capacity: 62.969 J/kg K at 298 K; heat of formation: -1252.2 kJ at 298.15 K /Vitreous boric oxide/

No rapid reaction with air No rapid reaction with water

Salts, Acidic

BORON OXIDE is non-combustible. Of generally low chemical reactivity. Reacts exothermically but slowly with water to form boric acid, a weak acid. Reacts exothermically with strong bases. May react with strong reducing agents such as metal hydrides, metal alkyls to generate flammable or explosive gases. May react violently on contact with bromine pentafluoride. Corrosive to metals in the presence of air.

13.50 eV

Noncombustible Solid

Very corrosive to metals in the presence of oxygen

Ⅲ

2811

1

R36/37/38

S26-S37/39

ED7900000

Xi

Dry. Well closed.

Stable. Moisture sensitive. Incompatible with water.

P201-P308 + P313

H360FD

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.

Attacks metal in the presence of moist air.|Water [Note: Reacts slowly with water to form boric acid].|When a mixture of boric acid and calcium oxide in any proportion is projected into fused calcium chloride, the mass becomes incandescent.

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

Not combustible.

|Danger|H360FD: May damage fertility; May damage the unborn child [Danger Reproductive toxicity]|P201, P202, P281, P308+P313, P405, and P501|H360 (100%): May damage fertility or the unborn child [Danger Reproductive toxicity]|Aggregated GHS information provided by 653 companies from 14 notifications to the ECHA C&L Inventory.|H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]|P201, P202, P261, P264, P271, P280, P281, P304+P340, P305+P351+P338, P308+P313, P312, P337+P313, P403+P233, P405, and P501|Warning|H303: May be harmful if swallowed [Warning Acute toxicity, oral]|P261, P264, P271, P280, P304+P340, P305+P351+P338, P312, P332+P313, P337+P313, P403+P233, P405, and P501

In case of fire in the surroundings, use appropriate extinguishing media.

Skin: Wear appropriate personal protective clothing to prevent skin contact. Eyes: Wear appropriate eye protection to prevent eye contact. Wash skin: The worker should immediately wash the skin when it becomes contaminated. Remove: Work clothing that becomes wet or significantly contaminated should be removed and replaced. Change: No recommendation is made specifying the need for the worker to change clothing after the work shift. (NIOSH, 2016)|Employees should be provided with and required to use impervious clothing, gloves, face shields (eight inch minimum), and other appropriate protective clothing necessary to prevent repeated or prolonged skin contact with boron oxide.|Non impervious clothing which becomes contaminated with boron oxide should be removed promptly and not reworn until the boron oxide is removed from the clothing.|Employees should be provided with and required to use dust and splash proof safety goggles where boron oxide or non-aqueous liquids containing boron oxide may contact the eyes.|Wear appropriate personal protective clothing to prevent skin contact.|For more Personal Protective Equipment (PPE) (Complete) data for BORON OXIDE (12 total), please visit the HSDB record page.|(See protection codes)

Noncombustible

Sweep spilled substance into containers; if appropriate, moisten first to prevent dusting. Carefully collect remainder, then remove to safe place (extra personal protection: P1 filter respirator for inert particles).

SRP: The scientific literature for the use of contact lenses in industry is conflicting. The benefit 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.|During production processes, atmospheric contamination by vapors and aerosols of ... boric anhydride ... should be minimized by use of local exhaust ventilation, process mechanization, and enclosure ...|Skin that becomes contaminated with boron oxide should be promptly washed or showered with soap or mild detergent and water to remove any boron oxide. Employees who handle boron oxide or non-aqueous liquids containing boron oxide should wash their hands thoroughly with soap or mild detergent and water before eating, smoking or using toilet facilities.|SRP: Contaminated protective clothing should be segregated in such a manner so that there is no direct personal contact by personnel who handle, dispose, or clean the clothing. Quality assurance to ascertain the completeness of the cleaning procedures should be implemented before the decontaminated protective clothing is returned for reuse by the workers. Contaminated clothing should not be taken home at end of shift, but should remain at employee's place of work for cleaning.|For more Preventive Measures (Complete) data for BORON OXIDE (7 total), please visit the HSDB record page.

Potential symptoms of overexposure are irritation of eyes, skin, respiratory system; cough; conjunctivitis; skin erythema.|... May produce irritation of the nasal mucous membranes, the respiratory tract, and eyes. /Boron compounds/

Permissible Exposure Limit: Table Z-1 8-hr Time Weighted Avg: 15 mg/cu m. /Total dust/|Vacated 1989 OSHA PEL TWA 10 mg/cu m is still enforced in some states.

Recommended Exposure Limit: 10 hr Time-Weighted avg: 10 mg/cu m.

Personal protection: particulate filter respirator adapted to the airborne concentration of the substance. Sweep spilled substance into covered containers. If appropriate, moisten first to prevent dusting. Carefully collect remainder. Then store and dispose of according to local regulations.

Dry. Well closed.

Evaporation at 20 °C is negligible; a harmful concentration of airborne particles can, however, be reached quickly , especially if powdered.

The substance is irritating to the eyes, skin and respiratory tract. The substance may cause effects on the central nervous system and kidneys. This may result in impaired functions.

The substance may have effects on the upper respiratory tract. Animal tests show that this substance possibly causes toxicity to human reproduction or development.

PREVENT DISPERSION OF DUST! STRICT HYGIENE!

Use local exhaust or breathing protection.

Protective gloves. Protective clothing.

Wear safety spectacles or eye protection in combination with breathing protection.

SOURCE DOMINATED: A mean boric acid/boric oxide dust concentration of 4.1 mg/cu m has been reported in a boric acid manufacturing plant(1).

LD50 Mouse oral 3163 mg/kg|LD50 Mouse ip 1868 mg/kg

/AQUATIC SPECIES/ A study was carried out on the growth of various phytoplankton in sea water with boric acid additions. The 29-58 mg/L boric acid level (equivalent to 16-32 mg/L boric oxide) showed no inhibitory effect on the growth of any of the species tested, in fact the 58 mg/L level (32 mg/L boric oxide) appeared to stimulate growth. In general, the 290 mg/L level (160 mg/L boric oxide) depressed the growth rate of about half the total number of species to the extent of 30-70%. At the 580 mg/L level (320 mg/L boric oxide) growth was seen to be inhibited in 63% of the species and lethal to about two thirds of this percentage. The species studied included; Agmenellum quadruplicatum, Cyclotella cryptica, Dunaliella tertiolecta, Phaeodactylum tricornutum and skeletonema costatum. /Tested as boric acid. Boric oxide is the anhydride of boric acid; one part of boric oxide is equivalent to 1.776 parts of boric acid in aqueous solution./|/AQUATIC SPECIES/ Study showed that there was a significant effect on primary production when 20 um (nanoplankton) phytoplankton were treated with concentrations of 172 mg/L of boric acid (equivalent to 97 mg/L of boric oxide). When levels of nitrate, phosphate, and silicate with low temperature prevailing (November-May) consistent stimulation of primary production and carbon assimilation rates were observed in the presence of boric acid. When the nitrate, phosphate and silicate were low and the temperature was high, photosynthesis was inhibited. Treatment with boric acid inhibited photosynthesis in 5 day old unialgal cultures but enhanced photosynthesis in 14 day old cultures of certain species, showing that the effects of boron could be species specific. It appears that boric acid, under conditions of excess, could alleviate nutrient deficiency in som phytoplankters and might cause temporal variations of phytoplankton composition in coastal waters. Species studied included Skeletonema costatum, Centric diatom 10, and Cachonina niei. /Tested as boric acid. Boric oxide is the anhydride of boric acid; one part of boric oxide is equivalent to 1.776 parts of boric acid in aqueous solution./

NIOSH (NOES Survey 1981-1983) has statistically estimated that 162,342 workers (18,457 of these are female) are potentially exposed to boron oxide in the US(1). A mean boric acid/boric oxide dust concentration of 4.1 mg/cu m has been reported in a boric acid manufacturing plant(2).

Exposure Routes: inhalation, ingestion, skin and/or eye contact Symptoms: Irritation eyes, skin, respiratory system; cough; conjunctivitis; skin erythema (skin redness) Target Organs: Eyes, skin, respiratory system (NIOSH, 2016)

Eye: If this chemical contacts the eyes, immediately wash the eyes with large amounts of water, occasionally lifting the lower and upper lids. Get medical attention immediately. Contact lenses should not be worn when working with this chemical. Skin: If this chemical contacts the skin, flush the contaminated skin with water promptly. If this chemical penetrates the clothing, immediately remove the clothing and flush the skin with water promptly. If irritation persists after washing, get medical attention. Breathing: If a person breathes large amounts of this chemical, move the exposed person to fresh air at once. Other measures are usually unnecessary. Swallow: If this chemical has been swallowed, get medical attention immediately. (NIOSH, 2016)|(See procedures)

Fresh air, rest.

Rinse and then wash skin with water and soap.

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

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/|In acute poisonings, if a large amount has been ingested and the patient is seen within one hour of exposure, gastrointestinal decontamination should be considered ... .It is important to keep in mind that vomiting and diarrhea are common, and severe poisoning may be associated with seizures. Therefore induction of emesis by syrup of ipecac is probably contraindicated in these exposures. Catharsis is not indicated if diarrhea is present. /Boric acid and Borates/|If ingestion of borate has been massive (several grams), or has extended over several days, administer intravenous glucose and electrolyte solutions to sustain urinary excretion of borate. Monitor fluid balance and serum electrolytes (including bicarbonate capacity ) regularly. Monitor cardiac status by ECG. Test the urine for proteins and cells to detect renal injury, and monitor serum concentration of borate. Metabolic acidosis may be treated with sodium bicarbonate. If shock develops, it may be necessary to infuse plasma or whole blood. Administer oxygen continuously. If oliguria (less than 25 to 30 mL urine per hour) occurs, intravenous fluids must be slowed or stopped to avoid overloading the circulation. Such patients should be referred to a center capable of providing intensive care for critically ill patients. /Boric acid and Borates/|For more Antidote and Emergency Treatment (Complete) data for BORON OXIDE (7 total), please visit the HSDB record page.

/SIGNS AND SYMPTOMS/ Ingestion symptoms /include/ abdominal cramps, diarrhea, nausea, vomiting, and shock. /table/|/SIGNS AND SYMPTOMS/ Potential symptoms of overexposure are irritation of eyes, skin, respiratory system; cough; conjunctivitis; skin erythema.|/EPIDEMIOLOGY STUDIES/ /Investigators/ determined the prevalence of respiratory and eye irritation in a group of 113 workers exposed to boric acid and boric oxide at an average concentration of 4.1 mg/cu m (range,1.2 -8.5 mg/cu m). The exposed employees and 214 control workers who had never been exposed to boric acid or boric oxide and who had only low or minimal exposure to borax were interviewed regarding eye and respiratory tract irritation, nose bleeds, and other respiratory symptoms. Reports of eye irritation; dryness of mouth, nose or throat; and sore throat and productive cough were significantly more common in exposed workers.

B2O3

The substance can be absorbed into the body by inhalation of its aerosol and by ingestion.|inhalation, ingestion, skin and/or eye contact

irritation eyes, skin, respiratory system; cough; conjunctivitis; skin erythema (skin redness)

Cough. Sore throat.

Redness.

Redness. Pain.

Eyes, skin, respiratory system

Boron oxide & boric acid combined: 20% is used in textile glass fibers; 19% as a flux in enamels, frits, & glazes; 9% in glasses; 1% as a herbicide; 51% in misc applications, including use as a catalyst in oxidation of hydrocarbons, as a conditioning agent, & in manufacture of other boron compounds (1969)

GRADES: Glass or fused form; powder, technical or high purity 99.99+%

Adhesive manufacturing|Boron oxide (B2O3): ACTIVE

Method: NIOSH 500, Particulates Not Otherwise Regulated, Total; Procedure: gravimetric (filter weight); Analyte: airborne particulate material; Matrix: air; Detection Limit: 0.03 mg per sample.|Method: NIOSH 600, Particulates Not Otherwise Regulated, Respirable; Procedure: gravimetric (filter weight); Analyte: mass of respirable dust fraction; Matrix: air; Detection Limit: 0.03 mg per sample.

EPA Safer Chemical Functional Use Classes -> Enzymes and Enzyme Stabilizers|Safer Chemical Classes -> Yellow triangle - The chemical has met Safer Choice Criteria for its functional ingredient-class, but has some hazard profile issues