Boric Acid

H360FD: May damage fertility; May damage the unborn child [Danger Reproductive toxicity]

P203, P280, P318, P405, and P501 (click each P-code to see the statement)

This chemical does not meet GHS hazard criteria for < 0.1% (1 of 2123) of reports.

H360 (88.7%): May damage fertility or the unborn child [Danger Reproductive toxicity]

H360FD (11.2%): May damage fertility; May damage the unborn child [Danger Reproductive toxicity]

Aggregated GHS information provided per 2123 reports by companies from 49 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Reported as not meeting GHS hazard criteria per 1 of 2123 reports by companies.

There are 48 notifications provided by 2122 of 2123 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.

H360 (100%): May damage fertility or the unborn child [Danger Reproductive toxicity]

Aggregated GHS information provided per 241 reports by companies from 5 notifications to the ECHA C&L Inventory.

H315: Causes skin irritation [Warning Skin corrosion/irritation]

H319: Causes serious eye irritation [Warning Serious eye damage/eye irritation]

H335: May cause respiratory irritation [Warning Specific target organ toxicity, single exposure; Respiratory tract irritation]

H360: May damage fertility or the unborn child [Danger Reproductive toxicity]

H370: Causes damage to organs [Danger Specific target organ toxicity, single exposure]

H402: Harmful to aquatic life [Hazardous to the aquatic environment, acute hazard]

P203, P260, P261, P264, P264+P265, P270, P271, P273, P280, P302+P352, P304+P340, P305+P351+P338, P308+P316, P318, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

P203, P260, P261, P264, P264+P265, P270, P271, P280, P302+P352, P304+P340, P305+P351+P338, P308+P316, P318, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

H303: May be harmful if swallowed [Warning Acute toxicity, oral]

H372: Causes damage to organs through prolonged or repeated exposure [Danger Specific target organ toxicity, repeated exposure]

P203, P260, P261, P264, P264+P265, P270, P271, P280, P301+P317, P302+P352, P304+P340, P305+P351+P338, P308+P316, P318, P319, P321, P332+P317, P337+P317, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Fresh air, rest.

Rinse and then wash skin with water and soap.

Rinse with plenty of water (remove contact lenses if easily possible).

Rinse mouth. Do NOT induce vomiting. Refer immediately for medical attention.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SKIN: IMMEDIATELY flood affected skin with water while removing and isolating all contaminated clothing. Gently wash all affected skin areas thoroughly with soap and water. If symptoms such as redness or irritation develop, IMMEDIATELY call a physician and be prepared to transport the victim to a hospital for treatment.

INHALATION: IMMEDIATELY leave the contaminated area; take deep breaths of fresh air. If symptoms (such as wheezing, coughing, shortness of breath, or burning in the mouth, throat, or chest) develop, call a physician and be prepared to transport the victim to a hospital. Provide proper respiratory protection to rescuers entering an unknown atmosphere. Whenever possible, Self-Contained Breathing Apparatus (SCBA) should be used; if not available, use a level of protection greater than or equal to that advised under Protective Clothing.

INGESTION: DO NOT INDUCE VOMITING. If the victim is conscious and not convulsing, give 1 or 2 glasses of water to dilute the chemical and IMMEDIATELY call a hospital or poison control center. Be prepared to transport the victim to a hospital if advised by a physician. If the victim is convulsing or unconscious, do not give anything by mouth, ensure that the victim's airway is open and lay the victim on his/her side with the head lower than the body. DO NOT INDUCE VOMITING. IMMEDIATELY transport the victim to a hospital. (NTP, 1992)

Fire Extinguishing Agents: Water fog. (USCG, 1999)

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

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. Wash away remainder with plenty of water.

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.

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.

Containers of boric acid should bear an autoclavable poison label.

Avoid depositing product onto exposed food and feed processing, preparation and serving surfaces, or introducing material into air. Do not apply when food processing facility is in operation. Any product visible after application must be brushed into cracks and crevices, or removed. Place product in areas that are inaccessible to children and pets.

SMALL SPILLS AND LEAKAGE: If you spill this chemical, you should dampen the solid spill material with water, then transfer the dampened material to a suitable container. Use absorbent paper dampened with water to pick up any remaining material. Seal your contaminated clothing and the absorbent paper in a vapor-tight plastic bag for eventual disposal. Wash all contaminated surfaces with a strong soap and water solution. Do not reenter the contaminated area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

STORAGE PRECAUTIONS: You should store this material under ambient temperatures. (NTP, 1992)

Separated from strong bases.

Preserve in well-closed containers.

10.0 [mg/m3], inhalable fraction[German Research Foundation (DFG)]

6.0 [mg/m3]

21 [mg/m3]

130 [mg/m3]

2.0 [mg/m3], inhalable fraction

6.0 [mg/m3], inhalable fraction

8 hr Time Weighted Avg (TWA): 2 mg/cu m (inhalable fraction); 15 min Short Term Exposure Limit (STEL): 6 mg/cu m (inhalable fraction). /Borate compounds, inorganic/

A4; Not classifiable as a human carcinogen. /Borate compounds, inorganic/

(inhalable fraction): 2 mg/m

2 mg/m³ (inhalable particulate matter) [2004]

6 mg/m³ (inhalable particulate matter) [2004]

(inhalable fraction): 10 mg/m

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

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

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 respiratory tract. May cause mechanical irritation to the eyes. The substance may cause effects on the central nervous system and kidneys. This may result in impaired functions.

Repeated or prolonged contact with skin may cause dermatitis. The substance may have effects on the testes. Animal tests show that this substance possibly causes toxicity to human reproduction or development.

An exemption from the requirement of a tolerance is established for residues of the pesticidal chemical boric acid and its salts, borax (sodium borate decahydrate), disodium octaborate tetrahydrate, boric oxide (boric anhydride), sodium borate and sodium metaborate, in or on raw agricultural commodities when used as an active ingredient in insecticides, herbicides, or fungicides preharvest or postharvest in accordance with good agricultural practices.

Residues of boric acid are exempted from the requirement of a tolerance when used in accordance with good agricultural practice as inert (or occasionally active) ingredients in pesticide formulations applied to growing crops only. Use: sequestrant. Limit: none.

Chemical goggles; chemical resistant gloves and clothing. (USCG, 1999)

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.

Do not eat, drink, or smoke during work.

Boric acid is an odorless white solid. Melting point 171 °C. Sinks and mixes with water. (USCG, 1999)

Dry Powder; Other Solid; Large Crystals; Dry Powder; Large Crystals; Liquid; Other Solid

Colourless, odourless, transparent crystals or white granules or powder; slightly unctuous to the touch; occurs in nature as the mineral sassolite

Colorless crystals or white powder or granules; odorless; [Merck Index] White odorless powder; [Alfa Aesar MSDS]

ODOURLESS COLOURLESS CRYSTALS OR WHITE POWDER.

Odorless white solid.

Colorless, transparent crystals or white granules or powder

Colorless triclinic crystals

White waxy triclinic solid plates

Odorless

Faintly bitter

572 °F at 760 mmHg (decomposes) (NTP, 1992)

340 °F (NTP, 1992)

170.9 °C

10 to 50 mg/mL at 66 °F (NTP, 1992)

Soluble in hot water, partially soluble in cold water

Slightly unctuous to touch; volatile with steam; solubility in water increased by hydrochloric, citric or tartaric acids

Solubility: in glycerol 17.5% at 25 °C; ethylene glycol 18.5% at 25 °C; in methanol 173.9 g/L at 25 °C; in ethanol 94.4 g/L at 25 °C; in acetone 0.6% at 25 °C; ethyl acetate 1.5% at 25 °C

Water solubility: 2.52% at 0 °C; 3.49% at 10 °C; 4.72% at 20 °C; 6.23% at 30 °C; 8.08% at 40 °C; 10.27% at 50 °C; 12.97% at 60 °C; 15.75% at 70 °C; 19.10% at 80 °C; 23.27% at 90 °C; 27.53% at 100 °C

Solubility in water is increased by hydrochloric acid

In water, 5.0X10+4 mg/L at 25 °C

50 mg/mL at 25 °C

Solubility in water, g/100ml at 20 °C: 5.6

1.435 at 68 °F (USCG, 1999) - Denser than water; will sink

1.5 g/cu cm

Relative density (water = 1): 1.5

1.435 @25 °C

1.6X10-6 mm Hg at 25 °C (2.136X10-4 Pa); log P (in Pa) = 26.83 - 9094/T where T is deg K

Vapor pressure at 20 °C: negligible

log Kow = 0.175

Stable in air.

...Stable up to 100 °C

Boric acid decomposes in heat above 100 °C forming boric anhydride and water.

3,8-4,8 (3,3 % aqueous solution)

pH = 5.1 (0.1 Molar)

Index of refraction: 1.337, 1.461, 1.462

Ka = 5.80X10-10 at 25 °C (pKa = 9.24)

Loses 1.5H2O at 300 °C

Standard enthalpy of formation: -1094.3 kJ/mol (crystal); -994.1 kJ/mol (gas)

pH at 20 °C: 6.1 (0.1% solution); 5.1 (1.0% solution); 3.7 (4.5% solution)

Water soluble.

Acids, Weak

BORIC ACID is a very weak acid. Incompatible with alkali carbonates and hydroxides. During an attempt to make triacetyl borate, a mixture of boric acid and acetic anhydride exploded when heated to 58-60 °C [Chem. Eng. News 51:(34) 1973]. Reacts violently with the strong reducing agent potassium metal.

During an attempt to make triacetyl borate, a mixture of boric acid and acetic anhydride exploded when heated to 58-60 °C.

A mixture of potassium and /boric acid/ ... may explode on impact ...

Incompatible /with/ alkali carbonates and hydroxides.

The Expert Panel concludes that Sodium Borate and Boric Acid, in concentrations less than or equal to 5 percent, are safe as cosmetic ingredients when used as currently recommended; however, cosmetic formulations containing free Sodium Borate or Boric Acid at this concentration should not be used on infant skin or injured skin. Note: In 2003, the CIR Expert Panel considered available new data on these ingredients and reaffirmed the above conclusion.

Safe for use in cosmetics, with qualifications

Cancer Classification: Group E Evidence of Non-carcinogenicity for Humans

A4; Not classifiable as a human carcinogen. /Borate compounds, inorganic/

Boric Acid

TR-324: Toxicology and Carcinogenesis Studies of Boric Acid (CASRN 10043-35-3) in B6C3F1 Mice (Feed Studies) (1987 )

03/26/86

Chemical Not Tested in Species/Sex

No Evidence

Under the conditions of these 2--year feed studies, there was no evidence of carcinogenicity of boric acid at doses of 2,500 or 5,000 ppm for male or female B6C3F1 mice. Testicular atrophy and interstitial cell hyperplasia were observed in high dose male mice. The decrease in survival of dosed male mice may have reduced the sensitivity of this study.

No indication of carcinogenicity to humans (not listed by IARC).

The substance can be absorbed into the body by inhalation of dust and by ingestion.

Cough. Sore throat.

No acute symptoms expected.

Redness. Pain.

Nausea. Vomiting. Diarrhoea. Abdominal pain. Skin rash. Headache. Drowsiness. Convulsions.

Neurotoxin - Other CNS neurotoxin

Occupational hepatotoxin - Secondary hepatotoxins: the potential for toxic effect in the occupational setting is based on cases of poisoning by human ingestion or animal experimentation.

Reproductive Toxin - A chemical that is toxic to the reproductive system, including defects in the progeny and injury to male or female reproductive function. Reproductive toxicity includes developmental effects. See Guidelines for Reproductive Toxicity Risk Assessment.

ACGIH Carcinogen - Not Classifiable.

LCLo (rat) = 28 mg/m3/4hr

LD50 Mouse iv 1780 mg/kg bw

LD50 Mouse sc 2070 mg/kg bw

LC50 Rat inhalation >0.16 mg/L 4hr

LD50 Rat oral 3000-4000 mg/kg bw

For more Non-Human Toxicity Values (Complete) data for BORIC ACID (15 total), please visit the HSDB record page.

EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration.

... Genetic effects of boric acid and borax (2.5, 5 and 10 microm) on cultures with and without TiO(2) addition. No significant increase in /sister-chromatid exchanges/ (SCE) and micronuclei frequencies were observed at all concentrations of boron compounds. However, TiO(2)-induced SCE and micronuclei could be reduced significantly by the presence of boric acid and borax. In conclusion, this study indicated for the first time that boric acid and borax led to an increased resistance of DNA to damage induced by TiO(2).

Boric acid enhanced action of hypnotics, but devoid of activity itself.

The usefulness of N-acetylcysteine (NAC) as a chelating agent was studied for ... boric acid. Mature Sprague-Dawley rats were intoxicated; urinary excretion rates of intoxicant and total urine volume were determined during treatment. N-acetylcysteine proved to be the most effective agent at increasing the excretion of boron and was also able to reverse the oliguria associated with this chemical.

... Previous results have shown that exposure of pregnant rats on GD10 to either hyperthermia (42C) or boric acid (BA) specifically targets segmentation patterns. Exposure to hyperthermia increased the prevalence of fused and/or reduced numbers of vertebrae and ribs, primarily in the thoracic area. BA (500-1000 mg/kg, single oral dose) resulted in a significant increase in segmentation defects similar to those seen after hyperthermia, with a greater incidence in lumbar defects. In this study, we focused on the interaction of these two agents and their effects on axial skeletal development. Pregnant rats were treated on GD10 as follows: Anesthesia with Nembutal (30 mg/kg), followed by oral dosing with either water or BA (500 mg/kg) and immersion in a water bath at 37C (30 min) or 42C (rectal temp maintained at 42C for 5 min). After delivery, pups were evaluated on postnatal day (PND) 1 and 3 for number, sex, and weight. No differences were seen in litter size, pup survival, or pup weight in any of the groups. On PND3, pups were examined and processed for skeletal staining with alizarin red and alcian blue. Preliminary data indicate an increase in skeletal alterations with BA+37C (47%), water+42C (75%), or BA+42C (67%), as compared to water+37C controls (0%). Alterations included defects in ribs and vertebrae and a decrease in the number of presacral vertebrae. Because the incidence of segmentation defects in the water+42C group was high, any interaction between BA and hyperthermia might have been obscured...

The diagnoses of boric acid poisoning can be confirmed with the measurement of blood or serum boric acid levels (nL=1.4 nmol/mL), but this test is not routinely available. Treatment of boric acid toxicity is mainly supportive. Activated charcoal is not recommended because of its relatively poor adsorptive capacity for boric acid. In cases of massive oral overdose or renal failure, hemodialysis, or perhaps exchange transfusion in infants, may be helpful in shortening the half-life of boric acid.

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/

If renal failure occurs, hemodialysis may be necessary to maintain fluid balance and normal extracellular fluid composition. Hemodialysis has had limited success in enhancing clearance of borates. Peritoneal dialysis has been performed in borate poisoning and is felt to be as effective as, and safer than, exchange transfusion in removing borate. No large study has been done, but it is still used somewhat less frequently than hemodialysis. /Boric acid and Borates/

For more Antidote and Emergency Treatment (Complete) data for BORIC ACID (10 total), please visit the HSDB record page.

No specific considerations are needed for boric acid or borates except for general health and liver and kidney function. /Boric acid and borates/

/HUMAN EXPOSURE STUDIES/ ... Collected boron exposure/dose measures in workplace inhalable dust, dietary food/fluids, blood, semen, and urine from boron workers and two comparison worker groups (n=192) over three months and determined correlations between boron and semen parameters (total sperm count, sperm concentration, motility, morphology, DNA breakage, apoptosis and aneuploidy). Blood boron averaged 499.2 ppb for boron workers, 96.1 and 47.9 ppb for workers from high and low environmental boron areas (p<0.0001). Boron concentrated in seminal fluid. No significant correlations were found between blood or urine boron and adverse semen parameters. Exposures did not reach those causing adverse effects published in animal toxicology work but exceeded those previously published for boron occupational groups.

/HUMAN EXPOSURE STUDIES/ ... The present study was conducted to investigate the reproductive effects of boron exposure in workers employed in boric acid production plant in Bandirma, Turkey. In order to characterize the external and internal boron exposures, boron was determined in biological samples (blood, urine, semen), in workplace air, in food, and in water sources. Unfavorable effects of boron exposure on the reproductive toxicity indicators (concentration, motility, morphology of the sperm cells and blood levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), and total testosterone) were not observed. The mean calculated daily boron exposure (DBE) of the highly exposed group was 14.45 +/- 6.57 (3.32-35.62) mg/day. These human exposures represent worst-case exposure conditions to boric acid/borates in Turkey. These exposure levels are considerably lower than exposures, which have previously led to reproductive effects in experimental animals. ...

/HUMAN EXPOSURE 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.

LC50; Species: Oncorhynchus mykiss (Rainbow trout); Concentration: 100 ppm for 96 hr (soft water); exposure was initiated subsequent to fertilization and maintained through 4 days posthatching /Conditions of bioassay not specified in source examined/

LC50; Species: Oncorhynchus mykiss (Rainbow trout); Concentration: 79 ppm for 96 hr (hard water); exposure was initiated subsequent to fertilization and maintained through 4 days posthatching /Conditions of bioassay not specified in source examined/

LC50; Species: Ictalurus punctatus (Channel catfish); Concentration: 155 ppm for 96 hr (soft water); exposure was initiated subsequent to fertilization and maintained through 4 days posthatching /Conditions of bioassay not specified in source examined/

LC50; Species: Ictalurus punctatus (Channel catfish); Concentration: 22 ppm for 96 hr (hard water); exposure was initiated subsequent to fertilization and maintained through 4 days posthatching /Conditions of bioassay not specified in source examined/

For more Ecotoxicity Values (Complete) data for BORIC ACID (46 total), please visit the HSDB record page.

/AQUATIC SPECIES/ As a contribution to the investigation of properties of macrophytic water plants as bio-indicators the submerged softwater-macrophytes Myriophyllum alterniflorum, Ranunculus penicillatus and Elodea canadensis were polluted in an aquarium system with oligotrophic, Ca-poor water up to 4 wk with increasing concentrations of /boron/ (B) (H3BO3-/boric acid/) and with different compounds of B. The effect of the test substances was measured as a change of the net photosynthesis. Low B concentrations up to 2 mg B/L, which can be found in highly polluted waters, had only a small negative effect on R. penicillatus and E. canadensis. Stronger damages occurred with 5 mg B/l on M. alterniflorum and with 10 mg/L on the other 2 spp. The toxicity of different B compounds to E. canadensis at 2 mg B/L increased from boric acid and perborate to metaborate and borax. Boron trioxide had no negative influence after 21 test days in comparison with the control. Ecophysiological tests demonstrated that M. alterniflorum is a highly competitive species in oligotrophic softwater. The opinion of B as an environmental hazard has to be revised. At least in softwater systems, B had a much higher toxicity than formerly assumed.

/AQUATIC SPECIES/ A static renewal procedure, with batch-wise replacement of test and control solutions at regular intervals...was... /conducted using Daphnia magna/. ... There were 4 replicates for each test concentration and the control, resulting in 5 daphnids per replicate or a total of 20 organisms per concentration. ...The chronic study began by placing one neonate in each tube, where the daphnid remained for the entire study. Each Monday, Wednesday, and Friday the young produced by each adult were counted and discarded, and adult survival was recorded. In addition, on the same days, the dissolved oxygen, pH, and temperature in each test concentration and the control were measured and recorded. After enumeration of the young, the adults were transferred to clean beakers containing fresh test and control solutions, in addition to a new supply of food. The boric acid test concentrations used for the chronic test were 7, 14, 28, 56, and 105 mg/L as boron. ...The mean boron concentration was 0, 6.4, 13.6, 29.4, and 59.3 at 0, 7, 14, 28, and 56 mg/L, respectively. ...Throughout the chronic test the dissolved oxygen and temperature ranged from 7.3-8.0 mg/L and 19.5-20.5 °C, respectively. Mortality during the 21-day test was 0, 0, 10, 5, and 40% at 0, 7, 14, 28, and 56 mg/L, respectively. /No/... daphnids exposed to the highest concentration of boric acid (105 mg/L as boron) ... survived to reproductive age. Time to first reproduction was not affected by the test concentrations. The mean number of broods per daphnid, mean total young per daphnid, mean brood size per daphnid, and mean size all differed significantly from control at 13.6 mg/L. It appeared that the most biologically, as well as statistically, important endpoints for this study were those associated with reproduction and growth. Therefore, determination of the /maximum acceptable toxicant concentration/ (MATC) was based on the endpoints of mean total young per replicate, mean brood size, and mean size. The MATC of boric acid was estimated to lie between 6.4 and 13.6 mg/L as boron.

/AQUATIC SPECIES/ Static 96-hr exposures /of Oncorhynchus tshawytscha (Chinook salmon) and Oncorhynchus kisutch (Coho salmon)/ were conducted in 19.6-L glass jars containing 15 L of test solution /of boric acid/ and maintained at 12 +/-1 °C in temperature-controlled water baths. Each test consisted of exposing groups of 10 fish to a series of toxicant concentrations that differed by 60% between treatments, and a control. For large, advanced fry, duplicate sets of jars were used and only 5 fish were stocked in each jar to maintain loading densities of 0.8 g/L or lower. Observations of mortality and abnormal behavioral responses were made at 24-hour intervals, and all dead fish were removed after each observation. In 1 set of tests, 2 life stages of Chinook salmon and Coho salmon were tested with boric acid. One life stage composed of swim-up fry 8-12 weeks old (post hatch) tested in fresh water. The 2nd life stage composed of advanced fry 15-21 weeks old tested in brackish water. Chinook salmon were also tested in soft water. In tests conducted in the 2 site-specific waters, pH was measured at the beginning and end of the test. Eyed eggs, alevins, and swim-up fry of Chinook salmon were tested in soft water to determine the relative sensitivity of those various life stages to boron. ...Groups of 25 eggs, 10 alevins, or 10 swim-up fry were exposed to a series of toxicant concentrations that differed by 56% between treatments, and a control. Criteria of death for eggs were the presence of an opaque (whitened) membrane. Alevins were examined under 30x magnification for the absence of a heartbeat, which was the criterion for death. The 24-hr LC50 of Chinook and Coho salmon (fresh or brackish water) was >1000 mg/L. Boron was relatively non-toxic. Young Coho salmon tested in fresh water were less tolerant than older fish tested in brackish water and Chinook salmon tested in either dilution water. The relative sensitivity of various early life stages of Chinook salmon to boron changed significantly as the fish developed. Fry were consistently more sensitive than either the embryos or alevins to boron. The pH in test concentrations and controls were not markedly different, ranging from 6.5 to 8.1. No significant differences in 96-hr LC50 values were found among dilution water qualities, thus indicating that differences in water quality characteristics tested did not modify the toxicity of these chemicals.

/AQUATIC SPECIES/ /Water flea/ screening test was performed for 48-hours /in which Ceriodaphnia dubia were exposed/ to nominal concentrations of 0, 0.10, 1, 10, 100, and 1000 mg/L /boric acid, purity >99%/. At the end of the test there was 0% survival at 1000 mg/L, 10% survival at 100 mg/L, and 100% survival at all lower concentrations. ...Water quality parameters were within acceptable limits throughout the study. Dissolved oxygen concentrations were always above 7.8 mg/L. During the test, the mean temperature was 24.4 °C, the mean conductivity was 350 umhos/cm, and the pH ranged from 7.1 to 8.3. Hardness ranged from 88 to 100 mg/L in control vessels and from 88 to 108 mg/L in vessels containing 100 mg/L of the test substance. Alkalinity ranged from 16 to 21 mg/L in control vessels and from 16 to 23 mg/L in vessels containing 100 mg/L of the test substance. The percentage of surviving adults was not significantly reduced at any tested concentration, and sublethal effects were not observed at any concentration. The mean number of young per surviving adult was significantly lower than the control at the 3 highest tested concentrations (25, 50, and 100 mg/L). The most sensitive biological endpoint was production of young. The NOEC, LOEC, and MATC were 12.5, 25, and 17.7 mg/L, respectively.

For more Ecotoxicity Excerpts (Complete) data for BORIC ACID (12 total), please visit the HSDB record page.

Boric acid is found in nature as the mineral sassolite and is the predominant form of boron in natural waters. Atmospheric emissions of boric acid in particulate and vapor form occur as a result of volatilization of boric acid from the sea and volcanic activity; seawater evaporation is the biggest contribution in air. Boric acid's production and use in a wide variety of consumer and commercial products and applications may result in its release to the environment through various waste streams. It's use as a crosslinking agent and friction reducer in hydraulic fracturing fluids and its use as an active registered pesticide will result in its direct release to the environment. Atmospheric emissions of boric acid occur as a result of mining operations, glass and ceramics manufacturing, the application of agricultural chemicals, and coal-fired power plants. If released to air, a vapor pressure of 1.6X10-6 mm Hg at 25 °C indicates boric acid will exist in both the vapor and particulate phases in the atmosphere. Vapor-phase boric acid will be degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals; the half-life for this reaction in air is estimated to be about 38 days. Particulate-phase boric acid will be removed from the atmosphere by wet or dry deposition. If released to soil, the pKa of boric acid, 9.24 at 25 deg, indicates this compound will exist primarily in the undissociated form at an environmental pH range between pH 5 and pH 9, although the anion form will partially exist in alkaline soils(SRC). Adsorption of boron in soils depends on pH, organic content and types of clay and minerals in the soil. At acidic pH, boron exists in solutions in the form of undissociated boric acid; at alkaline pH, presence of borate ion occurs, which reaches maximum adsorption at pH 8.5-9. Field studies have observed boron to leach readily in soil; undissociated boric acid is transported in soil with little adsorption. Volatilization of boric acid from moist soil surfaces is not expected to be an important fate process given an estimated Henry's Law constant of 2.6X10-12 atm-cu m/mole, based upon its vapor pressure, 1.6X10-6 mm Hg, and water solubility, 5X10+4 mg/L. Boric acid is not expected to volatilize from dry soil surfaces based upon its vapor pressure. No biotransformation processes have been reported for boron compounds, including boric acid. If released into water, boric acid is not expected to adsorb to suspended solids and sediment based upon its observed leaching in soil. Volatilization from water surfaces is not expected to be an important fate process based upon this compound's estimated Henry's Law constant. However, evaporation of seawater itself is reported to be the biggest environmental contribution of boric acid to air. Occupational exposures to boron compounds (including boric acid) occurs through inhalation of dusts and dermal absorption. The general population is exposed to boric acid in various cosmetic products, including make-up, skin and hair care preparations, deodorants, moisturizing creams, breath fresheners, and shaving creams. (SRC)

Boric acid is found in nature as the mineral sassolite and is also the predominant form of boron in natural waters and an important form in biological systems(1). Atmospheric emissions of borates and boric acid in particulate (<1-45 um in size) or vapor form occur as a result of volatilization of boric acid from the sea and volcanic activity(2); seawater evaporation is the biggest contribution to boron in air(2).

Boric acid's production and use in a wide variety of consumer and commercial products and applications(1) may result in its release to the environment through various waste streams(SRC). Boric acid's use as a crosslinking agent and friction reducer in hydraulic fracturing fluids(2,3) and its use as an active registered pesticide(4) will result in its direct release to the environment(SRC). Atmospheric emissions of boric acid in particulate and vapor form occur as a result of mining operations, glass and ceramics manufacturing, the application of agricultural chemicals, and coal-fired power plants(1).

TERRESTRIAL FATE: The pKa of boric acid is 9.24 at 25 °C(1), indicating that this compound will exist primarily in the undissociated form at an environmental pH range between pH 5 and pH 9, although the anion form will partially exist in alkaline soils(SRC). Adsorption of boron in soils depends on pH, organic content and types of clay and minerals in the soil(1). At acidic pH, boron exists in solutions in the form of undissociated boric acid; at alkaline pH, presence of borate ion occurs, which reaches maximum adsorption at pH 8.5-9(2). Field studies have observed boron to leach readily in soil(1); undissociated boric acid is transported in soil with little adsorption(2). Volatilization of boric acid from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 2.6X10-12 atm-cu m/mole(SRC), based upon its vapor pressure, 1.6X10-6 mm Hg(3), and water solubility, 5X10+4 mg/L(4). Boric acid is not expected to volatilize from dry soil surfaces(SRC) based upon its vapor pressure. No biotransformation processes have been reported for boron compounds, including boric acid(2).

AQUATIC FATE: The pKa of boric acid is 9.24 at 25 °C(1), indicating that this compound will exist primarily in the undissociated form at an environmental pH range between 5 and 9, although the anion form will partially exist in alkaline waters(SRC). Boric acid leaches readily in soils(2) which indicates adsorption to suspended solids and sediment in water will not be an important fate process(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 2.6X10-12 atm-cu m/mole(SRC), derived from its vapor pressure, 1.6X10-6 mm Hg(4), and water solubility, 5X10+4 mg/L(5). However, evaporation of seawater itself is reported to be the biggest environmental contribution of boric acid to air(2). No biotransformation processes have been reported for boron compounds, including boric acid(2).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), boric acid, which has a vapor pressure of 1.6X10-6 mm Hg at 25 °C(2), will exist in both the vapor and particulate phases in the ambient atmosphere. One monitoring study found that approximately 90% of boric acid in the atmosphere is in gaseous form and 10% in particulate form(3). Vapor-phase boric acid is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be about 38 days(SRC), calculated from its rate constant of 4.2X10-13 cu cm/molecule-sec at 25 °C(SRC) that was derived using a structure estimation method(4). Particulate-phase boric acid may be removed from the air by wet or dry deposition(SRC).

No biotransformation processes have been reported for boron compounds(1). Boric acid has been shown to be a mild antiseptic agent with bacteriostatic action(2). A concentration beyond 10 mg/L produces toxicity to activated sludge cultures(3).

In aqueous solution, boron is normally present as boric acid and borate ions, with the dominant form of inorganic boron as undissociated boric acid in natural aqueous systems(1). In aqueous solution, boric acid acts as an electron acceptor (Lewis acid), accepting hydroxide from water to form (B(OH)4)- ion(1). In concentrated solutions (>0.1 M boric acid) polymeric species are formed(1,2). Photodegradation of boric acid is not a relevant environmental fate process(3).

The rate constant for the vapor-phase reaction of boric acid with photochemically-produced hydroxyl radicals has been estimated as 4.2X10-13 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method. This corresponds to an atmospheric half-life of about 38 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1).

Highly water soluble materials are unlikely to bioaccumulate to any significant degree, and borate species are all present essentially as undissociated boric acid at neutral pH(1). The octanol/water partition coefficient for boric acid has been measured as 0.175(1), indicating low bioaccumulation potential(1). Boron did not bioaccumulate in 47-day and 21-day exposure tests using oysters and sockeye salmon respectively(1).

Boric acid adsorption to illite (three-layered clay consisting of two outer layers of hydrated SiO2 and a central layer of hydrated Al2O3) and kaolinite (alternate layers of SiO2 and Al2O3) clays, as well as activated sludge was studied. The compound was added to 100 mL flasks corresponding to a boron concentration range of zero to 256 mg/L. It was observed that kaollinite adsorbed about 40 times (Kd = 0.199 (Freundlich adsorption coefficient)) more boric acid than illinite (Kd = 0.005) at pH 7; five times as much boric acid adsorbed to activated sludge (Kd = 0.025) as to illinite at pH 7(1). Boron adsorption is influenced by the distribution of boron species (H3BO3; B(OH)4(-)) as well as pH, the type and/or composition of the solution matrix, and surface properties(2). The pKa of boric acid is 9.24(3), indicating that this compound will exist primarily in the undissociated form in the environment, but partially in the anion form in alkaline soils(SRC). However, boric acid is a Lewis acid and therefore behaves as an electron acceptor, rather than a proton donor(3).

Adsorption of boron in soils depends on pH, organic content and types of clay and minerals in the soil(1). At acidic pH, boron exists in solutions in the form of undissociated boric acid; at alkaline pH, presence of borate ion occurs, which reaches maximum adsorption at pH 8.5-9(1). Field studies have observed boron to leach readily in soil(1).

The Henry's Law constant for boric acid is estimated as 2.6X10-12 atm-cu m/mole(SRC) derived from its vapor pressure, 1.6X10-6 mm Hg(1), and water solubility, 5X10+4 mg/L(2). This Henry's Law constant indicates that boric acid is expected to be essentially nonvolatile from water surfaces(3). Boric acid is not expected to volatilize from dry soil surfaces based upon its vapor pressure(SRC).

DRINKING WATER: The concentration of boron in tap water ranges from 7 ppb to 0.2 ppm(1).

SURFACE WATER: A worldwide average concentration of boron in fresh river water is reported to be 13 ppb(1).

SEAWATER: A worldwide average concentration of boron in seawater is reported to be about 5 mg/L(1).

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).

RURAL/REMOTE: Atmospheric concentrations of boron were measured at continental, coastal, and remote marine sites(1); mean particulate boron concentrations ranged from 1.8 to 12.2 ng/cu m, from 2.4 to 3.7 ng/cu m, and from <0.5 to 2.8 ng/cu m for the three types of site, respectively; mean gaseous boron concentrations ranged from <0.5 to 20.7 ng/cu m, from 3.5 to 82.8 ng/cu m, and from 0.6 to 25 ng/cu m, respectively(1).

According to the 2006 TSCA Inventory Update Reporting data, the number of persons reasonably likely to be exposed in the industrial manufacturing, processing, and use of boric acid is 100 to 999; the data may be greatly underestimated(1).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 489,668 workers (211,838 of these are female) are potentially exposed to boric acid in the US(1). Occupational exposures to boron compounds (including boric acid) occurs through inhalation of dusts and dermal absorption(2). A mean boric acid/boric oxide dust concentration of 4.1 mg/cu m has been reported in a boric acid manufacturing plant(2). The general population may be exposed to boric acid through use of various consumer products containing this compound(SRC). Sodium borate and boric acid are used in various cosmetic products, including make-up, skin and hair care preparations, deodorants, moisturizing creams, breath fresheners, and shaving creams; concentrations may be up to 5%(2).

The products registered for use which contain boric acid as the active ingredient are applied in aquatic, outdoor and indoor sites (i.e., commercial, industrial, domestic dwellings, food handling establishments, sewage systems, wood protection treatment to buildings, etc). Depending on the use site, boric acid may be applied using a spreader, fixed-wing aircraft, knife/spatula, airblower, power duster, squeeze applicator, or aerosol can. Based on the use patterns, the potential for dermal and inhalation exposure exists, (i.e., exposure to persons applying the products, exposure to humans reentering the treated areas, etc)(1).

In serum (children): Conventional reference range: < 7 mg/L; international recommended reference range: < 119 umol/L /From table, borate/

In serum (male adult): Conventional reference range: < 2 mg/L; international recommended reference range: < 34 umol/L /From table, borate/

In serum (toxic concn): Conventional reference range: > 20 mg/L; international recommended reference range: > 340 umol/L /From table, borate/

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.

R: 60-61; S: 53-45; Symbol: T