A fatal case of acute boric acid poisoning

Potential Toxicity of Boric Acid Powder Otic Insufflation

OBJECTIVE

Boric acid (BA) powder is commonly used to treat otologic conditions, such as mastoid bowl inflammation and chronic otitis externa. Exposure to 50 mg per day is thought to cause systemic toxicity in humans. Inflamed skin and mucosal surfaces readily absorb BA. The aim of this study was to measure the doses of BA commonly used in clinical otology and alert the otolaryngology community to BA's underappreciated potential source of systemic toxicity.

STUDY DESIGN

Prospective, controlled.

SETTING

Laboratory.

METHODS

BA dose administration was measured by weighing the BA generated by common insufflators: accordion bellows, House-Sheehy insufflator, DeVilbiss insufflator, and pneumatic powder blower. Manual insufflation was performed with 3 compressions of the bulb. The pneumatic blower was sprayed for 1 second. Measurements were repeated 10 times.

RESULTS

The DeVilbiss insufflator delivered the lowest mean BA dose, 6.1 mg (SD 3.4, range 2.1-13.7), followed by the House-Sheehy 8.9 mg (SD 8.4, range 1.6-27.8), the pneumatic blower 192.8 mg (SD 38.3, range 150.0-261.7), and the accordion, 284.1 mg (SD 215.0, range 37.8-730.8).

CONCLUSION

BA dose delivery is highly variable by insufflator type, and doses thought to cause systemic toxicity are commonly generated. Awareness of and further investigation into the potential toxicity of otic administration of BA seems warranted.

Toxicity of boric acid, borax and other boron containing compounds: A review

Boron, often in the form of boric acid, is widely used as a flame retardant in insulation products, and although humans ingest boron through food, high exposure may lead to unwanted health effects. We assessed the toxicity of boric acid, borax and other forms of boron, after inhalation, dermal and oral exposure. After oral exposure, boron is absorbed over the gastrointestinal tract. Intact skin seems to pose a more effective barrier to boron than compromised skin. Boron excretion seems to mainly occur via the urine, although after skin exposure boron has been demonstrated in bile and gastrointestinal contents. Inhalation toxicity data are sparse, but one animal study showed reduced foetal weight after inhalation of cellulose that had a boric acid content of 20%. Skin exposure to boric acid has proven fatal in some cases, and the range of toxicity effects include abdominal as well as local effects on the skin. Fatalities from boric acid also have occurred after oral ingestion, and the endpoints in animals are weight loss and reproductive toxicity. Concerning genotoxicity studies, the overall picture indicates that boron-containing compounds are not genotoxic. There was no evidence of the carcinogenicity of boric acid in a 2-year study in mice.

Theoretical Study on Ionization of Boric Acid in Aqueous Solution by Ab Initio and DFT Methods at T=298.15 K

Objectives

The aim of this research work was to theoretically calculate the pK_a value of boric acid in aqueous solution by theoretical methods at T=298.15 K.

Materials and Methods

Boric acid has antifungal and antiviral properties. It is used in various prescription pharmaceutical products. The ab initio and density functional theory (DFT) methods were used in this research work.

Results

To explain the determined acidic dissociation constant, the various molecular conformations and solute-solvent interactions of the species of boric acid were considered. The basis set at the B3LYP/6-31+G (d) level of theory was selected for DFT calculations. We analyzed the formation of intermolecular hydrogen bonds between several species of boric acid and water molecules through Tomasi's method.

Conclusion

The result showed that there was comparable agreement between the experimentally and theoretically determined pK_a values for boric acid.

Cardiac arrest induced by the intentional ingestion of boric acid and mirtazapine treated by percutaneous cardiopulmonary bypass: a case report

Background

Mirtazapine has a good tolerability and safety profile that demonstrates several benefits over other antidepressants and it is associated with few fatalities. Boric acid is an odorless white powder that is generally not recognized as a poisonous substance. We report a case of cardiac arrest induced by the intentional ingestion of mirtazapine, boric acid, and sennosides, by a patient who required percutaneous cardiopulmonary bypass.

Case presentation

Our patient was a 49-year-old Japanese woman with a history of depression; she was found in an unconscious state after ingesting boric acid (unknown amount), mirtazapine (1950 mg), and sennosides (780 mg). On arrival, she was in a deep coma with marked hypotension induced by atrial fibrillation, tachycardia, and diffuse hypokinetic cardiac motion. She had systemic diffuse erythema. Her serum concentrations of boric acid and mirtazapine on arrival were 560.49 mg/L and 1270 ng/mL, respectively. She experienced repeated cardiac arrest, and was therefore treated with tracheal intubation, mechanical ventilation, percutaneous cardiopulmonary bypass, and continuous hemodialysis filtration. Stable circulation and respiration and a normal kidney function were finally obtained and she was transferred to a local medical facility in a persistent unconscious state.

Conclusions

This is the first case of a return of spontaneous circulation after cardiac arrest induced by the intentional ingestion of boric acid and mirtazapine, requiring percutaneous cardiopulmonary bypass for survival. To maintain cerebral perfusion during percutaneous cardiopulmonary bypass, even in a prolonged state of cardiac arrest induced by overdose, is medically, ethically, and economically challenging.

Current data regarding the structure-toxicity relationship of boron-containing compounds

Boron is ubiquitous in nature, being an essential element of diverse cells. As a result, humans have had contact with boron containing compounds (BCCs) for a long time. During the 20th century, BCCs were developed as antiseptics, antibiotics, cosmetics and insecticides. Boric acid was freely used in the nosocomial environment as an antiseptic and sedative salt, leading to the death of patients and an important discovery about its critical toxicology for humans. Since then the many toxicological studies done in relation to BCCs have helped to establish the proper limits of their use. During the last 15 years, there has been a boom of research on the design and use of new, potent and efficient boron containing drugs, finding that the addition of boron to some known drugs increases their affinity and selectivity. This mini-review summarizes two aspects of BCCs: toxicological data found with experimental models, and the scarce but increasing data about the structure-activity relationship for toxicity and therapeutic use. As is the case with boron-free compounds, the biological activity of BCCs is related to their chemical structure. We discuss the use of new technology to discover potent and efficient BCCs for medicinal therapy by avoiding toxic effects.

Experimental and numerical analysis of metal leaching from fly ash-amended highway bases

A study was conducted to evaluate the leaching potential of unpaved road materials (URM) mixed with lime activated high carbon fly ashes and to evaluate groundwater impacts of barium, boron, copper, and zinc leaching. This objective was met by a combination of batch water leach tests, column leach tests, and computer modeling. The laboratory tests were conducted on soil alone, fly ash alone, and URM-fly ash-lime kiln dust mixtures. The results indicated that an increase in fly ash and lime content has significant effects on leaching behavior of heavy metals from URM-fly ash mixture. An increase in fly ash content and a decrease in lime content promoted leaching of Ba, B and Cu whereas Zn leaching was primarily affected by the fly ash content. Numerically predicted field metal concentrations were significantly lower than the peak metal concentrations obtained in laboratory column leach tests, and field concentrations decreased with time and distance due to dispersion in soil vadose zone.

Renal cortical necrosis complicating laundry detergent ingestion

Accidental oral detergent ingestion usually causes mild gastrointestinal manifestations including nausea, vomiting and diarrhea as well as upper airway irritation. There are a limited number of reported oral detergent ingestions leading to acute kidney injury, mainly due to rhabdomyolysis. We present an ultimately fatal case of laundry detergent ingestion leading to biopsy proven severe cortical necrosis and irreversible renal damage. Detergent ingestion was associated with widespread endothelial injury leading to a picture of thrombotic microangiopathy. Among the detergent ingredients ingested by the patient, sodium borate raised the highest concern as a potential toxin exacerbated further by severe hypovolaemia and consequent decrease in renal toxin excretion. As sodium borate is dialyzable, haemodialysis should be a consideration early after laundry detergent ingestion.

Ingestion of a denture cleanser: did it cause gastric perforation?

INTRODUCTION

Human ingestion of denture cleansers leading to gastric perforation has not previously been described.

CASE REPORT

A 27-year-old male ingested three denture cleanser tablets in water over two days in an attempt to cause a false negative result on a workplace urine drug screen. Seven days later he presented to an emergency department with a perforated gastric ulcer.

DISCUSSION

A literature review of cases and the chemistry of the components of his ingestion was conducted to determine the possible relationship between these events. Ingestion of intact fragments of the tablets would be likely to result in significant gastric toxicity, but ingestion of dissolved tablets would be unlikely to have caused his illness.

Boron and the Kidney

Boron, the fifth element in the periodic table, is ubiquitous in nature. It is present in food and in surface and ocean waters, and is frequently used in industrial, cosmetic, and medical settings. Exposure to boron and related compounds has been recently implicated as a potential cause of chronic kidney disease in Southeast Asia. This observation prompted the present review of the published data on the effects of acute and chronic exposure to boron on renal function and structure in human beings and in experimental animals.

Environmental boron contamination in waters of Hisarcik area in the Kutahya Province of Turkey

Our aim was to determine boron levels in waters of rich boron mine areas in Turkey. There is a naturally occurring high level of boron in the ground waters of some parts of Turkey. Our study area is Hisarcik village in the Kutahya Province of Turkey which has a large number of boron mines. Boron occurs in combined form, usually borax (Na2B4O7 x 10H2O) and colemanite (Ca2B6O11 x 5H2O). Water samples were collected from many springs in order to determine boron concentrations and the amount of boron that is exposed to 88 samples from the drinking water (tap water), 37 from ground water and 257 from stream or pond water (surface water). Urine samples taken from 42 residents in this area were analyzed for boron and compared with its levels in drinking waters. The inductively coupled plasma/mass spectrometry (ICP/MS) method was used for the analysis of boron concentrations. Water boron contents at differing locations of this area ranged from 2.05 to 29.00 mg B/l. Mean value of boron was 10.20+/-4.08 mg B/l. Total urinary boron excretion was ranged from 0.04 to 50.70 mg B/l and mean value was 8.30+/-10.91 mg B/l. Current information on sources, occurrence, pollution potential and toxicity of environmental boron is discussed.

Comparative toxicology of borates

Inorganic borates, including boric acid, Na, ammonium, K, and Zn borates generally display low acute toxicity orally, dermally, and by inhalation. They are either not irritant or mild skin and eye irritants. Exceptions owing to physiochemical properties do occur. Longer-term toxicological studies have been reported mainly on boric acid or borax where the properties are generally similar on an equivalent boron (B) basis. The critical effects in several species are male reproductive toxicity and developmental toxicity. The doses that cause these effects are far higher than any levels to which the human population could be exposed. Humans would need to consume daily some 3.3 g of boric acid (or 5.0 g borax) to ingest the same dose level as the lowest animal NOAEL. No effects on fertility were seen in a population of workers exposed to borates or to a population exposed to high environmental borate levels. There is remarkable similarity in the toxicological effects of boric acid and borax across different species. Other inorganic borates that simply dissociate to boric acid are expected to display similar toxicity, whereas those that do not dissociate simply to boric acid may display a different toxicological profile.

Hazard assessment of boric acid in toys

Boric acid (H3BO3) has been used in a wide variety of applications--medication, pesticides, and household products. Reports of child poisoning by H3BO3 were common in the clinical literature before 1975. However, a decline in its use as a bacteriostatic agent coupled with increased regulatory control has almost eliminated poisonings by accidental ingestion. Schedule I (Part I, Item 8) of the Hazardous Products Act of Canada, proclaimed in the late 1960s, followed in the wake of concerns about accidental poisoning and prohibits its use in toys. Since that time, scientific knowledge has increased and has led to a reevaluation of the hazard associated with H3BO3. A maximum tolerated dose (MTD) was sought for children in the most susceptible age range, with a view to determine a maximum acceptable concentration (MAC) in toys. The effects of H3BO3 in a variety of exposure scenarios were evaluated. Precedence was given to clinical data in humans, particularly children, since there is no suitable animal model of boric acid intoxication. An extensive search of the pediatric literature was conducted to find a no-observed-adverse-effect level (NOAEL) or a lowest-observed-adverse-effect level (LOAEL). An analysis of the pivotal study to the present assessment resulted in the application of an uncertainty factor of 100 to account for variations in sensitivity among children and for the use of a LOAEL. Based on a pediatric LOAEL of 300 mg/kg body wt, we derived a MTD of 3 mg H3BO3/ kg body wt and a MAC of 9.1 mg H3BO3/g of toy. These results compared favorably with calculations from other human and animal NOAELs/LOAELs.