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Ultratrace Minerals
Published in Luke R. Bucci, Nutrition Applied to Injury Rehabilitation and Sports Medicine, 2020
The most common boron compounds are boric acid and sodium borate (Na2B4O7̇10 H2O or borax). Boric acid and borates were widely used as food preservatives from the 1870s to the 1920s and greatly contributed to preventing even worse famines during World War I.1003 However, a study from the USDA in 1904 in which 500 mg B per day (as borax) was fed to humans reported disturbances in appetite and digestion.1003 This finding, coupled with known toxicity of borates when applied as an antibiotic to large areas of broken skin (from bums and open wounds), led to a worldwide ban on borates as a food preservative in the 1920s.1003 World War II saw a resurgence of boric acid used as a plentiful and inexpensive food preservative, as well as studies of effects of feeding large amounts of boron to animals, which exhibited toxicity. Once again, use of boron was banned in the 1950s.1003 Recently, boric acid powder has found widespread acceptance as a household insecticide.1004 In addition, the U.S. Department of the Interior has set an upper limit for boron in public water supplies at 1 μg/ml.1005
The Modification of Lysine
Published in Roger L. Lundblad, Chemical Reagents for Protein Modification, 2020
Mahley and co-workers49 used carbamylation to explore the role of lysyl residues in the binding of plasma lipoprotein to fibroblasts. The reaction was performed in 0.3 M sodium borate, pH 8.0. The extent of modification was determined in two ways. In the first, the modified protein was subjected to acid hydrolysis. The amount of homocitrulline, the product of the reaction of the ∊-amino group of lysine with cyanate, was considered equivalent to the number of lysine residues modified. However homocitrulline is partially degraded on acid hydrolysis to produce lysine (17 to 30%). In order to obviate this difficulty, these investigators removed a portion of the modified protein and reacted it under denaturing conditions with 2,4-dinitrifluorobenzene, yielding an acid-stable derivative. The number of lysine residues modified was therefore the sum of free lysine and homocitrulline obtained on amino acid analysis following acid hydrolysis.
Antiseptics *
Published in Bev-Lorraine True, Robert H. Dreisbach, Dreisbach’s HANDBOOK of POISONING, 2001
Bev-Lorraine True, Robert H. Dreisbach
Boric acid (H3BO3) is a white compound that is soluble to the extent of 5% in water at 20°C. Sodium borate, or borax (Na2B4O7·10H2O), is a white compound that is soluble to the extent of 14% in water at 55°C. Sodium perborate (NaBO3·4H2O) is a white compound that is slightly soluble in cold water and decomposes in hot water. Boron oxide is used in industry. Pentaborane, decaborane, and diborane are used as propellants.
Assessment of consumer exposure to boron in cleaning products: a case study of Canada
Published in Critical Reviews in Toxicology, 2021
Paul C. DeLeo, Sharon B. Stuard, Owen Kinsky, Christine Thiffault, Brittany Baisch
Boron-based ingredients, including boric acid, sodium perborate, and sodium borate (aka borax and sodium tetraborate decahydrate), are found in many consumer goods including household cleaning products such as all-purpose cleaners, laundry detergents, and stain removers (SDA 1998; HERA 2005; ATSDR 2010). Boric acid is added to liquid laundry detergents up to 2% concentration to stabilise the protease and other enzymes in the formulation (HERA 2005). Perborates have been used as non-chlorine bleaching agents in granular detergents (SDA 1998). In addition, sodium borate (sodium tetraborate decahydrate), which contains 11.3% boron, is recommended as a do-it-yourself cleaner around the home (Gibson and Turner 2015). Use of boron-containing ingredients in consumer products such as cleaning products has been the subject of regulatory concern because toxicity studies on boric acid and related compounds have demonstrated reproductive as well as developmental effects in animals at high doses (Ku et al. 1993; Murray 1995; EFSA ANS Panel 2013).
What can we learn from epidemiological studies on chronic boron exposure?
Published in Critical Reviews in Toxicology, 2023
Yalçın Duydu, Nurşen Başaran, Hermann M. Bolt
Regulatory concern has been focused on the reproductive toxicity of boron compounds. Experimental studies on male fertility in rats and mice revealed dose-dependent adverse effects on spermiation and sperm quality, and finally sterility (Weir and Fisher 1972; Linder et al. 1990; Fail et al. 1991; Ku et al. 1993; Bolt et al. 2020). A no observed adverse effect level (NOAEL) for fertility effects in Sprague-Dawley rats was identified as 17.5 mg B/kg-bw/day (Weir and Fisher 1972). As far as developmental toxicity is concerned, decreased mean fetal body weights, increased incidences of short rib XIII, and increased numbers of malformed fetuses have been reported in borate-treated female rats, mice, and rabbits (Heindel et al. 1992; Allen et al. 1996; Price et al. 1996a, 1996b; Fail et al. 1998). The NOAEL for such developmental effects in female Sprague-Dawley rats was identified as 9.6 mg B/kg-bw/day (Price et al. 1996a). These studies were the scientific basis of a classification of boric acid and sodium borates as being toxic to reproduction under “Category 1B” with the hazard statement of “H360FD” (May damage fertility. May damage the unborn child) according to the European CLP Regulation (European Regulation on Classification, Labelling and Packaging of substances and mixtures) in 2007. This classification triggered a series of epidemiological studies on the possibility of reproductive effects in boron-exposed humans (Chang et al. 2006; Xing et al. 2008; Robbins et al. 2008, 2010). Owing to the geographical locations of major boron deposits, such epidemiological studies were conducted in China, Türkiye, and Argentina. This review summarizes the results of these epidemiological studies.
Antigenotoxic potential of boron nitride nanotubes
Published in Nanotoxicology, 2018
Non-toxic effects have been found for boron or BNNTs in D. melanogaster. These non-toxic effects were detected using two different approaches. In a first instance, we measured alterations in the egg-to-adult viability, which is the classical approach. Secondly, we evaluated changes in the larval length, as indicative of a poor development. In none of the cases, relevant changes were observed for the tested parameters. Although no previous studies used Drosophila to test BNNTs effects, this organism has been recently used to detect boron effects. Thus, in the study of Sarıkaya et al. (2016), they found a slight decrease in viability, but only when very high concentrations (40 mg/mL) were used. Nevertheless, these concentrations are much higher than those used in our study. Although no other studies assessed the toxic effects of boron compounds in Drosophila, an old study reported that low doses of sodium borate in the diet, improved life span of Drosophila adults (Massie 1994), which could be associated with its antioxidants properties. In this way, boron compounds are non-toxic but can increase viability in certain circumstances. These in vivo results reflect the non-toxicity of BNNTs and overcome the deceptive results observed in vitro where interactions with some assays, like the MTT, were observed (Ciofani et al. 2010a). In spite of this lack of effects, boron and BNNTs-induced statistical significant changes in the expression of different genes such as Duox, Hml, Muc68D, and PPO2 at the higher concentrations tested (5 and 10 mM). Although we have not measure the protein levels, to make sure this change in mRNA was translated to proteins, this set of genes has proven to be a good indicator of the toxic effects of other nanomaterials such as copper oxide nanoparticles (Alaraby et al. 2016b).