Is Boric Acid Toxic to Reproduction in Humans? Assessment of the Animal Reproductive Toxicity Data and Epidemiological Study Results.
Boric acid and sodium borates are classified as toxic to reproduction in the CLP Regulation under "Category 1B" with the hazard statement of "H360FD". This classification is based on the reprotoxic effects of boric acid and sodium borates in animal experiments at high doses. However, boron mediated reprotoxic effects have not been proven in epidemiological studies so far. The epidemiological study performed in Bandırma boric acid production plant is the most comprehensive published study in this field with 204 voluntarily participated male workers. Sperm quality parameters (sperm morphology, concentration and motility parameters), FSH, LH and testosterone levels were determined in all participated employees as the reproductive toxicity biomarkers of males. However, boron mediated unfavorable effects on reproduction in male workers have not been determined even in the workers under very high daily boron exposure (0.21 mg B/kg-bw/day) conditions. The NOAEL for rat reproductive toxicity is equivalent to a blood boron level of 2020 ng/g. This level is higher than the mean blood boron concentration (223.89 ± 69.49 ng/g) of the high exposure group workers in Bandırma boric acid production plant (Turkey) by a factor of 9. Accordingly, classifying boric acid and sodium borates under "Category 1B" as "presumed reproductive human toxicant in the CLP regulation seems scientifically not reasonable. The results of the epidemiological studies (including the study performed in China) support for a down-classification of boric acid from the category 1B, H360FD to category 2, H361d, (suspected of damaging the unborn child).
Ankara University, Faculty of Pharmacy, Department of Toxicology, 06100, Tandoğan, Ankara, Turkey. duydu@pharmacy.ankara.edu.tr.
Yalçın
Y
Duydu
Nurşen
N
Başaran
Aylin
A
Ustündağ
Sevtap
S
Aydın
Ulkü
U
Undeğer
Osman Yavuz
OY
Ataman
Kaan
K
Aydos
Yalçın
Y
Düker
Katja
K
Ickstadt
Brita Schulze
BS
Waltrup
Klaus
K
Golka
Hermann Maximilian
HM
Bolt
D000395:Air Pollutants, Occupational / Q000032:analysis / Q000633:toxicity*; D000818:Animals; D001888:Boric Acids / Q000633:toxicity*; D001895:Boron / Q000032:analysis / Q000097:blood / Q000652:urine; D060766:Drinking Water / Q000032:analysis; D005506:Food Contamination / Q000032:analysis; D006801:Humans; D008297:Male; D016273:Occupational Exposure / Q000009:adverse effects / Q000032:analysis; D051381:Rats; D012098:Reproduction / Q000187:drug effects*; D018570:Risk Assessment; D012661:Semen / Q000737:chemistry; D013081:Sperm Motility / Q000187:drug effects; D013094:Spermatozoa / Q000187:drug effects; D014421:Turkey / Q000453:epidemiology; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity
D000395:Air Pollutants, Occupational; D001888:Boric Acids; D060766:Drinking Water; D014874:Water Pollutants, Chemical; D001895:Boron; C032688:boric acid