Two Generation Reproduction Inhalation Toxicity Study in rats/MnCl2/OECD 416/Oral/GLP
This study was conducted under a worker’s safety programme to ascertain if exposure to any manganese base substance could lead to a disruption in reproductive performance of workers. As first steps, a literature review of all available published literature dating back 50 years
produced equivocal results. It was therefore important to understand and be clear on the reprotoxicity potential any potential reprotoxic effects which could occur upon the exposure to manganese based substances. Manganese dichloride is a water soluble and readily
bioavailable manganese specie.
The objective of this study was to provide general information concerning the effects of manganese dichloride on reproductive performance in rats. F0 animals were randomised into 3 test groups exposed to 5, 10 and 20 μg/L and one control group (air only), each containing 28 males and 28 females. These animals were dosed for 10 weeks prior to mating, and then throughout mating, gestation and lactation until termination after the F1 generation had reached Day 21 of lactation. From each treatment group, at least 24 males and 24 females were retained for post weaning
assessments. These animals continued on study and were dosed for approximately 11 weeks after weaning, and throughout mating, gestation and lactation until termination after the F2 generation had reached Day 21 of lactation.This study is designed to fulfil the objectives of OECD guideline 416 and US EPA Guideline OPPTS 870.3800.
Under the conditions of this study, a No Observed Effect Level (NOEL) for adult effects was not established due to effects on the respiratory tract. However, the respiratory tract effects observed are commonly observed in irritant materials and were
considered not to be a unique effect of manganese dichloride and therefore, when the local irritant effects are disregarded; the parental No Observed Adverse Effect Level (NOAEL) was
considered to be target level 20 μg/L. The No Observed Effect Level (NOEL) for reproductive performance was considered to be target dose level 20 μg/L.
Other relevant information
- The study has also been published in peer-review literature: D. McGough, L. Jardine (2017) A two-generation inhalation reproductive toxicity study upon the exposure to manganese chloride. Journal of Neurotoxicology, Vol 58. http://www.sciencedirect.com/science/article/pii/S0161813X16301978
- This study is one of the main supporting studies used by the Texas Commission on Environmental Quality (TCEQ) for the derivation of permissible air quality concentrations for inorganic Manganese