User:Shenghong Wang/Tris(2-chloroisopropyl) phosphate

Tris(2-chloroisopropyl) phosphate (TCPP)
Tris(2-chloroisopropyl) phosphate (TCPP) with CAS number: 13674-84-5 is an organophosphate with the formula C9H18Cl3O4P. Due to the lower persistence, TCPP is used as flame retardants to replace brominated flame retardants. It is mainly used in polyurethane foams.

Properties
TCPP is colorless liquid at room temperature. Its solubility in water is 1.6g/L and is soluble in most organic solvents. The log octanol-water partition coefficient (Log KOW), log octanol-air water partition coefficient (Log KOA) acquired from the U.S. EPA Comptox database are 2.33 and 8.85. Based on the partitioning properties, TCPP is most likely present in water.

Health Effects
Studies have shown that TCPP can be toxic, carcinogenic. Recent in vitro studies show that TCPP could induce cell toxicity at relatively high concentrations, while the concentration of TCPP exceeds 100 µM the cell survival rates drop significantly with the increase of the concentration. A previous animal experiment shows that TCPP has a moderate to low acute toxicity while the oral LD50 in rats reached 1017-4200 mg/(kg body weight)  and inhalation routes LC50 exceeding 4.6mg/liter Although not many experiment data are available for the carcinogenicity of TCPP, Lambert et al believe that it should be considered as carcinogenic based on a study which shows initial concern for the carcinogenicity and the structural similarity to TDCP and TCEP which are all carcinogenic compounds.

Environmental impact
While the health effects of TCPP are still being studied, it is confirmed that TCPP can persistent in the environment. The Stockholm Convention using Trophic magnification factor (TMF) > 1 or Biomagnification factor (BMF) > 1 as cut-offs. In other words, if a chemical with TMF > 1 or BMF>1, this chemical is regarded as a persistent chemical. The TMF of TCPP was calculated as 1.77, whereby, TCPP is a persistent chemical. Another study proved the bioaccumulative potential of TCPP in the rainbow trout with the BMF value of 0.81 ± 0.39 and the calculated half-life of  50.2 ± 19.3 days which is similar to BMF and half-life of Persistent Organic Pollutants regulated by the Stockholm Convention. Compared with the old Brominated flame retardants TCPP replaced with, it is more soluble in water. According to Reemtsma et al. 2016, TCPP should be considered as persistent and mobile organic chemicals (PMOCs). This means TCPP has the ability to go through global transport.

Human Exposure
While biomonitoring data are very limited for TCPP, some screening-level models are available to access the potential risk for TCPP. It is mentioned in Zhang et al (2014) that around 20 percent of TCPP exposure occurred near field and 80 percent of that occurred far field. Based on both experimentally collected data and the modeling result, dietary ingestion, water ingestion, and non-dietary ingestion can be the most important exposure pathways for the TCPP exposure.