Q1; The chlorinated hydrocarbons are carcinogenic compounds, which have induced the bile duct cancer of workers at printing plants in Japan in 2012. The chlorinated hydrocarbons have been heavily used as cleaning solvent. The atmospheric concentration may be reached at several thousand ppm at work place. By the way, tap water may be contaminated with the chlorinated hydrocarbons, which are unintentionally produced by a sterilization process by chlorine.
Let’s execute shemical risk assessment for ubiquitous chlorinated hydrocarbons of dichloromethane CH2Cl2 or chloroform CHCl3. Let’s make evaluation of Margin of Exposure MOE of dichloromethane CH2Cl2 or chloroform CHCl3.
To evaluate the MOE, we need the estimated amounts of exposure and threshold of safe (termed by “POD:point of departure”). Some organization opened the Initial risk assessment of these chemicals. Please, find the informative documents for executing the risk assessment of dichloromethane CH2Cl2 or chloroform CHCl3.
The procedure is described as follows
(1) Establish the scenario; assuming the situation and condition of intake the chemicals
(2) Estimate the amount of exposure. This is carried out by finding the informative documents, in which the exposure condition is similar to the scenario.
(3) Establish the POD. The confidence of evaluation of POD is enhanced as lowering the uncertainty factors. And, we should also find the effective assessment documents, in which the scenario is as same as possible.
(4) Calculate the MOE, and compare to the uncertainty factors UFs.
The Q2 is the alternative question of Q1. You can choice whether Q1 or Q2.
Q2. Please, try to verify the reports of risk assessment presented by different organization. This comparative reviewing is also executed to your assessment Q1. Comment on the differences in confidence and usefulness by focusing on the scenario, assumption and methodology.
Make comments on the risks by comparison between MOE value and uncertainty factors UFs. Please, download the reports of risk assessment for the interested chemicals from a number of domestic and international organizations. In these reports, find out the amounts of exposure and criteria of safety. We can obtain the MOE value by the ratio of both values. We can download some reports of risk assessments for the same compound. Make comments on the reasons for different results. It should be easy to analyze the reports focusing on scenario, assumption, methodology.
Risk Assessment of Chemical Substances