Knowledge Check Solutions
1) Genotoxic carcinogenicity of the substance - This is the correct answer.
The procedure for extrapolation from high to low doses depend on whether or not the effects are carcinogenic. Carcinogenic effects are not considered to have a threshold dose and mathematical models are used to estimate the risk of carcinogenicity at very low doses. Noncarcinogenic effects are considered to have threshold doses and the margin of safety (MOS) is calculated.
2) Evidence is adequate to demonstrate potential carcinogenicity to humans, but not strongly enough to definitively classify as carcinogenic - This is the correct answer.
A substance is classified as likely to be carcinogenic to humans when evidence is adequate to demonstrate carcinogenic potential to humans but does not reach the weight of evidence for the descriptor Carcinogenic to Humans.
3) Linearized Multistage Model (LMS) - This is the correct answer.
EPA uses the Linearized Multistage Model (LMS) to conduct its cancer risk assessments, producing the q1* that is used to predict cancer risk at a specific dose.
4) Dividing the NOAEL by safety factors - This is the correct answer.
The ADI is calculated by dividing the NOAEL by safety factors.
5) Ensure they use the conversion method mandated or recommended by the regulatory agency most relevant to their efforts - This is the correct answer.
Toxicologists and risk assessors should check to ensure they use the approach mandated or recommended by the regulatory agency most relevant to their efforts.
6) Similarly to deriving the RfD, but with a potentially lower uncertainty factor - This is the correct answer.
The MRL is calculated much like the RfD, except that the uncertainty factors of 10 may be lower (1 or 3), based on scientific judgment.
1) Genotoxic carcinogenicity of the substance - This is the correct answer.
The procedure for extrapolation from high to low doses depend on whether or not the effects are carcinogenic. Carcinogenic effects are not considered to have a threshold dose and mathematical models are used to estimate the risk of carcinogenicity at very low doses. Noncarcinogenic effects are considered to have threshold doses and the margin of safety (MOS) is calculated.
2) Evidence is adequate to demonstrate potential carcinogenicity to humans, but not strongly enough to definitively classify as carcinogenic - This is the correct answer.
A substance is classified as likely to be carcinogenic to humans when evidence is adequate to demonstrate carcinogenic potential to humans but does not reach the weight of evidence for the descriptor Carcinogenic to Humans.
3) Linearized Multistage Model (LMS) - This is the correct answer.
EPA uses the Linearized Multistage Model (LMS) to conduct its cancer risk assessments, producing the q1* that is used to predict cancer risk at a specific dose.
4) Dividing the NOAEL by safety factors - This is the correct answer.
The ADI is calculated by dividing the NOAEL by safety factors.
5) Ensure they use the conversion method mandated or recommended by the regulatory agency most relevant to their efforts - This is the correct answer.
Toxicologists and risk assessors should check to ensure they use the approach mandated or recommended by the regulatory agency most relevant to their efforts.
6) Similarly to deriving the RfD, but with a potentially lower uncertainty factor - This is the correct answer.
The MRL is calculated much like the RfD, except that the uncertainty factors of 10 may be lower (1 or 3), based on scientific judgment.