SDSRP Practice - Rubric 7 Risk Analysis

Risk

The potential that injury will occur in a given exposure situation

or

The probability that adverse effects will occur in a given exposure situation

Hazards

The intrinsic properties of these chemicals or mixtures. Introduces exposure to the risk formula.

Risk-Based Product Labeling

Can only be applied by competent authorities to the chronic health hazards of chemicals in the consumer product setting.

Risk Analysis

The process of “estimating” the risk of adverse health effects under a particular exposure scenario

Risk Assessment

A function of two variables:

1) Toxicity (Hazard)

2) Exposure

Formula: Risk = Toxicity * Exposure

Toxicity (Hazard)

The ability of a chemical, physical, or biological agent to cause damage to biologic material (i.e. to cause adverse health effects)

• Is an inherent property of all chemicals

• Can’t be altered or eliminated

• Chemicals can (and often do) have more than one

Hazard-Based Assessment

The GHS is based on this type of assessment, in which exposure is not taken into consideration.

Risk-Based Assessment

Exposure is taken into consideration in this assessment type

Exposure

The amount of a chemical, physical, or biological agent that is available for absorption into the body.

Exposure Elimination

Methods to reduce exposure:

1) Substitution of a toxic chemical for one having a “lesser” relative toxicity

2) Use of appropriate ventilation (passive or active)

3) Use of appropriate personal protective equipment

4-Step Risk Assessment

1) Hazard identification

2) Dose-Response assessment

3) Exposure assessment

4) Risk characterization

Hazard Identification

The process of determining whether an agent can cause an adverse health effect(s)

Dose-Response Assessment

The process of characterizing the quantitative relationship between the dose of an agent and the resulting adverse health effect

Dose-Response Assessment: Non-Carcinogens

Derive an Acceptable Daily Intake (ADI):

ADI = NOAEL/SF (safety factor)

Safety Factor

A unitless number that accounts for uncertainties in extrapolation of results from toxicity tests carried out in experimental animals to humans.

Dose-Response Assessment: Carcinogens

Derive the Unit Risk (or CSF or CPF)

• Units are 1/(mg/kg-day)

Unit Risk (or Cancer Slope Factor/Cancer Potency Factor)

1) Linear extrapolation using the linearized multistage model

2) Or computer models for low-dose extrapolation

• This assumes “linearity” in the low dose region of the carcinogen dose-response curve

Exposure Assessment

The process of quantifying (or estimating) the human intake of a chemical agent. Critical aspect of any risk assessment

Exposure Assessment: Non-Carcinogens

Assume the product is used in one day and 100% absorption of any hazardous components (very conservative assumptions)

Exposure Assessment: Carcinogens

Assumes lifetime (70 year) exposure and exposure is averaged over this period, even though the actual exposure may occur during only a segment of this period

Risk Characterization: Non-Carcinogens vs Carcinogens

Non-Carcinogens: Compare the ADI (mg/kg-day) with the estimated human exposure (mg/kg-day): It is preferred for the estimated human exposure value to be less than the ADI

Carcinogens:

Risk = Toxicity * Exposure

Risk = 0.5 mg/kg-day * 0.0006 mg/kg-day

Risk = 0.0003

Risk Characterization

Determining if the agent is within the limits for “acceptable” risk

Risk Characterization: Labeling

Labeling for consumer products is risk based