Calculator Inputs
The result appears above this form after submission.
Example Data Table
This example shows one modeled scenario using the same equations built into the calculator.
| Compound | Measured Concentration | Toxic Threshold | Accumulation Factor | Adjusted Exposure | Toxicity Index | Risk Band |
|---|---|---|---|---|---|---|
| Example Compound | 10.00 mg/L | 20.00 mg/L | 2.3493 | 14.69 mg/L | 98.66 | Elevated |
Formula Used
This model combines concentration, protein binding, repeated exposure, organ function, duration, and dose load into one comparable toxicity score.
- Free Fraction = 1 − Protein Binding / 100
- k = ln(2) / Half-life
- Accumulation Factor = 1 / (1 − e^(−k × Dosing Interval))
- Clearance Adjustment = 100 / Average Organ Function
- Duration Factor = 1 + min(Exposure Days / 14, 1.5)
- Dose Factor = 1 + (Daily Dose / Body Weight) / 25
- Adjusted Exposure = Concentration × Free Fraction × Accumulation Factor × Clearance Adjustment × Bioavailability Factor × Sensitivity Factor × Duration Factor
- Toxicity Index = (Adjusted Exposure / Toxic Threshold) × 100 × Dose Factor
How to Use This Calculator
- Enter the compound name for easier reporting.
- Provide measured concentration, therapeutic upper limit, and toxic threshold in the same unit system.
- Fill in half-life and dosing interval to estimate repeated exposure accumulation.
- Enter daily dose and body weight to scale the dose burden.
- Add protein binding and bioavailability to reflect active circulating exposure.
- Set renal and hepatic function as percentages of normal clearance.
- Choose exposure duration and sensitivity factor for scenario stress testing.
- Press Calculate Toxicity to display the result above the form.
- Use the CSV or PDF buttons to export the generated report.
Frequently Asked Questions
1. What does the toxicity index mean?
The toxicity index is a comparative score. It combines measured concentration with modeled accumulation, clearance reduction, exposure duration, and dose burden. Higher values indicate a more concerning exposure profile relative to the toxic threshold.
2. Is this calculator intended for medical treatment decisions?
No. It is an educational chemistry and pharmacokinetic-style comparison tool. It should not replace poison control guidance, physician judgment, therapeutic drug monitoring protocols, or emergency assessment.
3. Why is protein binding included?
Protein binding reduces the immediately free fraction of a compound in circulation. Lower binding usually increases the available active portion, which can raise adjusted exposure and the modeled toxicity index.
4. How does the accumulation factor work?
The accumulation factor grows when dosing intervals are short relative to half-life. That means the compound is modeled to stack between doses instead of clearing fully before the next exposure cycle.
5. What do renal and hepatic percentages represent?
They act as simplified organ-function modifiers. Lower percentages increase the clearance adjustment value, which raises modeled exposure because the compound is assumed to clear less efficiently.
6. Can I compare two compounds with this tool?
Yes. Run the calculator separately for each compound using consistent units and assumptions. Then compare toxicity index, adjusted exposure, threshold ratio, and safety margin across both reports.
7. Why can the safety margin become negative?
A negative safety margin means the modeled adjusted exposure is above the toxic threshold. In other words, the scenario exceeds the benchmark used by the calculator’s comparison method.
8. What units should I use?
Use one consistent concentration unit throughout the threshold and measured fields. The default labels use mg/L, while dose should remain mg/day and body weight should remain kilograms.