Calculated Oral or Dermal Toxicity

In many cases, acute dermal and acute oral toxicity data is available for pure chemical compounds, but not for chemical or waste mixtures. The method of determining whether a waste mixture is a toxic hazardous waste is by its calculated oral or dermal LD₅₀¹ when it contains some, but not 100% pure chemical compounds. Calculate the oral or dermal LD₅₀ for a waste mixture containing one or more acutely toxic (oral or dermal) compounds, and then compare it to the thresholds for toxic oral or dermal hazardous waste. For the calculated oral or dermal toxicity, both acute oral or dermal LD₅₀ or the acute LD_LO may be used. Remember, when determining the calculated oral LD₅₀ use oral LD data; the same goes for dermal data.

%A _x is the weight percent of each component in the waste mixture and ^TA _X is the acute oral or dermal LD ₅₀ or the acute oral LD _LO of each component.

Inhalation Toxicity

The concentration of each material in the head space vapor shall be calculated using the following equation²:

C (in parts per million) is the concentration of material A in head space vapor, Q (in milligrams) is the quantity of material A in sampling syringe and MW (in milligrams per millimole) is the molecular weight of material A. Where an acute inhalation LC ₅₀ is not available, an LC ₅₀ measured for another time (t) may be converted to an eight-hour value with the following equation: Eight-hour LC ₅₀ = (t/8) x (t-hour LC ₅₀).

References

¹ 22 CCR Section 66261.24(c)

² 22 CCR Section 66261.24(b)