The following guidance should be used when rinsing containers that previously contained hazardous waste or hazardous materials.
Under federal rules:
- If the container held hazardous waste (HW) and has been emptied (as defined in 40CFR261.7) the rinsate is only regulated if it shows a characteristic of HW (ignitability,
corrosivity, reactive, Toxicity Characteristic Leaching Procedure [TCLP] toxicity).
- If the container is rinsed with water, corrosivity and TCLP toxicity are possibilities. Corrosivity can be easily determined by checking the pH. If the container held a contaminant listed on the TCLP list (heavy metals and solvents listed below), sample analyses may be required to determine toxicity. It is generally more cost effective to consider the first rinsate from these containers as a hazardous waste and dispose of it as such. The waste to sanitary sewers guidance may come into play, however, as the regulations allow a certain amount of hazardous waste to be discharged into the municipal sanitary sewer system – with their approval. Contact the Director of Environmental Management for further information prior to disposal of any potential hazardous waste.
- If the container holds HW and has not been emptied, the rinsate is the same HW that
was in the container (diluting HW doesn't change its regulatory status).
- Every effort should be made to empty hazardous waste containers by consolidating them into a container of compatible waste or re-containerizing the waste in a smaller container. In extreme situations where it might be necessary to rinse a container that contains hazardous waste, the rinsate must be containerized and properly labeled as a hazardous waste.
- If the container held acute hazardous waste, it is not empty until it has been triple-
rinsed with a suitable liquid. The first three rinses are regulated as acute hazardous
waste and the rinsate must be captured, containerized, properly labeled and handled
as an acute hazardous waste. After that, the container is considered “empty” and additional
rinsate is only regulated if it shows a characteristic.
- The acute hazardous wastes are listed in the regulations, 40 CFR 261.33 as P-listed wastes. P-listed wastes are defined as a commercial chemical or off-specification product, residue remaining in a container of P-listed chemicals and spill residue from clean-up of P-listed material.
- If the material in the container when discarded did not qualify as HW, the rinsate
is only regulated if it shows a characteristic of HW (ignitable, corrosive, reactive
or listed toxic), regardless of whether the container had been emptied.
- An example of the above condition is rinsing a container with residue of solid sodium hydroxide or potassium hydroxide (not a hazardous waste) and the initial water rinsate fails the characteristic for D002, corrosivity.
Hazardous materials containers are not routinely required to be rinsed after the contents have been removed. If however, the container is to be re-used rather than discarded, rinsing may take place.
If the container has been emptied, the rinsate is only regulated if it shows a characteristic of hazardous waste as described in the first bullet under Hazardous Waste, above.