Hazardous assessment - steps 4 to 7

Step 4 - determine the chemical composition

In order to assess whether your waste has a hazardous property, you will need to know its composition. Information is available from a number of sources:

• Risk/COSHH assessments should contain detail on substances and products used and expected outcomes;
• For products which are unchanged, the manufacturer's safety data sheet; or
• Sampling or analysis can be used to determine composition.

All reasonable efforts should be undertaken to determine the composition of the waste. In the case of mirror entry wastes, where the composition is unknown and cannot be determined, the worse case scenario should be assumed. In this instance, it must be assumed that the waste is hazardous.

Step 5 - identify if the substance is hazardous

Once the chemical composition has been identified, it is necessary to check if any substances present are classified as hazardous or as 'persistent organic pollutants'. See here for further detail on assessing whether substances are hazardous.

Step 6 - assess the hazardous properties

All hazardous properties (HP1 to HP15) must be considered.

There are three methods which can be used:

• Calculation - use the concentration limit for a hazard statement code;
• Testing to prove whether a particular hazardous property is present or not; or
• The safety data sheet - to be used where the waste is a manufactured product whose composition has not changed.

Once you know what substances are present (or have assumed the worst case scenario), you will be able to determine which hazard statement codes are involved. The hazard statement codes determine which hazard properties need to be considered.

Table 2.1 in WM3 (P11 - 15) shows which hazardous properties are associated with each hazard statement code and, where appropriate, indicates the concentration limit. This table is linked below.

For information on how to assess further within each hazard category, see Appendix C of WM3.

Step 7 - assign the code and describe the properties

At this stage, you should refer back to your classification.

1. If your waste is classified as an 'absolute hazardous entry', the waste is definitely hazardous and you must dispose of it accordingly.
2. If your waste is classified as an 'absolute non-hazardous entry', the waste is not-hazardous and you must dispose of it accordingly. However, if a waste is described by a 'non-hazardous' code but still displays a hazardous property, it must be assessed using Steps 4 to 6 above to confirm.
3. If your waste is 'mirror hazardous' or 'mirror non-hazardous' then:
   • If the waste displays a hazardous property or contains POPs above the specified concentration then it use the 'mirror hazardous' EWC code, and dispose of as hazardous waste.
   • If the waste does not display a hazardous property and does not contain POPs, the 'mirror non-hazardous' code can be assigned.

Disposal

Once you have your EWC code and know whether your waste is hazardous, refer to the relevant section for disposal or contact the Waste Office for clarification.