Step 5.4 Work out your environment hazard characteristics
To work out the environment characteristics your chemical does and does not have, you must know your environment exposure band (Step 5.3). The information you need to consider hazard characteristics varies depending on your introduction’s exposure band.
You must have permission to use information that you relied on to demonstrate the absence of hazard characteristics. If we ask you for the information that you relied on to categorise your introduction, you need to provide us with the detailed information, including full study reports, of the kind we specify in this step to demonstrate the absence of the hazard characteristics.
Hazard characteristics in environment hazard bands
A chemical has an environment hazard characteristic if the chemical can cause damage, harm or adverse effects to the environment. For example, a chemical that has the 'toxic to any aquatic life' hazard characteristic can cause toxic injury to an organism following short term aquatic exposure.
Environment hazard characteristics are split up into hazard bands. Hazard characteristics of most concern are in hazard band D, while those of lower concern are in hazard band A.
See links below to each of the hazard bands: D, C, B and A.
Our pages for environment hazard bands D, C, B and A describe hazard characteristics (eg toxic to any aquatic life and so on) in each hazard band and the information you need to have to prove your chemical does not have a particular hazard characteristic.
Information you need and hazard characteristics you need to consider
This varies depending on your introduction’s environment exposure band.
If your introduction is in a lower exposure band
Generally, in the lower exposure bands, where the level of exposure to the environment is relatively low, as a minimum you have to consider only a few hazard characteristics and you don’t need much information on them.
If your introduction is in a higher exposure band
In comparison, in higher exposure bands, where the level of exposure to the environment is higher, generally you’ll need to consider more hazard characteristics and need more information on them.
Information you need for lower indicative risk
You will need more hazard information to be able to get to lower indicative risk outcomes. Generally, within any given environment exposure band you need:
- less hazard information to get to medium to high risk
- more hazard information to get to low risk
- the most hazard information to get to very low risk
Where to start and when you can stop considering your chemical's hazard characteristics
Always start in the highest hazard band (hazard band D) and work your way down the hazard bands as far as you need to get to your outcome (that is, D, C then B then A).
You must consider each hazard characteristic in the hazard band you are in (unless there is a reason for you to stop sooner) - does your chemical have that hazard characteristic or not?
When you might not need to consider all of the hazard bands
- Because your introduction’s environment exposure band (which you worked out in step 5.3) doesn’t require it. For example, if your introduction’s environment exposure band is 2, you only need to consider the hazards in hazard band D to get to an indicative environment risk of either medium to high or low.
- Because the outcome for indicative environment risk that you are trying to get to doesn’t require it. For example, if your introduction’s environment exposure band is 3 and you want to get to an indicative environment risk of low, you only need to consider the hazard characteristics in environment hazard bands D and C.
In many cases, you’ll only need to consider hazard band D. But in other cases you might need to consider D, C, B and A because your introduction is in exposure band 3 or 4 and you are trying to get to very low indicative environment risk.
When you can stop working through your chemical’s environment hazard characteristics
Stop if you:
- determine that your chemical has a hazard characteristic in the hazard band (e.g. persistent, bioaccumulative and toxic - you are in hazard band D) or
- cannot demonstrate that your chemical does not have a certain hazard characteristic in that hazard band . This means that we consider your chemical to have this hazard characteristic or
- get to an indicative environment risk outcome and don’t want to go any further - see step 5.5 for more information about environment risk outcomes or
- have demonstrated that your chemical does not have any hazard characteristics in hazard bands D, C, B and A . This would only be needed for environment exposure bands 3 and 4. It means that the indicative environment risk of your introduction is very low
After you stop, you don’t need to consider the remaining hazard characteristics in the hazard band where you stopped, or any of the hazard characteristics in lower hazard bands. Take note of where and why you stopped and move on to step 5.5.
Example: Rosemary's introduction is in environment exposure band 4. She considers all of the hazard characteristics in environment hazard band D and can demonstrate that her chemical does not have any of these hazards. Rosemary then moves on to hazard band C. She works through the hazard characteristics in this hazard band in the order that they are shown in the table. When Rosemary comes to 'very toxic to any aquatic life', she finds that her chemical has this hazard characteristic. This means Rosemary can stop there. The indicative environment risk of Rosemary's introduction is medium to high. She does not need to continue further to see if her chemical has the other hazard characteristic in hazard band C (persistent and bio-accumulative). Also Rosemary doesn't need to consider if her chemical has any of the hazard characteristics in hazard bands B or A.
How to consider each hazard characteristic
Look at whether your chemical meets the hazard characteristic definition based on the information that you have.
If it does meet the hazard characteristic definition, stop there and move to step 5.5.
If it does not meet the hazard characteristic definition, you’ll need to try and prove that your chemical does not have this hazard characteristic.
Our pages on hazard bands D, C, B and A describe hazard characteristics and the ways to prove that your chemical does not have a hazard characteristic.
How to prove that your chemical does not have a hazard characteristic
You can read about your options to prove that your chemical does not have a particular hazard characteristic on each environment hazard band page. These options include:
- checking if your chemical is on the list of chemicals with high hazards for categorisation
- in silico predictions
- in vitro test results
- in vivo test results
- suitable read-across information in place of information on the chemical itself
- other information about your chemical that means that testing and in silico predictions are not necessary (that is, information waivers)
If you have access to existing information on the chemical or suitable read-across information, you should consider these first. If you need to generate new data to prove the absence of a hazard characteristic, you should choose non-animal test data when possible. You should only generate new animal test data as a last resort.
If you can prove that your chemical does not have the hazard characteristic, move on to the next hazard characteristic in that hazard band, or from the next hazard band down.
If you cannot prove that your chemical does not have the hazard characteristic, stop there – your chemical is considered to have this hazard characteristic.
Take note of the hazard band that this hazard characteristic is in. If your chemical is one of these:
there may be different requirements for you to prove that your chemical does not have certain hazard characteristics.
Resources to help you with this step
We refer to the following throughout this step:
- List of chemicals with high hazards for categorisation
- In silico information - an overview of which human health (4.4) and environment characteristics have in silico options and which in silico models are appropriate.
You can also check our glossary for the definition of in silico.
- Acceptable test guidelines for each environment hazard characteristic in this step
- Suitable read across information
- Decision tools for step 5.4 (self-guided tools to help you categorise your introduction)
- hazard characteristics for environment exposure band 1, hazard characteristics for environment exposure band 2, hazard characteristics for environment exposure band 3, hazard characteristics for environment exposure band 4 - use this tool if your introduction is in this exposure band