Step 4.4 Work out your human health hazard characteristics
To work out the human health hazard characteristics your chemical does and does not have, you must know your human health exposure band (Step 4.3). The information you need to consider hazard characteristics varies depending on your introduction’s exposure band.
Then work your way down the hazard bands as far as you need to get to your outcome (that is, C then B then A). After reading this page, go to human health hazard band C hazard characteristics.
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 human health hazard bands
A chemical has a human health hazard characteristic if the chemical can cause damage, harm or adverse effects to humans. For example, a chemical that has the 'skin corrosion' hazard characteristic can cause irreversible damage to the skin of humans.
Human health hazard characteristics are split up into hazard bands. Hazard characteristics of most concern are in hazard band C, while those of lower concern are in hazard band A.
Our pages for human health hazard bands C, B and A describe hazard characteristics (eg carcinogenicity 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 human health exposure band.
If your introduction is in a lower exposure band
Generally, in the lower exposure bands, where the level of exposure to humans 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 humans 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 human health 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
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 human health exposure band (which you worked out in step 4.3) doesn’t require it. For example, if your introduction’s human health exposure band is 1, you only need to consider the hazards in hazard band C to get to an indicative human health risk of either low or very low.
- Because the outcome for indicative human health risk that you are trying to get to doesn’t require it. For example, if your introduction’s human health exposure band is 3 and you want to get to an indicative human health risk of low, you only need to consider the hazard characteristics in human health hazard band C.
In many cases, you’ll only need to consider hazard band C. But in other cases you might need to consider C, B and A, because your introduction is in exposure band 3 or 4 and you are trying to get to very low indicative human health risk.
When you can stop working through your chemical’s human health hazard characteristics
Stop if you:
- determine that your chemical has a hazard characteristic in the hazard band (eg carcinogenicity — you are in hazard band C) 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 human health risk outcome and don’t want to go any further — see step 4.5 for more information about human health risk outcomes or
- have demonstrated that your chemical does not have any hazard characteristics in hazard bands C, B and A. This would only be needed for human health exposure bands 3 and 4. It means that the indicative human health 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, then move to step 4.5.
Example: Anna's introduction is in human health exposure band 4. She considers all of the hazard characteristics in human health hazard band C and can demonstrate that her chemical does not have any of these hazards. Anna then moves on to hazard band B. She works through the hazard characteristics in this hazard band in the order that they are shown in the table. When Anna comes to eye damage, she finds that her chemical has the 'eye damage' hazard characteristic. This means Anna can stop there. The indicative human health risk of Anna's introduction is medium to high. She does not need to continue further to see if her chemical has any of the other hazard characteristics in hazard band B, like skin sensitisation, or specific target organ toxicity after repeated exposure. Also Anna doesn't need to consider if her chemical has any of the hazard characteristics in hazard band A, such as skin irritation.
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 4.4.
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 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 human health 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 and move on to step 4.5.
If your chemical is one of these:
- polyhalogenated organic chemical
- UV filter
- is introduced for an end use in a tattoo ink
- is introduced for an end use in a personal vaporiser
- is introduced for an end use in an article that is a children’s toy or a children’s care product
- is introduced for an end use in an article with food contact
there may be different requirements for you to prove that your chemical does not have certain hazard characteristics.
In most cases we do not expect that you will have information about the high level hazard characteristics in human health hazard band C, such as carcinogenicity. Instead, to demonstrate that your chemical does not have these hazard characteristics you can search the list of chemicals with high hazards for categorisation. This is a list that we have compiled directly from trusted international sources, and provides you with a single place to search for your chemical to check if it might be known to have these hazards. Our hazard band pages tell you when you might need to search the high hazards list.
A list of resources to help you with this step
- List of chemicals with high hazards for categorisation
- In silico information- an overview of which human health and environment (step 5.4) characteristics have in silico options and which in silico models are appropriate.
- Acceptable test guidelines for each human health hazard characteristic listed in this step
- Suitable read across information
- Decision tools for step 4.4 (self-guided tools to help you categorise your introduction):
Human health hazard bands - what are the hazard characteristics in each hazard band
These pages describe the hazard characteristics in each hazard band and the information you need to have to prove your chemical does not have a particular hazard characteristic. Follow instructions on each of these pages. Always start with hazard band C.