When we are looking for the hazardous properties of a substance, the product’s Safety Data Sheet (SDS) is usually a good place to start.
Hopefully, if the product is properly labelled, you will been able to tell relatively easily that there is reason to be cautious when using the material.
Information on the label should include hazard symbols, the main health risks, how to use the substance safely and first aid response measures. Watch the Youtube version of this post here…
What is a Safety Data Sheet (SDS)?
If a product is classed as ‘dangerous for supply’, then the producer is obligated to devise a Safety Data Sheet (SDS) that should be made available to distributors and buyers of the product.
A Safety Data Sheet (SDS) provides extensive information on a substance, its supplier and the safe handling and use of it.
The SDS helps us to then conduct chemical risk assessments around the workplace and ensure that each area is safe for work.
SDS Sections
In accordance with the Globally Harmonised System (GHS) for classification and labelling, Safety Data Sheets should contain a pre-defined set of sections with specific information.
The 16 SDS sections are typically laid out as follows:
- 1. Identification
- 2. Hazards Identification
- 3. Composition/Ingredients
- 4. First Aid Measures
- 5. Fire Fighting Measures
- 6. Accidental Release Measures
- 7. Handling and Storage
- 8. Exposure Controls/Personal Protection
- 9. Physical and Chemical Properties
- 10. Stability and Reactivity
- 11. Toxicological Information
- 12. Ecological Information
- 13. Disposal Considerations
- 14. Transport Information
- 15. Regulatory Information
- 16. Other Information
We won’t cover all of the sections in detail here, but we’ll pick out the most pertinent ones to make sure you don’t miss the information you need. Also, we will cross-reference some of the more nerdy, technical stuff where we think it might be helpful.
Let’s take a look at the type of information that we would expect to see in our Safety Data Sheets (SDS), and of course, we’ll focus on the most important parts for helping you manage workplace health and safety….
SDS Section 1 | Identification
Starting with the first section very briefly – this is where you find out the actual product name and the typical uses.
It should also give you names and contact details of the manufacturer/producer of the substance, which is always helpful! See an example above for a sodium hypochlorite (NaOCl) solution – commonly referred to as industrial Bleach – for a Merck product.
Quickly moving on then to the next section, Hazard Identification, which has a bit more meat on the bones for managing the health and safety of users or those who may be affected.
SDS Section 2 | Hazard Identification
In this section, we start to get into the nitty gritty of the hazards presented by the substance concerned.
Depending on the substance, the amount of information here can be a little overwhelming. With that said, let’s break it down into manageable, bitesize pieces.
Classification of Substance or Mixture
Firstly, we have the classification or categories of harm that the substance has been assigned. If you have watched our hazard symbols video, you should be familiar with how substances are classified for different hazard categories.
Let’s continue to use our example of sodium hypochlorite to demonstrate what this means….
The NaOCl has a number of classifications, for harm both to humans and the environment.
Note that the substance is classified for skin corrosion, serious eye damage alongside being both a short and long-term aquatic (environmental) hazard.
Picking one of them, we can see that it has been classified for Skin corrosion (Sub-category 1B).
When a material is corrosive, it will ranked as a 1A (most corrosive), 1B, 1C or 2 (least corrosive).
Being in sub-class 1B, means that this sodium hypochlorite product sits on the higher (more severe) end of the corrosive category scale.
Hazard Symbols
But before we cruise onto those, we musn’t forget our all-important Hazard symbols or pictograms!
You may have noticed in the image above, the red diamond symbols have made an appearance. We have both the Corrosive and the Environmental hazard symbols for the sodium hypochlorite.
Hopefully the presence of these hazard symbols makes sense considering what we have already observed from the safety data sheet.
To give us a bit more of a steer on the potential effects of the product, we can look towards the another major element of this section, the Hazard Statements.
Hazard Statements
The SDS Hazard Statements give us more specific insight into the harmful impacts that may be caused by a substance. For our sodium hypochlorite example, there a couple of hazard statements that sum up the risks;
In this case, we first see the reference to H314. Just below, we can see that this means that the substance ‘Causes severe skin burns and eye damage‘. As we discussed in our Hazard symbols video, for Corrosive materials this harm is likely to be irreversible or result in permanent damage.
Secondly, we see the reference to the aquatic risk, with the H410 code. This signifies that the solution is ‘very toxic to aquatic life with long lasting effects’.
So, that gives us some context as to the risks from this product. It brings our attention towards another element of the hazard identification section that is valuable to us – Precautionary Statements.
Precautionary Statements
It is one thing knowing what the hazards and risks, but we also need to know what to do to avoid harm being caused. The precautionary statements help us to start building a picture of the actions that we may need to take.
The precautionary statements summarise the information that would typically be printed on product labelling.
As you can see, there is even an edited (shorter) version for smaller (<125ml) containers.
It gives us a quick reference overview to what is needed for handling i.e. personal protective equipment (PPE) and response protocols for different types of exposure i.e. inhalation, skin, eyes.
By taking a glance at this section, we quickly find out that this substance requires significant PPE for safe handling. If you are wondering where the detailed guidance on which specific PPE should be worn, don’t panic, that comes later on in Section 8.
OK, slowly breath out. That was quite intense, but now having covered the Hazard Identification section, it will set us up nicely for looking at the other key sections of our safety data sheet.
We won’t go into detail on the ‘Composition/Ingredients‘ section (not essential for you to know this information), but just to say that this section outlines the main constituents of the substance, including concentrations of harmful agents.
In the case of our Bleach (sodium hypochlorite + water) example, this section tells us that our solution is 10-20% sodium hypochlorite. The remainder of the solution is simply water (~80%).
With that bit of extra knowledge on board, it’s time to look at Section 4: First Aid Measures.
SDS Section 4 | First Aid Measures
The next part of the SDS that is important for those managing health and safety is the First Aid Measures section.
The first part (Section 4.1) is usually the main crux of the information. These are the immediate response protocols that are recommended in the event of specifics types of exposure.
OK, that was a mouthful, but what does that mean?
Well, let’s continue with our bleach example here. We are dealing with a liquid in solution in this instance, so the main routes of exposure or entry to the body are going to be contact with the eyes and skin, or via ingestion or swallowing of the substance.
The First Aid measures section should tell us what our appointed first responders should do to help the affected person, for example;
In case of skin contact: Take off immediately all contaminated clothing. Rinse skin with
water/ shower – Emergency shower? Call a physician immediately.
In case of eye contact:
After eye contact: rinse out with plenty of water. Immediately call in ophthalmologist.
Remove contact lenses.
If swallowed
After swallowing: make victim drink water (two glasses at most), avoid vomiting (risk of
perforation). Call a physician immediately. Do not attempt to neutralise.
In the above example, for skin contact, we are advised to rinse the skin thoroughly with water or a shower. This is helpful information when considering what amenities we have available in the vicinity of the work area, such as access to running water.
Depending on the nature of use and the associated risks, you may want to consider the availability of an emergency shower facility, for example.
Another aspect that is quite specific to this product, is that you are advised to allow make the victim drink some water, and instructed specifically to avoid vomiting & attempting to ‘neutralise’.
As sodium hypochlorite solution is strongly alkaline in it’s nature, it may seem somewhat logical to try to get the product out of the system (through vomiting) or to try ‘balancing the pH’ of what has been ingested; evidently, neither of these are medically advisable (according to the manufacturer) and indeed by doing either, you may cause further damage to the health of the person concerned.
As you can hopefully see, it is crucial to understand the guidance on first response treatment for the specific hazardous substance. If we take the wrong course of action we could actually make things worse, and we want to avoid that at all costs.
It is worth noting that there are two other parts in the First Aid section.
Sub-section 4.2 typically provides you with an overview of important symptoms of exposure to help you recognise an issue.
Section 4.3 goes on to provide supplementary medical information that can be useful for medical practitioners, so keep an eye for that information too.
Comparing Similar Products
Our previous sodium hypochlorite example doesn’t elaborate too much upon our hazard statements and cross-references other sections e.g. Sections, 2 (Labelling) and 11 (Toxicological Info.) Let’s take a look at another SDS to give us a better idea of what might expect to see included in this section.
In our comparative example above for a similar bleaching agent with ~10% sodium hypochlorite concentration, we can see a bit more information on typical symptoms and effects.
This includes indicative symptoms such as soreness and reddening of the skin and eyes. Interestingly, this manufacturer has recommended neutralising the product with water.
This brings us to another important point; there are times when I’ve seen directly conflicting advice (such as this) between similar products or even within the same Safety Data Sheet – so bear in mind, the manufacturer’s can make errors in their documentation, so if something doesn’t seem correct, don’t be afraid to contact them for clarification.
SIDE NOTE: If you are unsure or the information isn’t immediately available during an emergency situation, contact emergency services for direct guidance.
SDS Section 5 | Fire Fighting Measures
In this section, we see the recommendations for using extinguishing media in the event of a fire.
As with the others, this section should correlate with the hazardous nature of the products (Refer to Hazard Statements).
In the case of sodium hypochlorite, there was no evidence of it being flammable or explosive in our hazard statements.
Therefore in the Fire Fighting section, our main concern is going to be the potential from contact with the product and the hazardous gases that may be created in the event of a fire.
As you can see below, sub-sections 5.2 and 5.3 refer to hazards that may arise in the event of a fire and the recommendation that fire fighters should wear self-contained breathing apparatus during an emergency response.
For many substances, this section will provide us with specific information on the suitable extinguishing media to be used (and that which is not suitable!).
For example, if we were dealing with a very commonly used cleaning & disinfecting agent such as Ethanol.
We would expect to see the ‘Flammable’ hazard symbol (Section 2) followed by specific advice on fire-fighting and suitable extinguishing methods.
As you can see in the image, it is advised NOT to use a steady stream of water, as it may spread the fire. Also, we can see that there are further hazards to consider, from explosive vapours and combustion by-products e.g. carbon monoxide.
PRO Tip
Make sure to notify your local fire department in respect of what hazardous substances you hold on your site, including quantities and locations – this will allow them to make adequate preparations to respond safely and effectively in the event of a fire emergency.
SDS Section 6 | Accidental Release Measures
Section 6 covers advice measures in the event of accidental release – in other words, spill response!
Most of the information in this section, such as environmental precautions and PPE (which we’ll come to shortly) is usually covered elsewhere.
The part that we normally find most useful here is the ‘Methods and materials for Cleanup’ section.
It’s where we find useful details on how we should safely and responsibly clean up a hazardous substance spill. As we already know with our industrial bleach example, it is harmful to the environment (avoid release to drains/soil/watercourses) and is corrosive (we need PPE to handle).
We can also see a note to ensure adequate ventilation to avoid inhalation of concentrated vapours.
In addition, the cleaning up measures (see above) in 6.3 suggest to use sand or other binding material to absorb the material, before disposing properly. On that note, you will normally find detail on disposal considerations in Section 13, which we are not going to into in detail in this guide.
Section 7 | Handling and Storage
The next Safety Data Sheet section, ‘Handling and Storage’, details the precautions of handling and storage.
Section 7.1 (Precautions for safe handling) is often a reiteration of previously covered info., but it’s always take a look to see if there is anything additional that you need to know. The most value from this part usually comes from storage guidance.
Section 7.2 lets us know how to appropriately store the material, including identifying any incompatible materials.
In the case of NaOCl, it tells us the recommended storage temperature (2-10c), storage conditions and also the storage ‘class’.
For safety reasons, all products to be stored must be classified in the storage class relevant to their specific hazard characteristics.
A chemical can only be classified in one storage class.
For storage, the product is classed as 8B i.e. Non-combustible corrosive. As you can see from the useful graphic (courtesy of Merck) below, a Class 8B product can (in principle) be stored with other substances.
As you may also be able to see from the graphic, this doesn’t mean that it will be able to be stored safely with all other hazardous substances! For example, a Class 1 Explosive Substance or Class 2A Gases should not be stored with Class 8B substances.
Section 8 | Exposure Controls & Personal Protection (PPE)
Now we are on to probably one of the most important sections of our Safety Data Sheet, Section 8, which outlines the necessary Exposure Controls and Personal Protection.
This part can get a little bit technical, but we’ll walk through some examples of what you might expect to see & also outline how you might use the info. in your COSHH Assessment.
We’ll start by using our main example as a starting point, then move from there. The first sub-section (8.1) looks at ‘Control Parameters‘.
Hmm….what the heck does that mean?
Really what this section should provide, is to let us know if there are any exposure limits that we need to know about for any of the harmful ingredients in our product.
If you watched our video on ‘Hazard Symbols‘, you would have seen me talk about Workplace Exposure Limit (WEL’s).
To run over that again, many of the hazardous substances will have Workplace Exposure Limits or WEL’s – this is were a material has been recognised as a significant health hazard and the relevant authorities have determined how much exposure to a substance can be safely tolerated without producing a negative health impact.
Exposure to a substance is uptake into the body. The exposure routes are:
- By breathing fume, dust, gas or mist.
- By skin contact.
- By injection into the skin.
- By swallowing.
The WEL’s work on the basis of exposure via the air in the form of gases (including fumes and vapours), dusts or mists. In the case of NaOCl, we can see (below) that there is no WEL relevant to the material in it’s normal state.
Now, it might be argued that NaOCl contains Chlorine, a highly toxic gas, and therefore should have the relevant WEL listed for that element. We will come back to that point shortly!
As a quick comparison, if we were looking Section 8.1 for another liquid of a similar corrosive nature, Sulfuric Acid, would we find any difference?
Well, it turns out that Sulfuric Acid actually has it’s own WEL.
As you can see, this helpful SDS gives the STEL (Short-term exposure limit) and the TWA (Time-weighted average), which relate to a 15-Minute and 8-Hour period respectively. In this example, it gives us the limits for different jursidictions i.e. UK, Ireland and EU.
You may be asking, why is this helpful or useful?
And that is a great question!
Firstly, it’s good to check if there are any WEL’s associated with your product, it’s a red flag that you are dealing with something that could easily harm your workers.
It is also very useful of course, if you have already identified a need for regular air monitoring. For example, if you have put in place control measures but are still concerned that there is significant exposure to the harmful agent due to variability in the work.
The WEL’s become your key reference point.
Similarly, the figure can be used if you want to carry out a one-off measurement of exposure as evidence that your controls are working and sufficient.
SIDE NOTE: For those responsible for Environmental protection; keep an eye out for the Predicted No Effect Concentration (PNEC) in Section 8.1, which is similar to the WEL but for the aquatic environment.
Personal Protection
OK, let’s move on to the next sub-section, Personal Protection.
It’s here that we can usually find physical specifics on exactly how we should prevent harm from exposure, including use of engineering measures and PPE (Personal Protective Equipment).
Like anything, the quality of the Safety Data Sheet information varies depending on the supplier. Let’s look at some good examples of the type of stuff we expect to see…
Engineering Measures
To start, we can see this example for Sulfuric Acid has given us Engineering Measures to prevent exposure as a first step (before PPE).
As the Hierarchy of Control suggests, Eng. measures are a preferred and more effective method of control than PPE.
Personal Protective Equipment (PPE)
Moving on then to our PPE, this section will help us determine on the specification of protective equipment that we are going to need for our work activity.
As you can see in the image below, we have guidance on eye, hand and skin/body protection.
As with this one, you will often find some detail on the glove material that is suitable for handling. In this case, we are given a couple of different options, with varying materials, levels of thickness and ‘breakthrough times’.
In this case, it is recommending that the product should be handled in an area with adequate ventilation and/or LEV (local exhaust ventilation).
They also advise that processes using the substance should be isolated or enclosed. In other words, you should seek to minimum risk of contact and/or exposure to the sulfuric acid. This SDS also mentions some tips on emergency response, siting the availability of eyewash stations and emergency showers near the work area.
As I’m sure you will agree, this type of information is helpful, and particularly for those who have less experience in dealing with hazardous substances.
The breakthrough times tell us the how long the material will last before failing when continuously exposed to the hazardous substance. As you can see for the 0.5mm butyl rubber, we can only be confident that it will last 120 minutes.
What does this mean for us?
Well, if we carrying out an activity that may result in exposure throughout the course of an entire work day (8 hrs), this option would not be sufficient.
We would want to opt for something more robust, such as a thicker butyl/nitrile glove e.g. 0.11mm, or the Viton (R) option that is provided in the SDS, either of which would have a 480 mins breakthrough time.
Another element of the PPE section that is going to be very useful if you are dealing with respirable substances, is the advice on respirators. Particularly if you are working with exposure levels above that of the WEL’s, or you are just unsure and to be extra cautious if dealing with something nasty.
If you SDS is done well, you might find that the supplier will give you a few different use-cases and recommendations for each.
As you can see above, the advice on respirator specification varies slightly depending on the type of use. The main difference here is that for industrial or emergency applications, a full-face respirator is recommended; whereas for small-scale/lab use, a half-mask with filter is advised.
We’ll not get bogged down in the details of standards and codes and so on here. But hopefully these examples demonstrate clearly that when specifying PPE, the importance of making sure it is at the correct performance level for the hazardous substance and the work application.
Section 10 | Stability and Reactivity
Going back to what we mentioned previously in Section 8.1, although stable under normal conditions, NaOCl has the potential to release chlorine gas. However, this is only under certain circumstances. Section 10 tells us a bit more about these circumstances and what to avoid!
As you can see above, NaOCl can react with acids to release toxic gas (chlorine). Going back to our Handling and Storage section, it turns out that both our example products (Sulfuric Acid and Sodium Hypochlorite) are classed as 8B for storage purposes i.e. non-combustible corrosives.
So, although they can technically be stored together, we would want to ensure that the risk of the two mixing is reduced as far as possible.
Safety Data Sheet | Conclusion
Phew, that was quite a bit to take on board. Now, there are few more sections in an SDS that you may want to pay attention to, including Ecology, Transport & Waste Disposal, depending on what your responsibilities are.
With that said, the ones we have covered here give provide us with the important H&S-related information that we need, snd I really hope that it was helpful for you!
That brings us to the end of our deep dive into the Safety Data Sheets, but make sure to check out our other posts on similar subjects if you got value from this one.
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