We have seen that the MSDS for a particular chemical is the ultimate guide as to its safety.
if a chemical is dangerous it is referring to an acute danger that may result from incorrect transport or storage.
We have also seen that the classification of “poison” doesn’t mean much as it takes no account of the concentration of the chemical in question.
Now we come to the most useful classification in the MSDS – is be chemical “hazardous” or “nonhazardous”. This is a classification that is unique to Australian and European MSDS but you will not find on American MSDS.
The question of whether a chemical is “hazardous” is a subjective classification based on the likelihood (taking into account all of the chemicals properties) of it posing a health risk when used.
That is, the classification “dangerous” is only concerned with transport and storage, and the classification “hazardous” is concerned with its daily use. Let’s gain look at the MSDS of toluene in as an example.
The important section is section 2 – hazards identification. In this section we see the following:
HAZARDOUS SUBSTANCE. DANGEROUS GOODS.
Classified as hazardous according to the criteria of NOHSC, and as Dangerous Goods according to the Australian Dangerous Goods Code.
So we are being told that toluene represents a hazard to our health of some sort. To find out the extent of that we now just read through the rest of the document. A good summary occurs a couple of paragraphs below with:
Harmful: danger of serious damage to health by prolonged exposure through inhalation. Vapours may cause drowsiness and dizziness. Slightly irritating to respiratory system. Irritating to skin. Moderately irritating to eyes. Harmful: may cause lung damage if swallowed. Possibility of organ or organ system damage from prolonged exposure;
Further down below this is more data along with first aid information. So if a chemical is “hazardous” then it represents a risk of some sort to your health.
But, of course, the magnitude of that risk may vary. For example, humble washing soda is also classified as hazardous simply because it can be dusty and act as an irritant, which is obviously a far smaller effect than the toluene.
The beauty of the “hazardous – nonhazardous” classification is that if a chemical is classified as “nonhazardous” then you don’t need to read any further. It has told you that the chemical is perfectly safe.
The other section you need to look at is section 11: toxicological information. This section contains information on how much it takes to kill a rat, which is a direct measure of its toxicity. It also contains any warnings relating to any more exotic effects such as cancer causing, mutation forming, and so on.
So that’s it – you now know how to assess and gauge the significance of classifications of “dangerous”, “poisonous”, and “hazardous”.
And if you can’t find an MSDS for a particular chemical, the chances are that it is completely harmless. Manufacturers have no legal obligation to provide an MSDS for a non-dangerous chemical, so therefore many don’t bother.