Hazard tanker labels(2)
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by Les Oldridge, T. Eng (CE I), MIMI, AMIRTE IN THE LAST article on this subject, the notices required when single loads are carried were discussed. The notices used when multi-loads are carried in separate compartments on a tanker are identical to the single load ones except the hazard warning sign consists of an exclamation mark instead of a sign indicating one particular substance and in the identification number rectangle the words "Multi load" appear instead of a code number (see figure).
Obviously there is difficulty in displaying a single emergency action code when two or more substances of different types are carried. The procedure to adopt in such cases is set out in Schedule III of the Hazardous Substances (Labelling of Tanker) Regulations 1978, which deal with this subject. These are the rules: (1)The number of the multi load emergency action code is the highest number of any occur ring in the emergency action code for each individual prescribed hazardous substance. Suppose, for example, that hazardous waste sludge containing alkali (emergency action code 2WE) was carried in one compartment and hazardous waste flammable liquid with a flash point of 22C (emergency action code 3WE) in another. The 3 would become the emergency action code number.
(2) To determine the first letter of the multi-load emergency action code take the first letter of the ,emergency code for each indiV4ual substance — (a) 'f it is the same letter in each case then the letter is the first letter of the multi-load emergency action code; (b) if there are two ditterent letters then take one of them and select the vertical column in the code chart reproduced below which is headed (on the top horizontal line) by that letter, then take the other letter and select the horizontal line of letters which has that letter in the left-hand vertical column, then
the letter in the square where the first mentioned vertical column and that horizontal line meet ("the resultant letter") is the first letter of the multi-load action code; (c) if there are three different letters, then take two of them and proceed as in paragraph (b) above, then take the resultant letter and do the same again using the resultant letter and the letter for the third substance, then the letter in the square where the vertical column headed (on the top horizontal line) by the resultant letter and the horizontal line of letters which has the letter for the third substance in its left-hand vertical column meet, is the first letter of the multi-load action code; (d) if there are more than three different letters, proceed as above taking the resultant letter each time with one of the other letters until all the other letters have been used, then the letter in the square when the last other letter is used is the first letter of the multi-load action code.
All this sounds very complicated but in actual fact it is much more simple to carry out than it is to explain. To illustrate what I mean, let us take an actual example. Suppose we want to carry aniline (emergency action code 3X), carbon tetrachloride (emergency action code 2Z) and diquate (emergency action code 2R) in separate compartments on the same vehicle. 3 being the highest number will become the figure in the emergency action code for our multi-load.
We now take the letter X in the top line of the chart and Z in the left-hand vertical column; where these two lines meet we find the letter X and this is our resultant letter. We now take this letter and the letter R which is in the code for our third substance diquate. Finding X in the top column and R in the vertical column, we find where the two columns meet is the letter X, so our resultant letter is the letter X. Our emergency action code for this particular code now becomes 3X.
Looking at the interpretation table discussed in the last article, we find that this means that foam must be used, full protective clothing must be worn and any spillage must be contained, that is, it must not be allowed to enter drains.
In addition to the main notice illustrated in the figure each compartment tank must display a separate notice which must show the identification number of the substance and if that name is displayed the trade name of the substance may be included.
More about these Regulations in the next article.