In the context of LDAR activities, not all emission sources are the same. The experts, in fact, are well aware that the sources relating to substances classified H350 (carcinogenic) enjoy particular attention due to the potential effect of their emissions on human health. The competent authorities, in fact, establish very restrictive limit thresholds for this type of source, typically 500 ppmv against 10,000 / 3,000 ppmv for non-H350 sources. A quarterly monitoring frequency is also prescribed compared to the annual one applied to non-H350 sources.

Finally, speaking of intervention times, in the case of H350 sources that have exceeded the limit threshold, there is an obligation to intervene immediately.

It is therefore necessary to characterize the sources upstream to identify those related to carcinogenic streams.

But what is the method used to define a stream, and consequently all the afferent sources, such as H350?
In the case of streams containing only one chemical substance, well identified, the problem is easy to solve:

“A substance that corresponds to the classification criteria as a category 1 A or 1 B carcinogen set out in Annex I of Regulation (EC) no. 1272/2008 of the European Parliament and of the Council “

In the case of streams containing multiple chemicals we will have that:

“A preparation / mixture,” as required by Legislative Decree 285/98 (replaced by Legislative Decree no. 65 of 14/03/03), is considered carcinogenic when it contains at least one carcinogenic substance in a percentage greater than or equal to 0.1%, except for different and specific carcinogenicity limits indicated in the data sheet of the individual substances in Annex I to Directive 67/548 EEC and subsequent amendments “

It follows that complex realities, where streams are made up of dozens of substances whose composition varies constantly, are faced with a nice headache: how to identify streams that have carcinogenic substances in a concentration greater than 0.1%.

One solution is to identify as H350 all streams related to finished products and / or raw materials, which are themselves H350. This approach is certainly precautionary but leads to an excessive overestimation of the H350 sources with a consequent increase in the management costs of the LDAR program.

The technically more efficient solution, on the other hand, is based on precise monitoring, performed with double instrumentation, capable of detecting on one hand the total emission concentration and on the other the concentration of carcinogenic substances.

In this way it is possible to determine which sources are actually interested in the passage of streams H350.

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