NERSHCO (Pty) Ltd



1. Certifying a Hazardous Chemical Substance

Certification of a hazardous chemical product places a huge responsibility on the certifying body/company. Very few companies are prepared to even attempt certification, because of its possible ramifications. Nershco has been asked just to do that, although a product has already been certified "safe" by international testing authorities.

The Certification process included the following:

  1. A causal-effect investigation
  2. Occupational hygiene surveys
  3. An audit

The comprehensive occupational health and safety risk assessment model (Schoeman, 1998), which is widely accepted in industry, was applied to the outcome of the occupational hygiene survey.

The outcome was as follows:

The worst case scenario for the hazardous chemical substance was thus classified as a possible risk, which requires some attention.

The converse of the risk model was used and applied to calculate the benefits of using the hazardous chemical substance.

The outcome was as follows:

The risk: benefit ratio thus varies from 1:5 to 1:200.


Contrary to the findings of international testing authorities we concluded that:

Considering the information and research available at the time of the compilation of the report, the hazardous chemical substance could be certified a healthy substance if used in the correct manner and for the purpose it was designed for, provided that employees with a predisposition to respiratory irritation are excluded from a working environment where there is a possibility that they could be exposed thereto, until appropriate investigations as to the effect of the hazardous chemical substance has on people with such medical conditions, have been done.


2. Establishing the Most Probable Source of Environmental Pollution

Subsequent to environmental pollution that took place surrounding a scrubber at a client's premises, Nershco was requested to determine the most likely source of pollution.
Various samples surrounding the scrubber were taken.

These included:

  1. Effluent from the adjacent laboratory flowing towards the scrubber
  2. Effluent from the scrubber
  3. The collective effluent, that from the laboratory and the scrubber
  4. A stack sample
  5. Top soil samples surrounding the scrubber
  6. Sub soil samples surrounding the scrubber

A 16-step process was followed in order to establish a possible link between the effect of a hazardous chemical substance(s) and its most immediate environment. In essence a comparison was drawn between the hazardous chemical substances found during sampling and the Occupational Exposure Limit. The most likely sources of pollution were drawn from the comparison (based on the ratio of the previous exercise) and the known effects of the pollutants were subsequently compared to the effect found in the environment surrounding the scrubber.

The outcome of this investigation suggested that the pollution is possibly the result of hydrogen chloride and/or hydrogen fluoride. Although the analysis suggests that it is due to hydrogen chloride pollution, the visual effects suggest that the primary cause was in fact fluoride pollution.