Total Organic Carbon - TOC

UNICERT is the leading inspection body in the area of water quality test for Total Organic Carbon (TOC) and its objectives are to reduce environmental emission/pollution and enhance environmental performance of the society.

Total Organic Carbon (TOC):

Total organic carbon (TOC) is the amount of carbon found in an organic compound and is often used as a non-specific indicator of water quality or cleanliness of pharmaceutical manufacturing equipment. TOC may also refer to the amount of organic carbon in soil, or in a geological formation, particularly the source rock for a petroleum play; 2% is a rough minimum. For marine surface sediments, average TOC content is 0.5% in the deep ocean, and 2% along the eastern margins.

A typical analysis for total carbon (TC) measures both the total carbon present and the so-called “inorganic carbon” (IC), the latter representing the content of dissolved carbon dioxide and carbonic acid salts. Subtracting the inorganic carbon from the total carbon yields TOC. Another common variant of TOC analysis involves removing the IC portion first and then measuring the leftover carbon. This method involves purging an acidified sample with carbon-free air or nitrogen prior to measurement, and so is more accurately called non-purgeable organic carbon (NPOC).


Effects of TOC on environment:

TOC is broken down by aquatic micro-organisms, consuming oxygen in the process. At high TOC concentrations, so much oxygen in the water may be used up that fish and other aquatic animals cannot survive. Low concentrations of TOC encourage the growth of anaerobic bacteria (which do not require oxygen). These can then produce sulfate salts which are toxic to any surviving aquatic life. Anaerobic waters have a distinct smell of bad eggs (due to hydrogen sulfide released from the sulfate salts).

This is usually a sign of extreme organic pollution, although anaerobic conditions do occur naturally in some waters (for example very deep lakes). TOC is unlikely to impact on the global environment. Local effects of man-made TOC have however been observed across the globe, extending into coastal waters of the Baltic, Black and Adriatic seas.


Effects of TOC on human health:

TOC does not directly pose a risk to human health. However in extreme cases where anaerobic (non-oxygenated) conditions result, the toxic salts produced may have adverse effects.


Interested Parties including Regulatory Authorities:

  1. Persons affected by TOC
  2. Industries, Laboratories using/ Generating TOC
  3. Warehouses Containing TOC
  4. Personal and commercial uses of TOC
  5. Private / Govt. Projects to control TOC
  6. Handling and transportation of goods containing TOC
  7. Local Environmental Department/ Authorities
  8. Local Government Authorities like Municipalities, City Corporation etc.
  9. Local Law Enforcing Agencies like Police, Magistrate and Regulatory Authorities etc.

Benefits of Monitoring:

By monitoring long-term contamination trends, every country establishes baseline contamination levels, making it possible for early identification of contamination events. Daily events and long term trends are captured and steps taken to reduce environmental emission/ pollution and enhance environmental performance of the society.