Phenol, 2-methyl-4,6-dinitro- (4,6-Dinitro-o-cresol) (DNOC)

CAS Registry Number 534-52-1

What is it?

  • Phenol, 2-methyl-4,6-dinitro-, also known as 4,6-dinitro-o-cresol (DNOC), is an industrial chemical.

How is it used?

  • DNOC is used mainly in the plastics industry during manufacturing of styrene and vinyl products.
  • DNOC is used primarily in industrial processes and there is no indication that it is present in consumer products.
  • DNOC is not currently manufactured in Canada, but is imported into Canada.

Why is the Government of Canada assessing it?

  • DNOC was selected as one of the 123 substances for the Screening Assessment Pilot Project.
  • This Pilot Project initially identified 123 substances which were anticipated to be persistent and/or bioaccumulative and inherently toxic to human and non-human organisms and/or to have a high potential for exposure to Canadians.

How is it released to the environment?

  • DNOC may be released to the environment during industrial processes.
  • Upon its release, most of the substance is expected to end up in surface water.
  • DNOC may also form in air when certain chemical reactions take place.
  • DNOC may remain in the environment for a long time when released; however, data suggests that the substance does not significantly accumulate in organisms.

How are Canadians exposed to it?

  • Canadians could be exposed through diffuse releases from industrial sites and the combustion of fossil fuels; however exposure to the general population of Canada is expected to be very low.

What are the results of the assessment?

  • The Government of Canada has conducted a science-based evaluation of DNOC, called a screening assessment.
  • Results of assessment indicate that although DNOC may remain in the environment for a long time, the substance is not expected to accumulate in organisms.
  • Furthermore, the quantity of DNOC that may be released to the environment is below the level expected to cause harm to organisms.
  • The Government of Canada has concluded that DNOC is not harmful to human health at current levels of exposure.
  • The Government of Canada has also concluded that DNOC is not entering the environment in a quantity or under conditions that constitute a danger to the environment or human health.

What is the Government of Canada doing?

  • Based on the conclusion of the final screening assessment, no further action will be taken on DNOC at this time.
  • DNOC is included in Canada's National Pollutant Release Inventory (NPRI). The NPRI is Canada's legislated, publicly-accessible inventory of pollutants released, disposed of and sent for recycling by facilities across the country. Industrial, institutional and commercial facilities which meet legislative NPRI reporting requirements must notify Environment Canada of any releases of substances of concern.
  • The draft of this screening assessment was subject to a 60-day public comment period from June 23, 2007 to August 22, 2007 and the State of the Science Report for a Screening Health Assessment was posted on the Health Canada website on January 30, 2006.
  • The final screening assessment was published on November 28, 2009.

What can Canadians do?

  • The health risks associated with a chemical depend on the hazard (its potential to cause health effects) and the dose (the amount of chemical to which you are exposed).
  • Because exposure to DNOC among the general population is very low, the Government of Canada is not currently recommending specific actions by Canadians to reduce their exposure.
  • As a general precaution, Canadians who handle DNOC in an industrial or manufacturing setting are reminded to carefully follow safety warnings and directions when using products containing DNOC.

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