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The Ministers of Environment and Health have released for final publication the assessment report for the priority substance Phenol. Notice concerning the assessment of this substance and a summary of its assessment report was published in the Canada Gazette, Part 1 February 5, 2000. The synopsis of the report is provided below.

A draft of this Assessment Report was made available for a 60-day public comment period (May 1, 1999 - June 29, 1999). Following consideration of the comments received, the Assessment Report was revised as appropriate. A summary of the comments and their responses may also be accessed from this page.

For paper copies of the Full Assessment Report, please contact the Inquiry Centre at Environment Canada:

To obtain an electronic version of the Assessment Report in PDF, please request a copy from the following address: ESB.DSE@ec.gc.ca

Synopsis

Phenol is an aromatic alcohol with the chemical formula C₆H₆O. Although phenol is no longer produced in Canada, 76 000 tonnes were imported in 1995 and 95 000 tonnes in 1996. Manufacture of phenolic resins accounts for about 85% of phenol consumption.

Phenol is released to the Canadian environment as a by-product and contaminant from various industry sectors and from municipal wastewater treatment plants. The major industry sectors include the pulp, paper and wood products sector, the mineral (non-metallic) products sector, the chemical products sector, the steel and metal products sector, and the petroleum refining and products sector. In 1996, 321.8 tonnes of phenol/total phenolics were emitted to air and 58.5 tonnes released to water.

The environmental assessment was focussed on releases of phenol to air and water because the largest amounts of phenol are released to these media. Environmental effects are likely to occur close to release areas, because phenol has a short half-life in both air and water. Final effluent (i.e., end-of-pipe) concentrations of phenol from various industry sectors were used to estimate exposure of aquatic biota, because ambient water concentrations were not available. Exposure of terrestrial organisms was investigated for the highest emitters of phenol to air.

For aquatic organisms, the most sensitive assessment endpoint identified was mortality in embryos and larvae of rainbow trout. The meadow vole was selected as the herbivore most likely to be exposed to releases of phenol to air near point sources. Two exposure scenarios were investigated: 1) direct air inhalation, and 2) ingestion and direct air inhalation. The most sensitive organism exposed to phenol in soil is lettuce.

Results of the aquatic assessment demonstrated that for 22 out of 26 pulp and paper mills in Ontario, 6 out of 8 steel mill outfalls in Canada, and 14 out of 16 petroleum refining and production plants in Canada, the probability of phenol causing effects to greater than 5% of aquatic communities is negligible. Of the remaining, the probability of effects greater than 35% for early life stages of the most sensitive aquatic species exposed to phenol near outfalls was low(<5%). Effects near outfalls of municipal wastewater treatment plants due to phenol exposure are not likely.

Results of both exposure scenarios for herbivores demonstrated that phenol released by the highest emitters of phenol to air in Canada is unlikely to cause effects on terrestrial wildlife. Similarly, it is unlikely that phenol causes effects on terrestrial vegetation near high emitters.

Because of the reactivity of phenol in the atmosphere, its Photochemical Ozone Creation Potential is substantial. However, the quantities available for reaction make the contribution insignificant relative to those of other smog-forming substances. Reaction with ozone is negligible, and the absence of chlorine or bromine atoms in the molecule and the overall short half-life of phenol mean that its contributions to stratospheric ozone depletion and climate change are both negligible.

Available data upon which to base estimates of population exposure to phenol in Canada are limited; however, food appears to be the major route of exposure for members of the general population. Intakes are estimated to be elevated for populations in the vicinity of industrial point sources of phenol in Canada. Based on the results of studies conducted in experimental animals, the kidney appears to be a target organ for phenol-induced toxicity. Other sensitive effects observed in laboratory mammals include histopathological changes in the liver and thymus, reduced counts of certain blood cells, suppressed immune response and effects on the nervous system. The estimated average daily intake by the general population from environmental sources and upper-bound estimates of exposures via inhalation for populations in the vicinity of industrial point sources are less than a Tolerable Intake derived on the basis of effect levels for non-neoplastic renal effects. A Tolerable Intake is the level of intake to which it is believed a person may be exposed daily over a lifetime without deleterious effect.

Based on information available, it is concluded that phenol is not entering the environment in a quantity or concentration or under conditions having or that may have an immediate or long-term harmful effect on the environment; constituting or that may constitute a danger to the environment on which human life depends; or constituting or that may constitute a danger in Canada to human life or health. Therefore, phenol is not considered to be "toxic" as defined in Section 11 of the Canadian Environmental Protection Act (CEPA).

The evaluation of options under CEPA to reduce exposure is not considered to be a priority at this time. However, this is based upon current use patterns; future releases of this compound should continue to be monitored to ensure that exposure does not increase to any significant extent.