Pentachlorophenol and its salts and esters

Both chemical and non-chemical alternatives exist for PCP within applications for utility poles and cross arms.

Note that following information is extracted from the risk management evaluation document (UNEP-POPS-POPRC.10-10-Add.1).

The preceding chapters have provided a summary description of the key chemical andnon-chemical alternatives. Within North America, chemical alternatives such as CCA and creosote are already in mass production, while new alternatives such as copper naphthenate and ACZA are growing in popularity. The preceding chapter also highlights that the chemical alternatives on the market have their own strengths and weaknesses and may not be directly interchangeable with PCP for specific applications. This is also true for non-chemical alternatives. Furthermore due to their different structural properties, non-chemical alternatives will often not be feasible as replacing individual component poles within established wood pole transmission lines. Table 1 provides a cost comparison provided within the USA EPA assessment of alternatives for PCP (US-EPA, 2008b).

As a separate matter the ICC (ICC, 2014a) states the use of Na-PCP and that alternatives to Na-PCP will take a minimum of 8-10 years to develop, produce and manufacture at competitive price rates to the existing Na-PCP product. Within New Zealand Na-PCP was used primarily as an anti-sap stain rather than preservative and was phased out in the 1980s, with a number of viable alternatives market ready (New Zealand 2014).  The data in Table 1suggest that, based on costs, the use of PCP, CCA, Creosote and Copper Naphthenate are broadly similarly with ACZA approximately $20 per pole more expensive. The costs for ACQ are significantly higher than the other products due to the issue of corrosivity and need for stainless steel fittings. This issue may be countered with the use of micronized ACQ. No costs are provided for copper azoles although they are expected to be more expensive than PCP.

Table 2 displays the costs quoted for non-chemical alternatives per pole and take into account full production and installation costs as well as maintenance. While non-chemical alternatives require lower maintenance than treated wood, the initial installation costs are such that these savings do not off-set additional up-front costs (USEPA, 2008b). When the anticipated longer service life is included, the costs are competitive. This position is based on a case study of a large power distribution utility that found that the 480 installed steel poles out of over 200,000 non-steel utility poles it maintains save the utility 10-20% in lifecycle costs compared with a comparable 480 chemically-treated wood poles(Steel market development institute 2011).

Table 1 Summary of costs quoted in the US-EPA (2008) for chemical alternatives

 * Cost includes $20 for softening agents
** Cost includes the requirement for stainless steel fittings at $37 - $75 per pole.
*** Note that Sodium Borates would not be suitable as a PCP alternative because they are a non-fixed preservative.

Table 2 Summary of costs quoted in the US-EPA (2008) for non-chemical alternatives

* The Alaska Community Action on Toxics note a separate study by SCS Global (2013) which suggests steel poles are of comparative price to treated wood when assessed for full life span and reduced maintenance costs

For further information, please refer to

• UNEP/POPS/POPRC.5/10/Add.1 – General guidance on considerations related to alternatives and substitutes for listed persistent organic pollutants and candidate chemicals
• UNEP/POPS/COP.8/INF/20 – Draft guidance on preparing inventories of pentachlorophenol and its salts and esters and on identifying alternatives for the phase-out of those chemicals
• Risk profile Ar, Ch, En, Fr, Ru, Sp (PDF)
• Risk management evaluation Ar, Ch, En, Fr, Ru, Sp (PDF)