Australia should mandate a maximum lead content of 0.25 percent in all plumbing products which come into contact with drinking water, a new paper has suggested.

In its latest Consultation Regulation Impact Statement (Consultation RIS), the Australian Building Codes Board (ABCB) has examined the likely costs and benefits associated with three options to reduce the amount of lead which enters drinking water through leeching from plumbing products.

These are:

  • No change (Option 1)
  • Applying a limit of 0.25 percent of lead concentration to all plumbing products used in Australia which come into contact with drinking water (Option 2); or
  • Promoting use of low-lead products through a voluntary industry labelling scheme along with changes to government procurement standards to require low-lead products in government buildings (Option 3).

It said the second option is likely to produce the best outcome.

Based on its central estimates, the ABCB said this option would deliver net benefits of $61.1 million annually or $5.2 billion overall on a present value basis.

By contrast, the labelling scheme would deliver benefits of only $6.9 million annually or $349 million overall (net present value).

“As Option 2 demonstrates the highest net benefit, this option is recommended by this Consultation RIS,” the paper said.

Throughout much of the world and in Australia, lead is used in plumbing products to improve malleability and corrosion resistance.

As far as products which come into contact with drinking water are concerned, it is most commonly found in copper alloys and can be present in fittings valves, taps, mixers, appliances, water heaters and water dispensers. (It can also be found in sprinklers, toilets, boilers and recycled water systems.)

Indeed, a recent ABCB survey found that 90 percent of plumbing products which come into contact with drinking water contain lead to some extent.

Problems can occur, however, where the lead leeches from the products into the drinking water.

When this happens, the toxic material enters the bloodstream and is distributed to organs such as the brain, kidneys, liver and bones.

At high levels of exposure, consequences can include coma, convulsion and death.

Other effects can include reduced intelligence, behavioural changes such as reduced attention span and antisocial behaviour, anaemia, hypertension, renal impairment, immunotoxicity and toxicity to reproductive organs.

These effects – which are most profound in pregnant women and children under four years old – are considered irreversible.

As things stand, use of lead is allowed in small amounts provided that its concentration does not exceed allowable levels.

These vary according to different products and can be as high as six percent for some products.

Allowable lead concentrations within plumbing products are regulated through:

  • manufacturing standards
  • Volume 3 of the National Construction Code (NCC) (commonly known as the Plumbing Code of Australia (PCA)) – which requires that lead water levels in buildings not exceed 10 micrograms per litre as measured under the Australian and New Zealand Standard (AS/NZS) 4020 Testing of Products for Use in Contact with Drinking Water.
  • The Watermark Certification Scheme, which is mandatory for plumbing and drainage products and which requires products to meet specified standards – which in most caters references the requirements of AS/NZS 4020.

Whilst the quality of drinking water in Australia is high, there have been several examples of problems over recent years:

  • In 2016, drinking water at the new Peth Children’s Hospital was found to exceed levels required by the standard AS/NZS 4020 after lead from brass fittings leeched into the water after having undergone a process of dezincification.
  • That same year, a study of 212 homes in New South Wales found that drinking water in 8 percent of homes had lead levels which exceeded allowable limits under the standard.
  • In 2017, the Queensland Building and Construction Commission reported that lead content from a popular type of mixer tap were 15 times permissible levels.
  • In 2018, a random sample of public water drinking fountains in Victorian towns of Queenscliff, Warrnambool and Geelong found samples of lead which exceeded allowable limits.
  • Between October 2017 and May 2020, samples from 272 individual drinking water sources in 21 of the 29 local government areas in Tasmania found approximately 30% had lead content in excess of 10 µg/L.

As shown through laboratory tests, the largest contributor to lead being found in drinking water is by leeching into the water from plumbing products.

As a result, calls to reduce the concentration of lead in plumbing products are growing.

In 2019, 92 percent of participants at an ABCB convened forum involving plumbing manufacturers, chairpersons of Standards Australia’s technical committees, enHealth and plumbing suppliers and retailers agreed that lead content in plumbing products which come into contact with drinking water should be reduced.

As outlined above, two options are being considered (along with a third option of no change).

Under the option recommended in the paper, a maximum allowable lead content of 0.25 percent or less would apply to all plumbing products which are used within Australia and which come into contact with drinking water.

The content would be calculated using a weighted average against the wetted surface area and evaluated against NSF/ANSI 372 – an American standard which establishes a standardised method for determining and verifying the lead content within plumbing products.

This option would involve amendments to the evidence of suitability criteria within the Plumbing Code of Australia to require that compliance with the above requirement be verified through either a test report provided by an accredited laboratory or by any WaterMark certificate which covers compliance with the above standard.

Whilst it acknowledges that costs and benefits associated with this option are difficult to measure, the ABCB estimates that this option would deliver annual net benefits of $61.1 million and overall net benefits on a present value basis of $5.2 billion – with an upper bound estimate of $8.3 billion and a lower bound estimate of $2.6 billion.

Benefits would accrue from health-related factors especially a reduction in ischemic heart disease, stroke and kidney disease.

Costs would occur from price increases for plumbing products which arise from manufacturers needing to source new raw material containing low lead, upgrade equipment and re-tool machines to accommodate low lead plumbing products and undertake testing to demonstrate compliance with the new requirements.

The alternative would involve establishment of a voluntary, industry-led labelling scheme which would assist consumers to distinguish which products contain low-lead levels.

Under this option, changes to government procurement policies would also be recommended at both a Commonwealth and state/territory level to require use of low-lead products in government owed buildings.

The combined objective of both measures would be to promote a market-led shift toward low level lead products.

Courtesy of several factors, the paper indicates that the likely impact and benefit of this option would be limited.

Since the scheme would be voluntary, uptake would depend upon the willingness of both manufacturers to label their products and consumers to seek out and buy low-lead products.

At any rate, split incentives arise as purchasing decisions are not always controlled by end-users.

In rental premises, purchases are made by landlords who may prefer lower cost products as priority over products with low concentrations of lead.

In new builds and major retrofits/renovations, many purchasing decisions for plumbing products are made ‘behind the wall’ by parties other than owners or building occupants.

These decisions may again be driven by cost more so than low lead levels.

Overall, the ABCB estimates that the net benefits of this option would be just $6.9 million annually or $349 million overall in net present value terms.

Accordingly, it recommends the aforementioned limit of lead content within products as the best option.

In its report, the ABCB recommends that proposed limits be incorporated into the 2022 edition of the National Construction Code via Volume 3 (the Plumbing Code of Australia).

To enable manufacturers to adjust processes and to sell existing product, it recommends a three-year transition period.

Feedback on the paper is open until March 1, 2021.