133 Molesworth Street
PO Box 5013
Wellington 6140
New Zealand
T+64 4 496 2000
20 November 2024
Robin Benson
By email: [FYI request #29072 email]
Ref:
H2024055415
Tēnā koe Robin
Response to your request for official information
Thank you for your request under the Official Information Act 1982 (the Act) to the Ministry of
Health – Manatū Hauora (the Ministry) on 5 November 2024 for information regarding water
quality in New Zealand. You requested:
The most recent advice the Ministry of Health has given in respect of the current
international approach to PFAS in public water supplies, acceptable levels, etc.
The "international evidence" that advice was based on or confirmed by.
Any discussions, advice or material concerning the consideration of the advice referred to
above "in a New Zealand context".
The Ministry has identified one document within scope of your request, titled: ‘
PFOS and PFOA
– interim guidance level for DW’. This document is appended to this letter and is released to you
in full.
On 29 October 2024, the Ministry commissioned an updated review of the health evidence for a
range of chemicals in drinking water, including Per-fluoroalkyl and Poly-fluoroalkyl Substances
(PFAS). Once completed, this review wil form the basis of policy advice to Taumata Arowai
regarding the drinking water standards.
The Ministry for the Environment - Manatū Mō Te Taiao is the lead agency for the government
regarding PFAS chemicals. Further information is available on their website at:
https:/ environment.govt.nz/what-government-is-doing/areas-of-work/land/per-and-poly-
fluoroalkyl-substances-pfas/latest-updates-on-pfas/
Information about PFAS is also available on Health New Zealand – Te Whatu Ora’s website at:
www.tewhatuora.govt.nz/health-services-and-programmes/environmental-health/hazardous-
substances/persistent-organic-pollutants-pops/per-and-poly-fluoroalkyl-substances-pfas
I trust this information fulfils your request. If you wish to discuss any aspect of your request with
us, including this decision, please feel free to contact the OIA Services Team on:
[email address].
Under section 28(3) of the Act, you have the right to ask the Ombudsman to review any
decisions made under this request. The Ombudsman may be contacted by email at:
[email address] or by calling 0800 802 602.
Please note that this response, with your personal details removed, may be published on the
Manatū Hauora website at:
www.health.govt.nz/about-ministry/information-releases/responses-
official-information-act-requests
Nāku noa, nā
Jane Chambers
Group Manager, Public Health Policy and Regulation
Public Health Agency | Te Pou Hauora Tūmatanui
Page 2 of 2
Poly-fluoroalkyl substances (PFASs), also cal ed perfluoroalkyl substances (PFASs)
Perfluorooctane sulphonic acid (PFOS), and perfluorooctanoic acid (PFOA) belong to a group of
man-made compounds called perfluoroalkyl substances (PFASs). There are thousands of
different compounds classed as PFAS. PFAS accumulate in the human body and without further
exposure the levels decrease slowly over time. The ability of these compounds to be stored in the
body increases concerns about the possible effects on human health. However, there is currently
no consistent evidence that environmental exposures to PFOS and PFOA causes adverse human
health effects.
Adverse health effects have been demonstrated in animals exposed to much higher levels of
PFAS than are known to occur in people. Changes in the liver, thyroid, and pancreatic function,
and some changes in hormone levels were reported. However, the results of these animal studies
and their relevance to humans are not always clear. Potential adverse health effects in humans
ACT 1982
cannot be excluded but further research is needed to understand whether the adverse effects
seen in animals have any implications for human health.
In 2010, the Ministry of Health commissioned Massey University's Centre for Public Health
Research to carry out a biomonitoring study to quantify the concentrations of selected persistent
organic pollutants (POPs) in the blood serum of adult New Zealanders. The study was completed
in 2013 and the results showed that the concentrations of PFOA in adult serum are generally
similar to, or lower than, those in the USA, Canada, Germany, and Australia, while the
concentrations of PFOS are considerably lower than those in USA, Canada, Germany, and
Australia.
INFORMATION
How the maximum acceptable values for determinands in drinking-water are established
The Health Act 1956 provides for the Minister of Health to issue or adopt standards applicable to
drinking-water. Drinking-water Standards may (among other things) provide for maximum
amounts of substances or organisms or contaminants or residues that may be present in drinking
water; and maximum acceptable values (MAVs) for chemical, radiological, microbiological, and
other characteristics of drinking water:
When Health officials recommend a MAV, this is usually adopted from the current guideline value
advised by the World Health Organization (WHO). If drinking water does not exceed the WHO
value it is considered safe for a 70 kg person for a lifetime of 70 years, drinking 2 L per day. The
general procedure for developing a MAV is described in Chapter 10 of the
Guidelines for Drinking-
water Quality Management for New Zealand (MoH 2017), see Appendix 1.
The
Drinking-Water Standards for New Zealand 2005 (Revised 2008) (the Standards) are under
review. Until a MAV appears in the Standards, Health officials propose adopting interim guidance
levels for drinking-water. (The term ‘guideline value’ is already used in the Standards to refer to
aesthetic determinands.)
To develop an interim guidance level we have looked at the equivalent values established in other
countries.
RELEASED UNDER THE OFFICIAL
What guidance values have been established elsewhere?
• World Health Organization: WHO does not have guideline values in the 2017 Guidelines for
Drinking-water Quality.
• Australia:
Per- And Poly-Fluoroalkylated Substances: (NHMRC). 2017. 4 pp.
https:/ consultations.nhmrc.gov.au/files/consultations/drafts/publicconsultationdocument-
draftpfasfactsheet.pdf
• United States:
Fact Sheet: PFOA and PFOS Drinking Water Health Advisories. U.S.
Environmental Protection Agency (USEPA). 2016. 5 pp. From
https:/ www.epa.gov/sites/production/files/2016-
1982
06/documents/drinkingwaterhealthadvisories_pfoa_pfos_updated_5.31.16.pdf
• Germany: Taken from
PFAS Water Supply Testing. Drinking Water Monitoring Report.
ACT
New Zealand Defence Force. Reference: 500307, Revision: 0, 29 September 2017.
Document prepared by: Aurecon New Zealand Ltd.
• Denmark:
Perfluoroalkylated substances: PFOA, PFOS and PFOSA evaluation of health
hazards and proposal of a health based quality criterion for drinking water, soil and ground
water. Danish EPA 2015. Environmental project No. 1665, 2015.
https:/ www2.mst.dk/Udgiv/publications/2015/04/978-87-93283-01-5.pdf
The “guidance values” used in these four countries are:
INFORMATION
Units
Australia
USEPA
Germany
Denmark
μg/L
2017
2016
2015
2015
MEAN
PFOS
0.07
0.07
0.23
0.1
0.12
PFOA
0.56
0.07
0.30
0.3
0.31
Note: We did not consider
enHealth Statement: Interim national guidance on human health
reference values for per- and poly-fluoroalkyl substances for use in site investigations in
Australia. June 2016.
ht p://www.health.nsw.gov.au/env
OFFICIAL ironment/factsheets/Documents/pfas-
interim-health-values-ahppc.pdf This recommended interim health reference values for drinking
water of 0.5 μg/L for PFOS/PFHxS and 5 μg/L for PFOA based on the 2008 European Food
Safety Authority’s (EFSA) derivation of Tolerable Daily Intake (TDI) values for perfluorooctane
THE
sulfonate (PFOS) and perfluorooctanoic acid (PFOA). However, this was not accepted by the
National Health and Medical Research Council (NHMRC), which is the body that prepares the
Australian drinking-water guidelines.
UNDER
Comments:
Australia
• Fact sheet published by the National Health and Medical Research Council (NHMRC)
• Used a similar process to that the Ministry of Health uses for developing MAVs in the
Standards (see Appendix 1 and 2).
• Termed a health-based guideline value.
• Based on Food Standards Australia New Zealand (FSANZ) total daily intakes (TDIs) with an
RELEASED
uncertainty factor (UF) of 30, 70 kg body weight, 2 litres per day, with 10 percent from drinking
water.
• Separate values for PFOS and PFOA.
• The guideline value for PFOS applies to the sum of PFOS + PFHxS (perfluorohexane
sulphonic acid).
Page 2 of 5
United States
• Fact sheet published by the US Environmental Protection Agency.
• Called (non-regulatory) drinking water health advisories, protecting the most sensitive
populations with a margin of protection from a life-time of exposure. These replace the
provisional health advisories of 2009.
• Based on the drinking water intake of lactating women, who drink more water than other
people and can pass these chemicals along to nursing infants through breast milk.
• Same values for PFOS and PFOA.
• Because these two chemicals cause similar types of adverse health effects, USEPA
recommends that when both PFOA and PFOS are found in drinking water the combined
concentrations of PFOA and PFOS be compared with the 0.07 μg/L HA level.
• No value for PFHxS.
1982
Germany
• Not seen original publication – data taken from Aurecon NZ Ltd report. Report possibly called
ACT
Bavarian (Germany) State Office for Environment Provisional Evaluation Criteria for selected
PFAS in groundwater.
• Called provisional threshold value.
• Separate values for PFOS and PFOA.
• Based on human health models for drinking water.
• They developed threshold for six further PFASs, four of which were clearly of lower toxicity.
Denmark
• Fact sheet published by Danish EPA.
• Called health based quality criteria in drinking water.
INFORMATION
• Based on TDIs, with 10% from drinking water, for toddlers drinking 0.03 L per kg per day.
• Despite this different approach, the Danish values are very close to the mean values.
• Separate values for PFOS and PFOA.
• No value for PFHxS, but the PFOS health value applies also to PFOSA
(perfluorooctanesulfonamide).
• Because these substances are toxicologically similar they also have a criterion where the sum
of the concentration/limit value ratios for PFOA, PFOS
OFFICIAL and PFOSA should be kept below the
value of 1.
• WHO and the Standards use this standard approach too, for trihalomethanes and
nitrate/nitrite.
THE
CONCLUSION
For the sake of
interim guidance levels for use in New Zealand, it would seem logical to adopt
the same values being proposed in Australia as their guideline values were very recently
UNDER
developed, and are based on a 70kg adult drinking two litres of water per day, which is consistent
with how MAVs are derived in New Zealand.
If we decide to develop
maximum acceptable values (MAV) for the next Drinking-Water
Standards for New Zealand we wil need to decide on the toxicological pathways most suited to
NZ (and the World Health Organization may have developed guideline values by then).
Units μg/L
RELEASED
PFOS + PFHxS
0.07
PFOA
0.56
Ministry of Health
22 November 2017
Page 3 of 5
Appendix 1
Guidelines for Drinking-water Quality Management for New Zealand.
Excerpt from Chapter 10
For most kinds of toxicity, it is generally believed that there is a dose below which no adverse
effects wil occur. The MAVs for the determinands that are non-carcinogenic or non-genotoxic
carcinogens have been calculated on the basis of a tolerable daily intake (TDI) approach. This is
also called an acceptable daily intake (ADI).
The overall process for deriving the MAVs is presented in the following sections. Information has
been assessed to select the most suitable study to use as the basis for choosing a NOAEL (no
observed adverse effects level) or, if that is not available, a LOAEL (lowest observable adverse
effect level). Sometimes the literature refers to the NOEL (no observed effects level). This value is
1982
divided by an uncertainty factor (UF) reflecting the level of uncertainty associated with the NOAEL
or LOAEL to determine a tolerable daily intake (TDI). The MAV is determined by multiplying this
value by the average weight of a person (BW) and by the proportion (P) of the TDI that a person is
ACT
likely to ingest in drinking-water, and by dividing by the average volume of water that a person wil
drink during one day (C). Definitions appear at the end of section 10.2.5.1.
TDI = NOAEL (LOAEL) and MAV = TDI x BW x P
UF
C
In the individual datasheets the derivation of the MAV of each chemical which has been based
on a TDI approach is shown as a combination of the above two equations as shown below:
INFORMATION
MAV = NOAEL/LOAEL x BW x P
UF x C
where:
TDI/ADI: tolerable/acceptable daily intake (mg/kg body weight/day)
OFFICIAL
NOAEL: no observable adverse effect level
LOAEL:
lowest observable adverse effect level
THE
MAV:
Maximum Acceptable Value in mg/L
BW:
body weight (70 kg for adult; 10 kg for two-year old children; 10 kg calculation
is used for infants for DDT + isomers and 5 kg is used for lead and short-term
nitrite)
UNDER
P:
proportion of tolerable daily intake attributable to drinking-water
C:
the average volume of water consumed per day (adults two litres; children one
litre; infant 0.75 litre)
UF:
uncertainty factor
RELEASED
Page 4 of 5
Appendix 2
Derivation of Guideline (Australia)
PFOS
The health-based guideline value of 70 ng/L (0.07 μg/L) for PFOS was determined as follows:
70 ng/L = 20 ng/kg body weight/day x 70 kg x 0.1
2L/day
where:
• A Tolerable Daily Intake of 20 ng/kg bodyweight per day has been established by FSANZ
1982
on the basis of decreased parental and offspring body weight gains in a multigenerational
reproductive toxicity study in rats.
• 70 kg is taken as the average weight of an adult.
ACT
• 0.1 is a proportionality factor based on the conservative assumption that 10% of the TDI
wil arise from the consumption of drinking water.
• L/day is the estimated maximum amount of water consumed by an adult.
• Because of the large dif erences observed in the half-lives of PFOS in humans compared
to animals, pharmacokinetic modelling was applied to the serum PFOS concentrations
measured in experimental animals at the NOAEL to calculate the human equivalent dose.
The FSANZ TDI incorporates an uncertainty factor of 30, applied to the HED, which
includes a default factor of 3 to account for interspecies dif erences in toxicodynamics and
a default factor of 10 for intraspecies differences in the human population.
PFOA
INFORMATION
The health-based guideline value of 560 ng/L (0.56 μg/L) for PFOA was determined as follows:
560 ng/L = 160 ng/kg body weight/day x 70 kg x 0.1
2L/day
OFFICIAL
where:
• A Tolerable Daily Intake of 160 ng/kg bodyweight/day has been established by FSANZ on
the basis of a NOAEL for fetal tox
THE icity in a developmental and reproductive study in mice.
• 70 kg is taken as the average weight of an adult.
• 0.1 is a proportionality factor based on the conservative assumption that 10% of the TDI
wil arise from the consumption of drinking water.
• L/day is the estimated maximum amount of water consumed by an adult.
• Because of the large di
UNDER ferences observed in the half-lives of PFOA in humans compared
to animals, pharmacokinetic modelling was applied to the serum PFOS concentrations
measured in experimental animals at the NOAEL and above to calculate the human
equivalent dose. The FSANZ TDI incorporates an uncertainty factor of 30, applied to the
HED, which includes a default factor of 3 to account for interspecies dif erences in
toxicodynamics and a default factor of 10 for intraspecies differences in the human
population.
• The rounding conventions described in Chapter 6 have not been applied in the derivation
of the health based guideline value for PFOA.
RELEASED
PFHxS
FSANZ found that there was insufficient toxicological and epidemiological evidence to justify
establishing a TDI for PFHxS. In the absence of a TDI, FSANZ concluded that it is reasonable to
consider that the TDI for PFOS is likely to be conservative and protective of human health as an
interim measure. Ef ectively this means that the guideline value for PFOS should apply to the sum
of PFOS and PFHxS.
Page 5 of 5
