133 Molesworth Street
PO Box 5013
Wellington 6140
New Zealand
T+64 4 496 2000
3 July 2025
Spencer Jones
By email: [FYI request #31211 email]
Ref: H2025068090
Tēnā koe Spencer
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 4 June 2025 for information regarding the fluoridation
of drinking water. Each part of your request has been addressed in turn.
I request the following information regarding fluoride in drinking water under the
Fluoridation of Drinking Water Amendment Act 2021, specifically relating to the Director-
General of Health’s responsibilities under Section 116C. This request addresses
deficiencies in your response (H2025065288, 9 May 2025) and incorporates recent
scientific and legal developments.
1. Detailed Review of NTP Reports (2024–2025):
•
Provide the full review, analysis, or evaluation document conducted by the Ministry or
Director-General of the National Toxicology Program’s August 2024 Monograph and
January 2025 meta-analysis
(https://aus01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fntp.niehs.nih.g
ov%2Fpublications%2Fmonographs%2Fmgraph08&data=05%7C02%7Coiagr%40hea
lth.govt.nz%7Cdfffa33fef5d4ae4f7d008dda31a0ddc%7C23cec7246d204bd19fe9dc44
47edd1fa%7C0%7C0%7C638846054515104839%7CUnknown%7CTWFpbGZsb3d8e
yJFbXB0eU1hcGkiOnRydWUsIlYiOiIwLjAuMDAwMCIsIlAiOiJXaW4zMiIsIkFOIjoiTWF
pbCIsIldUIjoyfQ%3D%3D%7C60000%7C%7C%7C&sdata=AXQdQsBW1SCeM8G%2
B9ju1syaU8GQYuoWarVOvlV%2F3bCE%3D&reserved=0), which found a moderate
confidence link between fluoride exposure above 1.5 mg/L and lower IQ in children,
with effects suggested below this level.
•
Explain the scientific methodology and evidence supporting your conclusion that these
reports do not alter safety assessments, addressing the 95% consistency of 52/55
studies showing IQ reduction.
The Ministry considered the US National Toxicology Program Monograph on the State of the
Science Concerning Fluoride Exposure and Neurodevelopmental and Cognition: A Systematic
Review, published in August 2024. This consideration is available at the link below and includes
the Ministry’s methodology and evidence (please refer to Appendix 5):
www.health.govt.nz/information-releases/director-general-of-health-consideration-of-community-
water-fluoridation-under-the-new-zealand-bill.
•
Clarify whether the consideration cited in H2025065288
(www.health.govt.nz/information-releases/director-general-of-health-consideration-of-
community-water-fluoridation-under-the-new-zealand-bill) includes a specific
assessment of New Zealand’s 0.85 mg/L exposure level and multi-source risks (e.g.,
toothpaste, tea). If not, provide this assessment.
The Ministry has not conducted a specific assessment on a 0.85 mg/L exposure level and multi-
source risks. However, the Ministry has considered evidence on the safety and effectiveness of
community water fluoridation in the following reports.
In 2014, a comprehensive report was published by the Royal Society Te Apārangi, prepared
jointly with the Of ice of the Prime Minister’s Chief Science Advisor, reviewing the substantial
body of scientific evidence on the efficacy and safety of fluoridation of public water supplies.
The report concluded that there are no adverse health effects of any significance from
fluoridation levels used in New Zealand. This is available at:
www.royalsociety.org.nz/assets/documents/Health-effects-of-water-fluoridation-Aug-2014-
corrected-Jan-2015.pdf.
In June 2021, the Of ice of the Prime Minister’s Chief Science Advisor released an evidence
update on community water fluoridation. The update confirmed that there are no significant
negative health effects caused by fluoride at the recommended levels used in New Zealand,
and that the conclusions of the 2014 report remain appropriate. These reviews are publicly
available at:
www.pmcsa.ac.nz/topics/fluoridation-an-update-on-evidence/. In 2024, the Ministry carried out a review of the evidence about the safety and effectiveness of
community water fluoridation published since the Of ice of the Prime Minister’s Chief Science
Advisor report in 2021. The Ministry’s review agrees with the conclusions of the 2014 and 2021
reviews that community water fluoridation is a safe and effective health intervention to prevent
dental caries. This report can be found on the Ministry’s website at:
www.health.govt.nz/publications/community-water-fluoridation-an-evidence-review.
2. Post-August 2024 Scientific Reviews:
•
Provide copies of all reviews, studies, or analyses conducted or commissioned since
August 2024 on fluoride in drinking water, including the October 2024 Cochrane
Review and the Ministry’s 2024 evidence review (www.health.govt.nz, 2024-12-04).
The Ministry consideration of key recent publications, including the October 2024 Cochrane
review of the evidence related to the prevention of dental decay by community water
fluoridation, is available in the same document linked above:
www.health.govt.nz/information-
releases/director-general-of-health-consideration-of-community-water-fluoridation-under-the-
new-zealand-bill.
The Ministry does not consider that these alter the conclusions relating to safety and
effectiveness of community water fluoridation. Please also refer to the 2024 evidence update
linked above:
www.health.govt.nz/publications/community-water-fluoridation-an-evidence-
review.
•
Include any assessments of neurodevelopmental risks, dental fluorosis trends, or
transdermal absorption, given noncompliance with targets (Belotti et al., 2024) and
public health concerns.
•
If no such reviews exist, confirm this and justify the absence despite international
developments (e.g., EPA reassessment, Utah ban).
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You can find specific discussion on the health impacts mentioned in section 6 of the 2021
evidence update provided in the link above:
www.pmcsa.ac.nz/topics/fluoridation-an-update-on-
evidence/.
3. Decision-Making Process Under Section 116C:
•
Detail the criteria, methodologies, and guidelines used to evaluate “relevant evidence”
under Section 116C(4), including how the NTP findings and High Court rulings (2023–
2024) were incorporated.
There is no section 116C(4) in the Health Act 1956. The New Zealand High Court rulings did not
affect the Director-General of Health’s consideration of relevant statutory requirements in
relation to making directions to fluoridate, but instead required further consideration of the Bill of
Rights Act.
•
Provide the cost-benefit analysis for New Zealand’s 0.85 mg/L level, weighing IQ risks
against dental benefits, and address equity impacts in high-deprivation areas.
The Ministry has not conducted this specific cost-benefit analysis for the specific 0.85 mg/L
value; however, the Ministry has carefully considered the evidence on community water
fluoridation and the equity impact. A review of the benefits and costs of Community Water
Fluoridation in New Zealand is publicly available at:
www.health.govt.nz/publications/review-of-
the-benefits-and-costs-of-water-fluoridation-in-new-zealand.
4. Transdermal Absorption and Health Risks:
•
Provide studies or risk assessments on fluoride absorption through the skin from
fluoridated drinking water, given its use in showers and anecdotal reports of adverse
effects.
•
If none exist, explain why this exposure route has not been evaluated, despite its
relevance to compulsory treatment debates.
The Ministry does not hold any information related to this part of your request. Therefore, these
parts of your request are refused under section 18(g)(i) of the Act, as the information requested
is not held by the Ministry and there are no grounds for believing that the information is held by
another agency subject to the Act.
While fluoride can be absorbed through the skin, the amount absorbed from tap water is unlikely
to contribute significantly to overall fluoride exposure. The European Commission states that
exposure pathways from dilute aqueous solutions, like those in showers, are unlikely to
contribute substantially to the body's fluoride burden. The Ministry continues to monitor national
and international evidence. For further information, please see the following link:
ec.europa.eu/health/scientific_commit ees/opinions_layman/fluoridation/en/l-3/2.htm.
5. Correspondence and Monitoring Data:
•
Provide copies of internal/external correspondence (e.g., emails, meeting minutes)
since August 2024 regarding NTP reports, neurotoxicity, or Bil of Rights compliance.
The Ministry has interpreted your request to be for substantive correspondence relating to the
US National Toxicology Program reports, neurotoxicity and Bill of Rights compliance. Al key
documents relating to these matters are publicly available in the links provided to you in this
response. Emails and meeting minutes that are administrative in nature have been excluded.
Therefore, there are no further documents to provide for this part of your request.
Page 3 of 5
•
Supply fluoride concentration data (1992–2025) for all 25 supplies studied by Belotti et
al. (2024), detailing compliance with 0.7–1.0 mg/L targets and exceedances above 1.5
mg/L.
This study was not conducted by the Ministry. This part of your request is therefore refused
under section 18(g)(i) of the Act.
6. Legal and Ethical Compliance:
•
Provide the full Bil of Rights Act 1990 analysis (Section 11) supporting the 2024
directive reconfirmation, including how NTP evidence and public inquiry demands
(e.g., FFNZ) were considered.
•
Explain any plans to align with EPA’s reassessment (2025-04-08) or respond to the
2023 High Court ruling’s process error.
In February 2024, the Director-General of Health was directed by a High Court Judge to assess
whether each of the 2022 directions for 14 local authorities to fluoridate their water supplies was
a demonstrably justified limit on the right of persons in those districts to refuse medical
treatment. The Director-General assessed each direction as directed by the Judge. You can find
information relating to the assessment at:
www.health.govt.nz/information-releases/director-
general-of-health-consideration-of-community-water-fluoridation-under-the-new-zealand-bill. 7. Response to Legislative Reform – Fluoridation (Referendum) Legislation Bil 2025:
•
Provide any internal correspondence, legal advice, or briefing papers held by the
Ministry relating to the introduction of the Fluoridation (Referendum) Legislation Bil by
New Zealand First in 2025.
•
Include assessments of how repeal of the 2021 Amendment Act would affect the
Director-General’s current fluoridation directives and Ministry public health policy.
•
Confirm whether the Ministry has prepared contingency plans or legal risk advice in
relation to this Bil and its potential implementation.
Please ensure responses are specific to drinking water as defined in the Fluoridation
of Drinking Water Amendment Act 2021.
The Ministry does not hold any information in scope of these parts of your request. Therefore,
these parts of your request are refused under section 18(g)(i) of the Act.
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
Ministry website at:
www.health.govt.nz/about-ministry/information-releases/responses-official-
information-act-requests.
Nāku noa, nā
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Clare Possenniskie
Acting Group Manager, Public Health Policy and Regulation
Public Health Agency | Te Pou Haura Tūmatanui
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