Short answer. In Brazil, potassium iodide (KI) is provided through the public health system (SUS) as 130 mg tablets and 20 mg/mL syrup, under Portaria SCTIE/MS nº 55 of 1 September 2026 1. The order to take it comes from the national nuclear safety authority (ANSN) 1. Adults take 130 mg. Planning zones of 3, 5, 10 and 15 km surround the Angra nuclear plant 12.
Who decides when to take potassium iodide?
The national nuclear safety authority. The protocol states that the recommendation to use KI "will be issued by a technical team of the Autoridade Nacional de Segurança Nuclear (ANSN)" ("Tais definições para a recomendação de o uso do KI serão emitidas por equipe técnica da Autoridade Nacional de Segurança Nuclear (ANSN)") 1. Do not take KI on your own initiative: it protects only the thyroid, only against radioactive iodine, and only when taken at the right time. Our guide on potassium iodide explains how it works.
How is KI distributed in Brazil?
It is dispensed by SUS in a nuclear emergency; states and municipalities keep stock and distribution records 1. The official sources we read do not confirm whether tablets are handed out in advance to households in the Angra zones. If you live near Angra, ask your municipal civil defence (199) or health service how distribution works where you live.
We could not establish from official sources whether KI is sold over the counter or on prescription in Brazilian pharmacies.
Which areas are covered?
The Angra nuclear plant (Central Nuclear Almirante Álvaro Alberto) has four emergency planning zones (ZPE) with radii of 3, 5, 10 and 15 km, centred on the Unit 1 reactor building 12. Eight sirens cover the inhabited area of the 5 km zone 2; see our Brazil alerts page. Our guide on nuclear plant emergency zones explains how such zones are used.
What is the dose?
The Ministry of Health protocol sets doses by age 1:
| Age group | Dose | Tablet or syrup (20 mg/mL) |
|---|---|---|
| Adults and adolescents over 12 | 130 mg | 1 tablet or 6.5 mL syrup |
| Children 3 to under 12 | 65 mg | 3.5 mL syrup or 1/2 tablet |
| Infants 1 month to under 3 years | 32 mg | 2.0 mL syrup or 1/4 tablet |
| Newborns up to 1 month | 16 mg | 1.0 mL syrup or 1/8 tablet |
When should it be taken?
The protocol's window runs from 24 hours before to 2 hours after exposure; taking it up to 8 hours after exposure is still considered reasonable 1. That is why the timing of the ANSN instruction matters: follow it as soon as it is issued.
Frequently asked questions
Can I buy potassium iodide in a Brazilian pharmacy?
We could not establish this from official sources. The protocol covers supply through SUS 1.
Who gets KI in Brazil?
People affected by a nuclear emergency, through SUS, with state and municipal stocks 1. Pre-distribution to households near Angra is not confirmed in the sources we read.
Does KI protect against all radiation?
No. It only reduces the uptake of radioactive iodine by the thyroid. Sheltering indoors and following evacuation orders remain the main protections; see our guide on whether to shelter or evacuate.
What dose for a child?
65 mg for children aged 3 to under 12, which is 3.5 mL of syrup or half a tablet 1.
Sources
- Ministério da Saúde — Portaria SCTIE/MS nº 55, de 1º de setembro de 2026 – Protocolo de Uso do Iodeto de Potássio na Emergência Nuclear — https://www.gov.br/saude/pt-br/assuntos/pcdt/i/protocolo-uso-ki-emergencia-nuclear.pdf (accessed 2026-10-20)
- Gabinete de Segurança Institucional da Presidência da República (GSI) — Existe algum plano para fazer frente a alguma situação de emergência? — https://www.gov.br/gsi/pt-br/assuntos/apoio/acervo/imagens-acesso-a-informacao/plano-para-fazer-frente-a-alguma-situacao-de-emergencia.pdf (accessed 2026-10-20)
Turn this into action
Your plan for Brazil, worked out for your household.
- Water, food and equipment counted for each person and pet
- The nuclear plants and zones around your home
- Phaenyx Safe: one tap to tell your people you are safe
Sources
- Ministério da Saúde · Portaria SCTIE/MS nº 55, de 1º de setembro de 2026 – Protocolo de Uso do Iodeto de Potássio na Emergência Nuclear checked 2026-10-20
- Gabinete de Segurança Institucional da Presidência da República (GSI) · Existe algum plano para fazer frente a alguma situação de emergência? checked 2026-10-20