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Pyrrolizidine Alkaloids (PAs)
in honey

What are PAs? How does it affect our industry? What can we do about it?

The issue of Pyrrolizidine Alkaloids (PAs) in honey is getting a lot of attention internationally. To help our beekeepers we’ve done extensive research to identify the problem and looked at the implications for our industry.

Below, you’ll find some background on PAs, the plant families that produce high levels of PAs and where they are commonly found in New Zealand, and what you can do to mitigate the risk of high levels of PAs getting into the honey you produce. There are also some resources to give you more information and help identify PA producing plants.

Background to PAs

Pyrrolizidine Alkaloids (PAs) are a naturally occurring toxin produced by some plants most likely as a defence against herbivores.

As honey is a food source gathered from nature, PAs make their way into honey through bees collecting nectar and pollen from plants that produce PAs. Of course, this isn’t unique to New Zealand – it’s a global phenomenon, as plants containing PAs are found all over the world.

The issue

The issue for New Zealand producers is that many of the plants containing PAs are widespread in New Zealand and there is a potential concern where PAs at very high levels are consumed over a long period of time. That said, it is important to note that our own Food Standards Safety Authority (FSANZ) and MPI stress there is no evidence to date of harm to humans from PAs in honey itself.

Our research

The industry has been looking at the presence of PAs in New Zealand honey for some time.

Recently, this research has been led by the ApiNZ Standards, Compliance and Regulatory Focus Group in conjunction with the Ministry for Primary Industries (MPI) and Cataylst ® Ltd. It’s been made possible with funding assistance from the Sustainable Farming Fund.

It provides our producers, exporters and hobbyists with more knowledge about PAs and some perspective on their potential risks and impact on our industry, and it allows us to pass on some practical advice to our producers to help reduce PA levels in their honey. Take a look below to learn more, and if you’d like more detailed information, please read the supporting Plant Pack.

PA producing plants of interest

Our research has identified approximately 20 different plant species that are a botanical source of PAs in New Zealand. They come from three families;

Asteraceae, Boraginaceae, Apocynaceae.

For more information and to help you identify plants and weeds high in PAs and where they occur, download our helpful plant information pack.

There are three types of PAs produced by these plants;

  1. Senecionine/Retrorsine type PAs (RET/SEN)
  2. Intermidine/Lycopsamine type PAs (INT/LYC)
  3. Echimidine type PAs (ECH).

You’ll find the common names of these plant types, and the type of PAs they produce in the tables below.

Plants relevant to New Zealand with RET/SEN PA types




Senecio bipinnatisectus
Senecio skirrhodon
Senecio biserratus
Jacobaea vulgaris
Senecio vulgaris
Jacobaea maritima
Erechtites hieracifolius
Brachyglottis repanda
Roldana petasitis
Tussilago farfara

Common name
Australian fireweed
Gravel groundsel
Dusty Miller
American fireweed
Velvet groundsel

Plants relevant to New Zealand with INT/LYC PA types





Borago officinalis
Symphytum sp
Amsinckia calycina
Cynoglossum amabile
Myosotis arvensis
Cerinthe major
Lithospermum sp
Phacelia tanacetifolia
Ageratum houstonianum
Eupatorium cannabinum
Parsonsia capsularis
Parsonsia heterophylla

Common name
Blue borage
Yellow gromwell
Chinese forget-me-not
Field forget-me-not

Phacelia, Purple tansy
Blue billy goat weed
Hemp Agrimony
NZ Jasmine

Plants relevant to New Zealand with ECH PA types




Candiate plants in NZ
Echium vulgare
Echium plantagineum
Echium candicans
Echium pininana

Common name
Vipers bugloss
Pride of Madeira
Giant bugloss

New Zealand geographical PA hotspots

Our research shows that PAs occur in honeys produced throughout New Zealand, particularly LYC/INT PAs, but some regions to date appear to have a higher prevalence in certain PA types.

These areas are:

  • Northland
  • Coromandel Peninsula
  • East Cape through to Wairoa
  • Wairarapa and Manawatu
  • South Island high country and Central Otago

RET and SEN group PAs are more commonly found in the Northland, Coromandel Peninsula and East Cape through to Wairoa regions.

INT and LYC group PAs are more commonly found in the Wairarapa and Manawatu regions.

ECH group PAs are more commonly found in the South Island high country and Central Otago regions.

Risk management for you and your hives

What can you do to reduce the PA levels in your honey?

Take a look below at the PA higher risk habitats, and familiarise yourself with the plants and weeds around your hives and foraging areas.

Remove or avoid high potential PA sources, if possible. If not possible, avoid flowering periods. Use our risk management decision tree to guide your decision-making.

Higher risk habitats

  • Forestry blocks felled in past 5 years
  • Burnt, cleared or barren land that is
 hospitable to Senecio weeds
  • Pasture contaminated with Senecio


  • Bush margins and Parsonsia vines
  • Wild or commercial sites, and
 gardens containing borage, comfrey
 and other Boraginaceae and


  • Wild fields and gardens of Echium


What are PAs?

Pyrrolizidine Alkaloids (PAs). They are naturally occurring toxins produced by a variety of plants all over the world.  PAs can make their way into honey through bees collecting nectar and pollen from plants containing PAs.  They are also present in other food sources.

What is the impact of PAs in honey for consumers?

There is no evidence to date of harm to humans from PAs in honey. Dr Andrew Pearson, Food Risk Assessment Manager at New Zealand Food Safety says: “When we consider lifetime patterns of honey consumption, PAs are not considered a risk for general New Zealand consumers.”

What are the results of the industry/government funded research?

The research carried out by Ministry for Primary Industries, Apiculture NZ (formerly the Bee Products Standards Council) in conjunction with Catalyst ® Ltd. focused on two things: understanding the PA levels in honey and the types of PAs showing up and linking this to the potential botanical sources of PAs in New Zealand, so as to identify those plants.

We’re sharing the findings from this research with our industry so that beekeepers can understand the issue and take proactive steps to reduce risks posed by PAs.

You can also download the plant pack for more information about different types of PAs, the habitats where higher levels of PAs are prevalent, and the plants and weeds that are typically associated with them.

What is industry doing about PAs?

The Industry is taking a proactive, common-sense approach to this issue by reducing the risk posed by PAs wherever possible. To assist the industry, Apiculture NZ is sharing its research findings with beekeepers, honey packers and our marketers.  We’re also providing resources to help mitigate risks around PAs, as well as providing well-researched information to aid decision making.

What can beekeepers do to mitigate the risk of PAs in honey?

Beekeepers should familiarise themselves with the plants and weeds around their hives and bee foraging areas.  If there are high potential PA sources, remove or avoid these plants if possible.  If that’s not possible, then avoid flowering periods. The more awareness beekeepers have about PAs and the plants that contain them, the better informed their decisions can be.

Resources and links to help

For more information and to help you identify plants and weeds high in PAs and where they occur, download our helpful plant information pack.

Check our article in “The New Zealand Beekeeper’ magazine to learn more about our PA research.

Other resources


For images of PA plants uploaded by nature enthusiasts. Enter the plant name in the search field and look for NZ specific uploads.

Plant Conservation Network

For images and general information on PA plants. Enter the plant name in the search field.

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