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.  On this page you’ll find some background on PAs, the plant families that produce high levels of PAs, and where these are commonly found in New Zealand.  You will also find 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 detailed information, please download our Plant Pack.

Pyrrolizidine Alkaloids (PAs) are a naturally occurring toxin produced by some plants.  PAs are found in 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.

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.”

The research carried out by Ministry for Primary Industries, Apiculture NZ (and 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 identify the potential botanical sources of PAs in New Zealand.

The findings from this research are being shared with our industry so that beekeepers can understand the issue and take proactive steps to reduce any risks.

Industry is taking a proactive, common-sense approach to this issue by reducing the risk posed by PAs wherever possible. To assist industry, Apiculture NZ is sharing the findings of its research with beekeepers, honey packers and marketers and providing resources to help them in decision making.

Beekeepers need to 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.

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.

There are three types of PAs produced by these plants;

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

Please download our Plant Pack for more information and for help identifying plants and weeds containing PAs.


New Zealand geographical hot spots

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

To reduce the risk of PA levels in your honey, take a look below at the higher risk habitats, and familiarise yourself with the plants and weeds around your hives and foraging areas.

Remove or avoid potential PA sources, if possible.  If not possible, avoid flowering periods.

Use our risk management decision tree in the Plant Pack to guide your decision-making.

Higher risk habitats

For RET/SEN PAs:  forestry blocks felled in past five years, burnt, cleared or barren land that is hospitable to Senecio weeds, pasture contaminated with Senecio weeds

For LYC/INT PAs: bush margins and Parsonia vines, wild or commercial sites and gardens containing borage, comfrey and other Boraginaceae and Eupatoriaea.

For ECH PAs: wild fields and gardens of Echium species.

Resources and links to help

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

PA research article
Check out our article in ‘The New Zealand BeeKeeper’ journal to learn more about our PA research.

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.