Seed contaminants and tolerance tables

​​​​​All seed consignments imported into Australia for all end uses must meet the standards for seed contaminants and tolerances set by Department of Agriculture, Water and the Environment.

Check the guidance on this page and import conditions in the Biosecurity Import Conditions system (BICON) to understand the requirements you must meet when importing seeds to Australia.

For the purposes of biosecurity, contamination risks of imported seed consignments include: soil, live insects/snails, seed species that have been assessed as a weed risk, unidentified seeds, fungal mycelium (sclerotia, ergot, smut and choke), animal faecal matter and plant material.

How are contaminants identified?

Contamination can be identified by inspection of the consignment and/or based on laboratory analysis of a submitted seed sample from the seed lot. Seed inspection requirements vary based on the seed lot size and size of the seed. As a general rule, the department has adopted the following policy for seeds:

For seed lots less than 10 kg OR seed lots containing seed greater than 8mm diameter

  • The seed lot is subject to inspection by a biosecurity officer on arrival in Australia.
  • The seeds will be inspected visually to assess contamination.
  • If contamination is found, a sample must be drawn in accordance with International Seed Testing Association (ISTA) procedures and submitted to a department approved seed testing laboratory for analysis.

For seed lots greater than 10 kg AND containing seed less than 8mm diameter

  • The seed lot must be sampled in accordance with International Seed Testing Association (ISTA) procedures and methodology, and sample(s) forwarded to a department approved laboratory for analysis.
  • An importer may elect to have this performed offshore or on arrival in Australia.
  • The results of the seed analysis must be presented an official Seed Analysis Certificate, ISTA Orange Certificate or NAL Certificate.
  • The certificate will outline what contamination is present in the sample (purity and other matter).

Note: Further information on ISTA is available at

Can I assess my own certificate?

Note: To convert the number of seeds per kilogram from grams:

Number of seeds (per contaminant) x 1000/bulk sample

Note: A bulk sample is the quantity of seed that was analysed in accordance with ISTA rules

If you choose to have your consignment tested offshore (i.e. prior to arrival in Australia), you may wish to assess the certificate yourself. By assessing the certificate prior to shipping your goods, you may be able to determine whether there are any contamination issues with your consignment and therefore, allow you to remediate the consignment prior to shipping, if necessary.

Please note the department will still need to assess the certificate on-arrival.

Below are the contaminant and tolerance standards seed consignments must meet for:

  • soil
  • contaminant seeds
  • sclerotia
  • animal faecal matter.


Seed must be free of soil. Soil is not always readily visible, but 0.1% has been adopted as the standard maximum tolerance. Seed contaminated with soil above this tolerance must be cleaned, exported or disposed of.


Levels of soil contamination reported on seed analysis certificates are to be rounded to 1 decimal place for assessment purposes. For example:

0.14 per cent would be rounded down to 0.1 per cent and is therefore, below the tolerance level

0.15 per cent would be rounded up to 0.2 per cent and is therefore, above the tolerance level.

Contaminant seeds

Contaminant seeds are grouped into two key categories:

All contaminants detected in a consignment must be assessed if a consignment contains unacceptable contaminants e.g. containing restricted seed species exceeding the tolerance level specified below and/or containing species listed as having a nil tolerance, etc. the consignment is NOT OK.

Restricted seeds

Table 1. Maximum contaminant seeds per kilogram (kg) for restricted seeds
Seed Tolerance (seeds per kg) Seed Tolerance (seeds per kg)
Agropyron spp. 35 Medicago falcata 60
Avena spp. 35 Medicago glutinosa 60
Brachiaria spp. 60 Medicago media 60
Cajanus spp. 60 Medicago sativa 60
Calopogonium spp. 35 Melilotus alba 60
Carthamus tinctorius 35 Melinis spp. 250
Cenchrus spp. (other than C. gracillimus) 35 Onobrychis spp. 250
Centrosema spp. 60 Oryza sativa 5
Chloris spp. 35 Panicum spp. 250
Citrus spp. Nil Pennisetum spp. (other than P. macrourum) 125
Cyamopsis tetragonolobus 35 Phaseolus spp. 25
Desmodium spp. 45 Pueraria spp. 45
Digitaria spp. 125 Secale cereale 35
Eucalyptus spp. Nil Sesamum indicum 60
Glycine spp. 60 Setaria spp. (other than S. faberi) 250
Gossypium spp. Nil Sorghum spp. (other than S. almum and S. halepense) 35
Hibiscus cannabinus 60 Stylosanthes spp. 35
Hordeum spp. 35 Triticum spp. seed from Karnal bunt countries (b) Nil
Lablab purpureus 35 Triticum spp. seed from non-Karnal bunt countries (b) 35
Lactuca spp. (a) 250 Vicia spp. (other than V. faba) 35
Leucaena spp. 25 Vicia faba Nil
Linum usitatissimum 45 Vigna spp. 25
Lotononis spp. 250 x Triticosecale spp. (Triticale) seed from Karnal bunt countries (b) Nil
Manihot esculenta 25 x Triticosecale spp. (Triticale) seed from non-Karnal bunt countries (b) 35
- - Zea spp. Nil

a Excluding Lactuca capensis, Lactuca denticulata, Lactuca pulchella and Lactuca taraxacifolia which have a nil tolerance.
b Karnal Bunt (Tilletia indica) is known to occur in the following countries: United States of America, Mexico, Brazil, India, Iran, Pakistan, Nepal, Afghanistan, South Africa and Iraq.

Seeds with nil tolerance

Seeds with a nil tolerance include:

  • any species listed on BICON as not permitted entry
  • any species listed on BICON as having additional requirements, e.g. requires an import permit, testing, etc.
  • any species not listed on BICON
  • any seed that cannot be identified to species level unless tolerance level for the genus is specified in table 1
  • any seed that cannot be identified to genus level
  • any species listed in Table 2 when being imported into the defined state/s or parts thereof. Note: For all other states and territories these species are permitted entry as contaminants.

Contaminant seeds not listed on BICON or not identified to species level (unless tolerance for the genus is specified in table 1) require an assessment by the department's Plant Import Operations Program prior to any action being taken.

Table 2. Seeds with nil tolerance when being imported into the defined state
Seed Defined State
Convolvulus arvensis Western Australia, South Australia, Victoria
Galium aparine Western Australia
Galium spurium Tasmania
Galium tricornutum Western Australia, Tasmania, certain parts of South Australia

Sclerotia, ergot, smut and choke

Sclerotia, ergot, smut and choke are produced by fungal pathogens and may be present in imported seed consignments and may pose a biosecurity concern.

The following species in the below table are not of biosecurity concern, and may be imported without mandatory seed cleaning:

Table 3: List of non-actionable sclerotia, ergot and smut species on specified seed hosts
Seed host Species not of biosecurity concern
  Any seed species Claviceps purpurea 1, 2
Claviceps paspali 1, 2
Sclerotium bataticola 2
Sclerotinia sclerotiorum 2
Sclerotium rolfsii 2
Tilletia vankyi 2, 3
Lolium spp. or Festuca spp. including hybrids (Festulolium spp.) All ergot or sclerotia2
Agrostis spp., Bromus spp., Cynodon spp., Dactylis spp. or Poa spp. All ergot2

1 Fungi in the genus Claviceps are commonly referred to as ergot

2 May be imported without mandatory seed cleaning if found on the specified host

3 All other reports of smut fungi contamination on seed analysis certificates must be referred to the Canberra office (Plant Import Operations) for advice.

A contamination tolerance level of 0.05% is permitted:

  1. For any species of sclerotia or ergot not listed in table 3; or
  2. Where contamination cannot be identified down to a species level in a consignment.

Alternatively, the department can undertake an assessment of a new contaminant species not listed above. Please note assessments are subject to departmental resources, and may take several weeks.

Animal faecal contamination

Consignments must be free of animal faecal contamination. All reports of faecal contamination on seed analysis certificates must be referred to the Canberra office (Plant Import Operations) for advice.


For consignments of imported pasture seed (such as Lolium spp., Festuca spp., Poa spp., Agrostis spp.) only:

  • A tolerance of 0.01% is permitted for rodent faecal contamination for pasture seed consignments exported from the United States only. The level of rodent faecal contamination (as a percentage) must be stated on an ISTA laboratory report.
  • Consignments are subject to inspection on arrival, to verify freedom from live rodents. There is no tolerance for consignments detected with live rodents.
  • For consignments detected with rodent faecal contamination and no ISTA certification, the seed lot will be subject to an onshore sample being drawn in accordance with ISTA methodology and forwarded to a department approved laboratory for purity testing to determine the percentage of rodent faecal contamination.
Last reviewed: 2 March 2021
Thanks for your feedback.
Thanks! Your feedback has been submitted.

We aren't able to respond to your individual comments or questions.
To contact us directly phone us or submit an online inquiry

Please verify that you are not a robot.