FeHEDTA: Concerns Related to Impacts of Permitted Materials on Aquatic Organisms

The following is an extract from a letter I wrote to the Environment and Sustainability Standing Committee (Halifax Regional Municipality Regional Council) on March 2, 2011

- David Patriquin

An area that I think deserves special attention from HRM, and that could benefit from retaining Administrative Order 23 [the list of permitted materials], is the effect of permitted materials, or proposed permitted materials, on aquatic organisms. I suggest it deserves special attention for two reasons:

(i) HRM is an area of high concentration of lakes, rivers and streams which are highly valued for recreational use.

(ii) Some materials that are listed currently as permissible under both the Provincial Act & the HRM By-law are highly toxic to aquatic organisms, notably Pyrethrins and Neem. (Neem is not listed but is used as a plant health promoter by some lawncare enterprises, apparently with the tacit approval of the PMRA.) Please see UPDATE: Use of Pyrethrins and Neem Oil to Control Chinch Bug (http://versicolor.ca/lawns/docs/updateAug07.html) for some comments about these materials.

FeEDTA

The issue of whether to allow FeHEDTA is another case in point. The document Item No. 11.1.5 Halifax Regional Council June 8, 2010 (SUBJECT: Amendment to Administrative Order #23, Respecting Pesticides,

Herbicides and Insecticides - Notice of Motion to Add FeHEDTA (for

lawn use) to the Permitted Pesticides List) includes in full a relevant PMRA Document: Proposed Registration Decision FeHEDTA

PMRA Document Number: 1841244. From the latter:

--FeHEDTA is expected to be non-persistent in the environment (terrestrial and aquatic) under neutral to alkaline aerobic conditions.

--FeHEDTA has a potential for high mobility in sandy soil with negligible organic matter.

--Available information on the effects of iron in ferric sodium EDTA on non-target organisms indicates that the iron in these chelates interacts with the

hemocyanin in the bloodstream of molluscs and crustaceans, and would be toxic to these organisms.

The PMRA document goes on…”However, exposure to freshwater molluscs and crustaceans as well as amphibians is unlikely to occur given the intended use of FeHEDTA as a broadleaf herbicide applied directly to targeted terrestrial plants.”

In regard to HRM, it should be noted that:

(i) soils and water in HRM are generally acidic to very acidic, and many of our lakes with depths greater than 5-6 meters contain anaerobic zones, thus the first statement does not apply well, if at all, to HRM;

(ii) in regard to the second statement above: many, probably most, of our turfs (including lawns) are on shallow sandy soils with low organic matter, so we can expect high mobility in these environments;

(iii) the PMRA acknowledges the toxicity of FeHEDTA to aquatic organisms but suggests that this is not a problem because of “the intended use of FeHEDTA as a broadleaf herbicide applied directly to targeted terrestrial plants.” However, many of our turfs slope directly into lakes, or drain into storm sewers that go into streams and lakes.

So in our area, HRM, these critical assumptions in the PMRA document do NOT apply and extensive use of this material would likely result in significant deleterious impacts on aquatic organisms. As FeHEDTA based products are essentially replacements for traditional broadleaf herbicides, it is likely they would be highly promoted and used if permitted. That would undo a lot of the progress HRM has made since introducing the Pesticide By-law in promoting truly sustainable techniques.

It is pertinent, as noted in the HRM document cited above, that FeHEDTA is NOT approved by OMRI, and that

“According to the Procedures to Amend the Permitted Pesticides List in Administrative Order #23, substances must satisfy the following requirements… 2. The material/substance must not be prohibited by OMRI (Organic Material Review Institute) in their generic names list.”

The HRM staff document goes on to say

“this request meets the primary requirements, with the exception of OMRI approval for the generic product. It is not specifically prohibited nor approved. Iron is approved, with restrictions for use for organic use.”

The last part of this statement is gobbly gunk to justify not applying the OMRI criteria. It is well understood if a material is not on the OMRI list, it is not permitted, further, the forms of iron that are allowed under OMRI are not EDTA forms, and they do have restrictions. This case is in fact a good example of how the OMRI lists are appropriately precautionary and why we should maintain Administrative Order No 23 and its connection to the OMRI lists, rather than

to begin making exceptions to it. (If we do, that will open the door to many more requests, making it unworkable.)

I therefore urge that Administrative Order 23 and its connection to the OMRI lists be maintained and that FeHEDTA not be added to Administrative Order 23.

In the longer term, I hope HRM will look also at some restrictions on Pyrethrins and Neem (e.g., requiring a permit, as under organic certification) because of their impacts on aquatic organisms, and in regard to pyrethrins, their toxicological effects on people. (Pyrethrins/pyrethroids are now the major cause of pesticide incidents in the domestic environment.) We are at the wettest end of the country (except perhaps for coastal B.C., and Newfoundland), and HRM, unlike other areas in the province, has a high concentration of turfs that drain into our streams, lakes, and rivers. Thus there is a good rationale for adding some additional restrictions on cosmetic pesticides to those that are or might be specified at the provincial or national levels.