In 1970, I was in the “cut up” room of the New Zealand Herald catching up on what had been happening whilst I was away on my first tour of South Vietnam.

Naturally, I was drawn to the Vietnam file and after a brief glance placed it back in it position on the bookshelf when I noticed a very slim supplementary file. I can’t remember the title but do remember that it was in there that I first read the word “defoliant” in relation to South Vietnam.

The prompt for the file was the then recently published report by the Bionetics Laboratory’s claim of birth defects and malformations in mice tests using 245T.

If it had run to its full conclusion, that file would have been much larger than the Vietnam file.

Unfortunately, I had left school before Dr DK Sewell of Ivon Watkins Dow in New Plymouth had written on the manufacture of 245T for the science curriculum. Nor was it covered in the Certificate of Science course I sat prior to joining the Army. To find out more about the actions of a defoliant I had to hunt through the science and toxicology texts of the time. 


The object of a defoliant was to drop the leaves off the plant to aid cultivation or harvesting.

In South Vietnam, the object was also to drop the leaves but in much greater numbers and on different species of plants requiring very high concentrations of the chemicals used. This meant applying undiluted Agent Orange, and occasionally using oils as an adjunct to aid dispersal.

Ironically, the first discussion about the military use of Agent Orange occurred during a US Senate hearing on the “Effects of 245T on man and the Environment” in 1970, although there was no debate about the chemical composition of this military stock.

During my second tour to South Vietnam I witnessed the change in the area where defoliation had occurred on my earlier tour and I astounded by the destruction.

By the time I returned to New Zealand, scientists were beginning to investigate aspects of the defoliation program or the individual chemicals that were used. They ranged from the National Academy of Sciences to the USAF, the aerial applicators of the products on behalf of the South Vietnamese Government, and the manufacturers of the products.

Getting rid of the evidence

Around the same time, US military officials began looking at options for disposing their Agent Orange stocks after spraying finished in South Vietnam in 1970.

The simplest solution would be to sell it to domestic users in diluted form. Fortunately, science had passed them by and new dioxin thresholds would not allow it. Amazingly, there was a proposal to plough it into the ground in mile long swathes in South Vietnam and allow natural breakdown of the chemicals. Thankfully, that never happened. A proposal to burn it at sea was opposed by Hawaiian environmental scientists who advocated the recovery of components from the products. The science of dioxin health affects was in its infancy.

Stocks earmarked for destruction were examined using the new testing techniques, and the results combined with a very limited number of historical samples held by the USAF to produce the mean of dioxin in Agent Orange of 2ppm. In reality, it only showed the mean for Agent Orange stocks produced after the industry had put in place measures to reduce the impurity in the finished product, much of which never went to South Vietnam. Sure, there was an evaluation of some ex-Vietnam stocks at Johnson Island but in the main most were of recent manufacture. Perhaps the most interesting was the claim that high dioxin stocks were from the occasional old Agent Purple drums because there was iso octyl ester in the soil at Johnson. No consideration given to the hundreds of drums of Agent Orange II the iso octy version produced because of a shortage of butyl esters.

From this point on a scientific bias against the exposure of troops emerged. There were a number of models used to discount exposure and the majority used the 2ppm mean. This mean would be referenced in all future scientific publications including the National Academy of Sciences.

Some years later, there had been some media reporting of Agent Orange and Vietnam Veterans but this didn’t really tell me anything.

Health questionnaires

In 1980, New Zealand Vietnam veterans received a medical-in-confidence questionnaire from Defence Headquarters with some real obscure questions. I didn’t have any children and couldn’t answer the question “Do any of your children suffer a deforrity?” Deforrity. What the hell is that? Did my godchild, alive of sorts at that time, fit in that category? The parent’s doctor said it was either drugs or chemicals but I never saw him or others of his ilk demand an inquiry.

“Do you think you were exposed to Agent Orange or other defoliants?” It would be three decades before I would be able to answer that with any surety.

The questionnaire was a waste of time and eventually considered inconclusive because the authorities did not know when the spraying program finished. The last I heard, the completed questionnaires remain in a locked cabinet in Defence Headquarters. Unfortunately, the Privacy Act is not retrospective.

They did acquire the information they needed within two years. The Australians had bowed to Vietnam veteran pressure and initiated an enquiry on chemical use in South Vietnam.

Australian & US reports

The Australian government commissioned the Australian Army to research the subject and by the middle of 1982 was ready to present its report. The NZ Army Headquarters received a copy but could not report on it as it was embargoed until it has passed through the Australian Parliament. Remarkably, here was evidence of all the Ranch Hand missions in Phuoc Tuy province, where the majority of New Zealanders served, but it was never utilised until three decades later to establish exposure of NZ troops to defoliants.

Claims by veterans they were sprayed with Agent Orange could have been proven or discounted with that document but it lay gathering dust with the rest of the NZ Defence chemical warfare files.

In May 1983, the Government Cabinet Committee concluded, “there were insufficient Vietnam Veterans in New Zealand to justify and inquiry in this country”. From that point, we would have to wait for the results of Australia’s Royal Commission and the US Ranch Hand studies of crew who flew defoliant aircraft. There was speculation these crew would be the most exposed of all who served in South Vietnam.

Perhaps the most humorous comment was the claim that “The Minister of Health saw a need for caution in handling the situation and this was based on the nature of epidemiological study, a feature of which was the care taken to avoid what was often the temptation to link evidence to possible causes.”

Decades later, conditions on the NAS IOM matrix listing an association but not causality would speed the acceptance of War Disablement Pensions for some veterans.

Later in 1984, another myth around Agent Orange emerged. A thesis on the USAF Ranch Hand missions led to speculation that the code word ‘Ranch Hand’ had been invented to disguise the real name of “Hades” for the defoliation missions. As every soldier knows, mission code names are there to disguise the mission from those who should not know and be immediately recognisable by those who should. Ranch Hand was one of many names with a Texas ranch component that identified 7th USAF missions on behalf of South-East Asian nations. Hades with its three arms of crop destruction, defoliation and perimeter clearance identified the total US chemical mission whilst Orion, the Australian mission was for perimeter clearance only.

In January 1984, the United States District Court of New York notified a legal notice to “all persons who served in or near Vietnam as member of the armed forces of the United States, Australia and New Zealand”. They must have lost mine because I never received anything.

The case resulted in an out of court settlement with American chemical companies in September 1985. This was not an admission of culpability, but an attempt to prevent further legal challenges from veterans. They were not successful, as history would show.

0.2 percent of the total settlement was for New Zealand Vietnam veterans.

I was a work when the announcement was made. A fellow employee came up and said, “All you vets are going to be millionaires.”Another pulled me aside and said, “Do not get your hopes up. The only people who make anything substantive from tort litigation are the lawyers.” How prophetic that turned out to be.

Eventually, the money was put into a Trust to be issued on need and not exposure to chemicals. Much later, another Trust negotiated with the NZ Government who was acknowledging the, “toxic environment Vietnam Veterans served in would have the same conditions in the guise of poverty or hardship”.

In 1986 a special article “The Agent Orange controversy after the Evatt Royal Commission” by Wayne Hall was published in the Medical Journal of Australia claiming the Commission’s report “has authoritatively rejected the claims by” Australian Vietnam veterans on exposure to phenoxy herbicides. Fundamental to that claim was “the Commission called several toxicologist’s to provide opinions on the likely level of exposure. The calculations were….well below the safe no effect levels for 245T and 24D and for TCDD.” That 2ppm mean was in play again.

With the Australian Royal Commission perceived as offering no supporting evidence to Vietnam veterans’ claims, eyes now focused on the US. Whilst the Ranch Hand results were some years away, the National Academy of Sciences Institute of Medicine was tasked to find answers.

At that time, there was no definitive way to ascertain the dioxin levels in individual servicemen and its relevance to Vietnam service.  The Australian Institute of Health considered an adequate exposure index insurmountable. With no exposure methodology available the NAS used as a surrogate meta epidemiological data coupled with biological plausibility to ascertain whether a condition could be associated with dioxin was to be used.

Results were classified into three categories of potential association.

Reeves Report

Whilst the US and Australia accepted the first NAS IOM findings, the New Zealand government was more cautious. It changed its mind after a New Zealand enquiry in 1999 initiated the ‘Reeves Report’.

Most interesting in the terms of reference was the requirement to “Examine the records of the exposure environment…and whether exposure might have occurred.”

The Committee did a “roadshow” and when it arrived at Papakura, I went along to listen.

They weren’t giving much away so I suggested that exposure was going to be problem.  A nod suggested this was accepted, but they provided no detail on how they were going to do it. Eventually asking the question different ways elicited a response that they had all the information they required.

The published report included the statement “Because of the difficulty in establishing which if any (personnel) were exposed”. As a result, they had made a number of assumptions.

I wrote to the Committee with a please explain. Because the Committee had disbanded, this request was forwarded to the Chair. He sent a reply identifying the evidence they had sighted but this made no mention of the Australian Army report, which was gathering more dust. It was revealed later that no one serving on the Reeves Committee had signed it out.

The Reeves Commission formally introduced the NAS IOM matrix as the benchmark for conditions related to service in South Vietnam and New Zealand could now follow the US and Australia.

In 2000, the Chemical companies out of court settlement came back to bite them when two US veterans who had developed cancers after the settlement chose to re-litigate. They lost. Not because they didn’t have a case but because of the now familiar ‘contractor defence’ copout. “They made us make it”. Later Vietnamese claimants would be stymied by the same mechanism although I never understood why the lawyers didn’t seek out claimants who were exposed before the appropriate enforcement legislation was enacted. To me the outcome was predictable yet the media was expressing dismay. Over the years, I have often wondered if the media has any knowledge of the history of this subject at all.

McLeod Report

The next year 2001 saw the results of a meta epidemiological study of literature on chemicals and children of Vietnam Veterans. The conclusions identified the limitations of epidemiology in reaching conclusions with a caveat that “Interpreting this data in a New Zealand context must take into account the very limited potential New Zealand troops had for exposure to Agent Orange. The information available to the authors was that ANZAC Forces generally served in Phuoc Tuy province where there was no aerial spraying.”

Once again the Australian report with its many pages of defoliant mission data was been denied to researchers contracted to the Government of the day. By an organisation that claims all veterans are members of their whanua.

Whilst the study was an informative appraisal of the difficulty of measuring birth defects and cancers in Vietnam veterans’ children, it was the incorrect assertion on exposure that was to earn the wrath of a number of Vietnam veterans in emails to the author of the now called ‘McLeod Report’.

It was the possibility that the angst directed at Dr McLeod might taint the entire Vietnam veteran community that encouraged the officer ilk to finally come on board and start politically organising another investigation.

The subsequent Select Health Committee terms of reference included the point, “Identify and examine evidence that defence personnel were exposed to Agent Orange and other chemical defoliants during the Vietnam War including new evidence recently brought to public attention…”

This was later to called the ‘Master’s Map’. When it was eventually made public, I recognised it straight away. It was a large-scale general-purpose map of known hazards in the ANZAC TAOR showing features such as the signals main transmitter field at Nui Dat. Because of its general nature, the defoliant information was of little value for establishing exposure.  It was a nice political totem though. This became clear when the Minister asked if it was authentic given the tear from the corner. His question and the reply of Officers present that it was “only the South China Sea that was missing” quickly circulated around Vietnam veterans blogs. No one told him it was of no use for identifying individual exposure. That dust gathering Australian report could do that. And it soon did.

Two officers finally dusted the Australian Army report off and using it, the Herbs tapes Mercator coordinates, and commanders’ diaries, were able to give a reasonable facsimile of where NZ soldiers had traversed previously defoliated areas.

The New Zealand Herald of 15 December 2004 said it all. “Vietnam war veterans were “exposed to a toxic environment”. I suspect by this date the old cut up room no longer existed and that slim file was now in some digital archive somewhere.

For me I received confirmation four years earlier when I was forwarded the logs of the USARV Surgeon Generals Office.


The late Allan Stuart alerted me to the facts surrounding the Australian Army report. A simple letter to the Australian Parliamentary Archives allowed me access to a document that been available to any New Zealand researcher since 1982.

Rest in peace Allan. 


Noel Benefield

How to cite this page: 'Observing Agent Orange', URL:, (Ministry for Culture and Heritage), updated 2-Jul-2014