Different herbicides and defoliants were used during the Vietnam War. The one most referred to is Agent Orange. This name derived
from the 55 gallon drum it came in, identified with an Orange band around the drum. There were also:

                     – Agent
Purple: 2,4-D and 2,4,5-T; used between January 1962 and 1964.
                     – Agent
Pink: 2,4,5-T; used between 1962 and 1964.
                     – Agent
Green: 2,4,5-T; used between 1962 and 1964.
                     – Agent
White: Picloram and 2,4-D.
                     – Agent
Blue: contained cacodylic acid (arsenic).

Of course the one mostly referred to is:

                     – Agent
Orange: 2,4-D and 2,4,5-T; used between January 1965 and April 1970.
                     – Agent
Orange II (Super Orange): 2,4-D and 2,4,5-T; used in 1968 and 1969.

These Agents were used by the U.S. Military as part of its herbicidal warfare program, Operation Ranch Hand, they sprayed more than
19 million gallons of herbicides over 4.5 million acres of land in Vietnam from 1961 to 1972.

The heaviest spraying from aircraft in Vietnam occurred during the years 1967, 1968 and 1969. There were often occasions when
troops wearing backpack spraying units were also spraying weeds along roadsides, around camp sites and company areas. Land
Rover mounted units and helicopter units were also used around Nui Dat in various areas.

Agent Orange has been controversial in New Zealand, because of the exposure of New Zealand troops in Vietnam and because of the
production of Agent Orange for Vietnam and other users at the Ivon Watkins-Dow chemical plant in Paritutu, New Plymouth. In
New Zealand there have been continuing claims, as yet unproven, that the suburb of Paritutu has also been polluted. There are cases
of New Zealand soldiers who served in Vietnam with developing cancers such as bone cancer but none has been scientifically
connected to exposure to herbicides. U.S. aircraft were deployed to spray the agents over jungle areas, around roads, rivers,
canals and military bases, as well as on crops that were suspected to be used to supply enemy troops. During this process, crops and
water sources used by the population were also hit. Remember, in all more than 19 million gallons of herbicides over 4.5 million
acres of land.

During 1968 the spraying in the Phouc Tuy province was so frequent that we at most times didn’t recognise craft flying in our area
spraying the jungle. Recognition eventually came only if the craft was directly overhead and you became covered in the spray or if
the craft was so close that you took some cover before you were sprayed.

Through studies done on laboratory animals, dioxin has been shown to be highly toxic even in minute doses; human exposure to the
chemical could be associated with serious health issues such as muscular dysfunction, inflammation, birth defects, nervous system
disorders and even the development of various cancers.

Currently the U.S. Department of Veterans Affairs has listed prostate cancer, respiratory cancers, multiple myeloma, type II diabetes
mellitus, Hodgkin's disease, non-Hodgkin's lymphoma, soft tissue sarcoma, chloracne, porphyria cutanea tarda, peripheral
neuropathy, chronic lymphocytic leukaemia, and spina bifida in children of veterans exposed to Agent Orange as conditions associated
with exposure to the herbicide. This list now includes B cell leukaemia’s, such as hairy cell leukaemia, Parkinson's disease and ischemic
heart disease, these last three having been added on August 31, 2010.

In New Zealand Veterans Affairs list includes prostate cancer, respiratory cancers (lung, bronchus, larynx, trachea), multiple myeloma,
type 2 diabetes, non-Hodgkin’s lymphoma, Hodgkin’s disease, soft-tissue sarcoma, chloracne, porphyria cutanea tarda, acute and
subacute peripheral neuropathy, chronic lymphocytic leukaemia (including hairy-cell leukaemia and other chronic B –Cell leukaemia’s),
Parkinson’s disease and ischaemic heart disease, Hypertension, AL-type primary amyloidosis and stroke.

The lists are identical except the NZ list does not cover spina bifida in children but also includes cover for Hypertension, AL-type primary
amyloidosis and stroke.

In June 2011, a ceremony was held at Da Nang airport to mark the start of US-funded decontamination of dioxin hotspots in Vietnam,
us$32m had been allocated by the US Congress to fund the program.

A us$43m project began in the summer of 2012, as Vietnam and the US force gain closer ties in trade.