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Toxic Chemicals in Agriculture

Report to the

Minister of Agriculture and Fisheries

of the Working Party on

Precautionary Measures against Toxic Chemicals

used in Agriculture

LONDON: HIS MAJESTY'S STATIONERY OFFICE

1951

First Published 1951

CONTENTS

Section
I
II
III
IV
V
VI
VII
VIII
IX
X
XI
Appendix :
 
Terms of Reference…………………………………………………
Composition……………………………………………………………
Scope of the Inquiry……………………………………………………
Organizations which have given Evidence………………………………
The Case for their Use ………………………………………
Dangers to Man··· Mode of action ………………………………………
Facts about the Accidents which have Occurred …………………………
Protective Measures stated to be Currently Used …………………………
Protective Measures suggested in Evidence ……………………………………
Conclusions …………………………………………………………………
Recommendations ………………………………………………………
Relative Efficiency of Different Herbicides
Paragraph
1
2
3
4-5
6-14
15-22
23-26
28-29
30
31-52
53-58
Page 16

iii

REPORT TO THE

MINISTER OF AGRICULTURE AND FISHERIES

OF THE WORKING PARTY ON PRECAUTIONARY

MEASURES AGAINST TOXIC CHEMICALS USED

IN AGRICULTURE

1.TERMS OF REFERENCE

1. We were appointed us a Working Party by the Minister of Agriculture
and Fisheries on July 30, 1950, with the following terms of reference;
To make recommendations for the promotion of the safety of workers in
the agricultural use of substances which are toxic or harmful to human beings ;
and in particular to advise on the recommendations on this subject made in
the Report of the Growers Committee on Health, Safety and Welfare in non-
industrial Employment."

II. COMPOSITION

2. The following was the composition of the Working Party :

Professor S. Zuckerman, CB., FRS
(Chairman)
A. H. Bartlett, Esq.
R A. E. Galley, Esq., PhD., A.R.C.S.,
DIC., F.R.I.C.
C T. Gimingham, Esq., O.B.E., B.Sc.,
 
A. Holness, Esq.,
W. Morley Davies, Esq.,M.A., B.Sc.,
F.R.I.C.
J.M. Rogan Esq., M,D., F.R.C.P.E, D.P.H
W. H. Senior, Esq., R.R..S.E.
H. Cole Tinsley. Esq,. M.B.E.
Office of the Lord President of the Council
 
Ministry of Agriculture and Fisheries
Agricultural Research Council.
 
Ministry of Agriculture and Fisheries (Plant
Pathology Laboratory)
Agricultural Improvement Council
Ministry of Agriculture and Fisheries
(National Agricultural Advisory Service)
Medical Research Council
Department of Agriculture for Scotland
Agricultural Improvement Council

JOINT SECRETARIES
K. R. Allen Esq
J.T.Martin,Esq.,Ph.D.,D.Sc.,F.R.I.C.
Office of the Lord President of the Council
Ministry of Agriculture and Fisheries (Plant
Pathology Laboratory)

III. SCOPE OF THE INQUIIRY

3. We have made our inquiry under five main heads, namely :

(a) The nature of the chemicals which have given rise to fears for the health, safety
     and welfare of agricultural workers, and the case for their continued use.
(b) The mode of action of the chemicals ; their dangers to man.
(c) Facts about the accidents which have occurred in the agricultural use of the
     chemicals
(d) The measures which have so far been taken for the protection of the workers.
(e) Protective measures suggested for the future.

1

IV. ORGANIZATIONS WHICH HAVE GIVEN EVIDENCE

4. We have received written evidence from the following organizations;

The Trades Union Congress.
The Scottish Trades Union Congress.
The National Union of Agricultural Workers.
The Transport and General Workers' Union.
The Scottish Farm Servants' Section of the Transport and General Workers Union
The National Farmers` Union.
The National Farmers' Union of Scotland.
The Association of British Insecticides Manufacturers.
The British Agricultural Contractors' Association.

     We have also met the representatives of those organizations and have dis-
cussed with them various points arising from their written evidence.

5. In addition, we have received information in response to a questionnaire
which was circulated through the co-operation of the headquarters of the
organizations concerned, to the Branch Officers of the National Farmers’
Union, the National Union of Agricultural Workers, the Transport and
General Workers` Union and the staff of the National Agricultural Advisory
Service.

V. TOXIC CHEMICALS-THE CASE FOR THEIR USE

6. Many toxic substances are in use in agriculture. The dangers of the
Long-established ones are well known and are guarded against. We have
limited our inquiries to two groups of substances, the aromatic dinitro weed-
killers and the organo-phosphorus insecticides. The first group comprises
such compounds as dinitro-ortho-cresol (DNC) dinitro-sec-butyl-phenol
(DNDP) and their salts; and the second group, parathion,TEPP (including
HETP) and schradan. Recent deaths resulting from the use of DNC, and
illness caused by the organo-phosphorus compounds, have aroused apprehen-
sion.

7. DNC has brought under control some of the most troublesome weeds
which interfere with the production of cereals; in particular, mayweeds
poppies, persicaria, corn marigold, cleavers, and fumitory. All these weeds
are resistant to the growth-regulator types of herbicides. With the exception
of poppies and fumitory, they may be controlled with sulphuric acid but this
has its disadvantages and supplies are very scarce. The degree of control of
mayweeds, camomile, cornflower and corn marigold obtained with sulphuric
acid is substantially less than that achieved with DNC (see Appendix).

8. A further advantage of DNC is that sprayed crops may be undersown
within a short period of treatment. It is used either in the free form or as the
sodium or other salts at the rate of 5 to 9 lbs of active ingredients per 100
gallons of wash per acre, i.e., at a concentration of 0·5 to 0·9 per cent.

9. DNBP has also been widely used as a weedkiller and provides the only
economic control of cleavers, chickweed, veronica, knot-grass and poppies in
peas, where hitherto economic control has not been possible. It is used either
in the free form or as the ammonium salts at the rate of Ύ lb. to 2 lb. of active
ingredients per acre.

2

10. It has been estimated that during 1950, nearly 300.000 acres. were
sprayed with DNC and DNBP compounds*.

11. The organo-phosphorus insecticides parathion, TEPP and HETP are
widely used for the control of aphids on many crops and red spider on fruit,
on hops, and under glass. Their great advantage over the older insecticides,
such as nicotine and derris, lies in the fact that they give a more complete and
dependable control of these serious pests, in particular, of red spider. Their
greater efficiency is reflected in the concentrations used ; whereas for aphids,
nicotine has to be used at a concentration of net less than 0·05 per cent,
parathion and the other phosphorus insecticides used as contact sprays give
an effective control at a concentration of the order of 0·01 per cent. Moreover,
parathion will control aphids at low temperatures at which nicotine would be
almost ineffective. In addition to their use against aphids and red spider, they
have been recommended by the trade for use against thrips,leaf hoppers,
adult white fly, mealy bugs, scale insects and capsids. Their range of usefulness
is extending even further as a result of experiments with other insects ; for
example, parathion has been shown to be effective against leaf miners which
are difficult to control by other means, while recent work has shown its value
against chrysanthemum eelworm which hitherto could be controlled only by
hot-water treatment.

12. Schradan is a systemic insecticide, i.e., it is taken up by the plant and
circulates in the sap in a form that is toxic For weeks to biting and sucking
insects that infest the plant. It represents an entirely new approach to pest
control and has already shown its worth against aphids (particularly of cabbage
and hops) and against red spider. It may prove of value in reducing the trans-
mission of virus diseases.

13. It has been estimated that during 1950, between 50,000 and 70,000
acres were sprayed with parathion, 20,000 with TEPP and 60,000 with schradan*.

14. These substances offer some of the most satisfactory means yet dis-
covered for the control of pests and weeds. They are of great value to the
efficient production of food in this country.

VI. DANGERS TO MAN — MODE OF ACTION

15. We have received information from the Medical Research Council
about the mode of action and dangers to man of DNC and the organo-
phosphorus compounds.

16. Many of the effects of DNC are due to its general stimulant action
on the metabolism of mammalian tissues Death is usually attributed to
hyperpyroxia+, but the real cause probably lies in very subtle disturbances
in cellular metabolism. The acute toxic dose for man is thought to be about
1-2 g. By comparison with nicotine it is much less toxic, since nicotine
has a lethal dose for man of 40 mg.

* These figures have been calculated from the amount of material used. Areas which
were sprayed more than once during the year have, therefore, been counted more than once.
+ An excessively high body temperature

3

17. The lethal dose of DNC is, in fact, so large that human fatalities follow-
ing contact on a single occasion are unknown. The problem is rather one of
chronic toxicity following frequent or prolonged exposure. Under spraying
conditions, when exposure may be relatively continuous, DNC is likely to act
in a cumulative manner. When absorbed, it is destroyed by the body, but when
absorption is continuous it may accumulate faster than it can be destroyed and
thus at fatal concentration may be built up.

18.Several routes of absorption are possible under spraying; conditions
Skin absorption, the inhalation of spray drift, the ingestion of contaminated
saliva and of contaminated food and drinking water probably all contribute
to the accumulation of DNC in the body, although it is not possible to assess
the relative contribution of each route to the final toxic level. The danger of
poisoning through absorption by the skin must be emphasized. Hot weather
can raise the death rate of animals exposed to DNC and is thought to increase
the danger of poisoning in man.

19. Three compounds in the organo-phosphorus group are of immediate
importance, namely, parathion, TEPP and schradan. Parathion is repre-
sentative of the group ; it can be absorbed through the skin and by inhalation
and ingestion. Death can occur as a result of a single exposure ; but chronic
toxicity is the main problem. Repeated absorption of parathion may result in
cumulative poisoning. Parathion appears to inactivate the enzyme cholin-
esterase. This enzyme is intimately concerned in the transmission of impulses
between the nerves and muscles. When the cholinesterase level falls below
50 per cent of normal, symptoms are to be expected. Cholinesterase is present
at the motor nerve endings, and inactivation of the enzyme results in muscular
twitchings and weakness that may develop into paralysis. Death may follow
from paralysis of the respiratory muscles. That part of the nervous system
which controls automatic body processes is also affected. Successive small
doses of parathion may progressively lower the cholinesterase level without
producing symptoms, but may render the individual increasingly susceptible
to further doses. Owing to the slow restoration of cholinesterase to its normal
level, this susceptibility will persist for a long time, maybe for some weeks.

20. The lethal dose of parathion is thought to be about 0·2 - 1·0 g. for a
man of average weight. This is between 1/5 and 1/25 of the toxicity of nicotine.

21. TEPP differs from parathion in having at lethal dose level of about
0·035 mg./kg.* Despite its greater acute toxicity for animals, it appears in
practice to be less dangerous because it decomposes rapidly. In spraying,
contact with the spray drift containing TEPP produces blurring of vision as an
early symptom, so that work has to be given up before more serious symptoms
develop.

22. Schradan has a lethal dose level of about 8 mg./kg.+      It is almost
completely stable in the ordinary conditions of use, and it acts as a systemic
insecticide. When schradan is introduced into animals it is converted into an
active cholinesterase inhibitor.

* 0·035 milligrams per kilogram body weight
+ 8·0 milligrams per kilogram bodyweight

4

II. FACTS ABOUT THE ACCIDENTS WHICH HAVE
OCCURRED

23. It is known that seven agricultural workers have died as a result of
DNC poisoning in Great Britain since 1946 ; in each case dearth followed the
use of DNC as a selective weedkiller in cereal crops. Without exception, the
fatal accidents have been to men regularly employed on spraying and have
occurred during unusually hot weather. The early symptoms of poisoning,
which included fatigue, extensive sweating, thirst, and loss of weight, were
ignored or attributed to the weather and long hours of work. When due to
poisoning by DNC, sweating and thirst may be excessive, and this may be so
marked as to be noticed by other people exposed to the same conditions of
weather. No deaths and no cases of poisoning are recorded following the use
of DNC as a winter wash in orchards, when it is used at a much lower strength
and in weather which is conducive to the wearing of protective clothing. One
man has died and a number of persons have suffered serious illness while
engaged in the manufacture of DNC. Many agricultural workers have
described symptoms suggestive of mild DNC poisoning; occurring during the
cereal crop spraying, season. These men lost more weight and sweated more
profusely than could be adequately accounted for by long hours of work or the
conditions of the weather. One spray operator who had to give up work on
two occasions during the hot summer of 1947 lost two stones in weight in one
week. Profuse sweating and extreme thirst are striking features of DNC
poisoning, and are accompanied by anxiety, restlessness insomnia and
difficulty in breathing. The progress of symptoms from those which might be
attributed to fatigue and hot weather to serious illness and death has been rapid
and dramatic in the fatal cases.

24. In the two fatalities arising from the use of DNC in 1950, it was reported
that the men, both of whom were employees of contractors, had neglected to
wear the protective clothing (rubber boots, rubber gloves, rubber apron, and
eye-shield) with which they had been provided, and that they had worked
excessively long hours in hot weather.

25. Two persons handling parathion in Great Britain in the 1950 spraying
season developed symptoms of parathion poisoning of moderate severity. In
a third case where parathion poisoning was suspected, the exposure to
parathion was remarkably small and cholinesterase activity of the serum and
red blood cells was with within the normal range. In addition to these it
seems likely that mild cases of poisoning from parathion and other organo-
phosphorus insecticides have occurred.

26. In the United States of America, where approximately 300 tons of
technical grade parathion are used each year, 198 cases of poisoning due to
organo-phosphorus insecticides had occurred by September, 1950. Most of
these were due to parathion. Fourteen deaths from parathion poisoning are
known to have occurred in Brazil in the spring of 1950. The low incidence of
poisoning due to parathion in Great Britain is explained by the shorter
experience of its use (approximately ten tons, representing some thirteen
million gallons of spray, were applied during 1950) and greater awareness of
the risks involved.

5

VIII. PROTECTIVE MEASURES STATED TO BE
CURRENTLY IN USE

27. The following is a list of precautionary measures which have been
reported to us as used or suggested for use. Most of these are recommended
by the manufacturers ; a number of them are recommended by the
Contractors` Association to their members. Few people look to all of these
precautions ; some look to none :
    (i) The provision of gas-proof, air-conditioned cabs on the tractors.
    (ii) Rest periods of a minimum of two clear days away from spraying in every fourteen
days. Short working hours when the sun temperature is over 75 o F.
    (iii) Where possible, the concentrated chemicals are handled in bulk, avoiding the opening
of numerous tins which is liable to result in splashing of the operators. Where bulk handling
is not practicable safe disposal of used containers is ensured. Use of "anti-splash"
containers with screw-on pouring spouts and large outlets (in no case should the material be
supplied in open-topped drums). Use of easily handled packs.
    (iv) Plenty of clean water and soap for washing available at the site of mixing. Separate
water container for washing (a) gloves, before they are removed, (b)the hands and face
    (v) Protective clothing, including white overall with hood, natural rubber gloves, rubber
boots with steel caps, mackintoshes. "Neoprene" clothing and masks.
    (vi) The issue of prophylactic medicine and a special supplementary diet said to increase
resistance.
    (vii) Regular weekly medical examination of all workmen to ensure that dangerous
quantities of toxic substances do not accumulate in their bodies.
    (viii) The provision of first-aid kits containing antidotes for use in emergencies; also
instructions for treatment of casualties which can be handed to a doctor.
    (ix) Training the operators to be "safety conscious".
    (x) Qualified supervision of all workers engaged on the use of dangerous sprays.
    (xi) Suspension of spraying operations in windy weather.
    (xii) Workmen instructed that they must not clear blocked jets by blowing out with the
mouth.
    (xiii) Surplus material disposed of without contamination of ponds or streams.
    (xiv) Spraying machines, hoses and lances washed with water before repairs are made, and
at the end of each shift; tanks and containers washed thoroughly at the end of each shift.
    (xv) Workmen instructed that they should remove overalls promptly at the end of the
spraying operations and change into ordinary clothes before leaving the farm.

28. In further evidence, the Contractors` Association said that not more
than 5 per cent of the tractors used for DNC spraying were fitted with gas-
proof, air-conditioned cabs. Moreover, the operator who attends to the
spraying nozzles sometimes rides outside the cab and cannot therefore shelter
within its protection.

29. The organo-phosphorus insecticides, and DNC when used as an
insecticide (but not as a weedkiller), are scheduled under the Pharmacy and
Poisons Act, 1933, as Part II Seventh Schedule Poisons by an Order which
came into operation on April 11, 1949. This imposes a requirement that a
cautionary statement about the dangers of these chemicals and the percentage
of active ingredients in the prescribed form should appear on the labels of
containers. The manufacturers voluntarily include the word " Poison " on
the labels of containers together with a great deal of information about the
precautions which should be taken in handling the material. The Association
of British Insecticide Manufacturers has laid down a strict code for observance
in factories and has drawn up a statement of dangers and precautions for
the information of purchasers of the materials.

6

IX. PROTECTIVE MEASURES SUGGESTED IN EVIDENCE

30. The following additional suggestions have been made to us in the
evidence received from the organizations named in paragraph 4, for the further
protection of workers engaged in the agricultural and horticultural use of
dinitro and organo-phosphorus compounds :
    (i) A list of protective clothing. including rubber boots, rubber gloves. rubber apron,
respirator or eye-shield, and overalls, to be available for reference by both employer and
employee. The protective clothing should be changed frequently.
     (ii) In addition to soap, water and towels provided in the field facilities should be provided
for bathing and changing of clothes at the end of the day’s work. Gloves and boots should
be washed, preferably with running water, before removal.
     (iii) Medical supervision should include routine medical examinations at weekly intervals,
with suspension of workers who show any trace of early toxic symptoms. Also expert super-
vision of first-aid and prophylactic measures.
     (iv) A limit should be placed on the period during which any one worker may be engaged
on spraying operations.
     (v) The smallest possible number of workers should be exposed to risk arising from the
mixing or other handling of the chemicals. Only the most responsible employees should be
given these duties.
     (vi) All workers and other persons handling the materials or otherwise exposed to risk
should receive detailed instruction on dangers and precautions from a qualified instructor.
Instruction should include demonstrations and lectures,
    (vii) Research should be undertaken into the safest types of protective equipment, con-
tainers, spraying equipment, etc.
     (viii) A notification should be sent to the local doctor before spraying operations are
undertaken in his area in order that he may look for symptoms of DNC and parathion poisoning
in patients who may report to him after using the sprays.
    (ix) Information on the pharmacology of toxic chemicals and the treatment of casualties
should be made specially available to general practitioners.
     (x) Research should be undertaken in order to find antidotes for DNC and parathion
poisoning.
     (xi) Chemical manufacturers should not market any new insecticide or other preparation
until they have thoroughly studied the acute and chronic toxicity of the compound, and issued
extensive information about its toxic nature and prevention of accidents.
     (xii) manufacturers should be required to state on the labels of containers;

(a) the name of the active ingredient ;
(b) the percentage of active ingredient ;
(c) its toxic nature and mode of action ;
(d) precautions and antidotes, and the safe intervals which must be observed between
    spraying and harvesting, also whether danger to other workpeople exists after
    the crop has been sprayed.
    (xiii) Research should be instituted in order to find insecticides and weedkillers which are
fully effective in their agricultural use but are harmless to man.

X. CONCLUSIONS

31. We are of opinion that until harmless alternatives can be found, the
use of dinitro weedkillers and organo-phosphorus insecticides must go forward.
The importance of the greatest possible agricultural production to our national
economy, in peace or war, needs no emphasis. The chemical compounds
with which our inquiry has been concerned are fulfilling an important role in
the control of weeds and pests and are thus contributing no small measure
to efficient agricultural production.

32. Our task, therefore, is to recommend measures for the protection of
the workers who are handling these chemical compounds in agriculture, on
the assumption that they will be used on an increasing scale.

7

33. Measures appropriate in the case of DNC and parathion would also
be applicable to other compounds in these groups.

34. We have considered the suggestions which have been put forward in
evidence, and we are glad to be able to report that the representatives of the
organizations from which we received evidence agreed on the essential protective
measures.

Insulation of the Worker - Protective Clothing

35. The most important element of protection is, of course, the clothing
issued to the worker. Clearly, complete protection would be enjoyed by a
man completely clad in impervious clothing such as rubber coat, boots, gloves
and wearing a respirator, but we are satisfied that a man so encumbered would
collapse within a very short time from the excessive heat engendered through
lack of ventilation. Furthermore, it must be recognized that spraying operations
take place up to mid-June, that warm weather may be expected during part
of that period, and that the hazards are greater in warm weather.

36. Ideal protective clothing would be impervious to the chemicals but
would allow proper ventilation to the body of the wearer. We know of no
material which combines these qualities and we are in consequence unable to
recommend clothing which is both practical and completely effective. Natural
rubber and oiled materials, e.g., oilskin, are probably the most efficient
protective materials for this purpose. Some types of plastic may also be
satisfactory, but we understand that other plastic materials offer little protection
against organo-phosphorus compounds in concentrated form. We think,
therefore, that if protective clothing of other material than natural rubber is
purchased, un assurance should be obtained from the manufacturers that it
will give adequate protection against organo-phosphorus insecticides. Through-
out this report we speak of " rubber ", but this should be taken to include
other materials which are shown by their manufacturers to give a degree of
protection equal to that of natural rubber.

37. We think that adequate protection to the worker in the field can be
given by rubber gloves, rubber boots, an eye-shield and white cotton overalls
with a hood, on the understanding that both workers and supervisors would
be on the look-out for discoloration of the garments from splashes or contact
with spray drift, and that the clothing would be changed when discoloration
appeared. The worker engaged on mixing the concentrate in a building or
other enclosed space, and the men employed on spraying in greenhouses or
required lo enter a fumigated greenhouse before it had been thoroughly venti-
lated, would need the additional protection of a respirator. The ideal respirator
for these purposes has yet to be produced, but adequate protection can be .
afforded by the Home Office civilian duty mask and by certain commercially
available types of respirator such as the " Puretha CC." These are, however,
unnecessarily heavy and we think that research should be undertaken to find
a completely satisfactory respirator. Until further quantitative data are avail-
able, the service life of the civilian duty mask in concentrations of parathion
of 1 g. per 1,000 cubic feet or less, is estimated at not more than 250 hours
The service life of the "Puretha C.C." type of respirator in similar conditions
is estimated at no more than 1,000 hours.

8

38. The gas-proof air-conditioned cab is an excellent protection for the
tractor driver, provided it is frequently tested and that he does not contaminate
it from previous contact with the spray. But special protection is necessary
for a worker who rides on the sprayer in order to control the spray nozzles,
and is outside the protection of the cab. We consider that the circumstances
in which this man is working would not result in intolerable discomfort from
the wearing of a rubber overall, gloves and boots and a respirator or eye-shield,
and we think that he should be so protected.

Instruction in Dangers and Precautions

39, it is clear from the evidence received that, despite the present anxiety
in the agricultural community about the dangers of the new chemical com-
pounds many of the men engaged in using them have shown an astonishing
degree of carelessness about their own safety. We conclude that this must
be due to a lack of awareness of both the acute and the chronic effects of the
substances, and we consider that it is imperative for all concerned - workers,
farmers, contractors, indeed all whose work brings them into contact with the
substances - to be thoroughly educated in their dangers and in the precautions
which should be taken. This is a matter in which the Agricultural Departments
and the organizations representing farmers, workers, manufacturers, and
contractors can all play a part.

40. We are of opinion that the co-operation of the British Medical Asso-
ciation should be enlisted in order to bring the dangers, mode of action and
appropriate treatment for DNC and parathion poisoning to the notice of
medical practitioners. We endorse the suggestion that medical practitioners
should be warned when spraying is to be undertaken on farms in their locality,
and we think that the warning should include local hospitals in order that they
may be ready to deal with any patients who may be suffering from DNC or
parathion poisoning.

Prophylactic Measures and Supplementary Diet

41. We can find no evidence to support the view that the risks can be
reduced by means of a prophylactic medicine or that a supplementary diet
effectively increases resistance to the dangers.

Regular Medical Examination

42. We are not convinced that the British Agricultural Contractors'
Association‘s regular medical examination of their operatives provides a reliable
means of safeguarding the health of workers in the field. Furthermore, it
must be recognized that many farm workers other than contractors` employees
are engaged from time to time on spraying operations and organized medical
examination of these men would obviously be difficult to arrange. Any worker
showing the first signs of even the mildest form of poisoning should, however
go to a doctor for examination.

Maximum Working Periods,

43. We are strongly of opinion that whatever the urgency of the task on
which the men are engaged they should not be allowed to risk prolonged

9

exposure to the dangers of the dinitro and organo-phosphorus compounds
We find some difficulty in recommending safety measures in this respect, but
we consider that 10 working hours a day and 6 days a week should be regarded
as the maximum for any worker. We consider that men should not be per-
mitted to go on with this type of work if they are suffering from any minor
disorder such as a cold, bronchitis or stomach upset.

Supervision

44. We are convinced that proper and efficient supervision is of the utmost
importance. The supervisor should have a thorough knowledge of the dangers,
symptoms, first-aid measures and precautions, and should be selected with
care to ensure that he is a good leader in the fullest sense of the word.

45. We agree that, as far as possible, the materials should be bulk handled,
and that they should be mixed before spraying by a worker selected for his sense
of responsibility. The greatest care in handling the materials is essential.

Washing Facilities

46. It is clearly necessary that soap, clean towels and an adequate supply
of clean water should be made readily available to the spraying teams in the
field. Special precautions are necessary to ensure that the water does not
become contaminated by spray-drift. The workers should wash thoroughly
before leaving the field for meals and before leaving work at the end of the day.
Running water should be used. When this is not available, separate, clearly
marked water containers should be provided for washing, first the rubber,
boots and gloves, and, secondly, the hands and face. We do not think that the
provision of bathing facilities would contribute adequately to the safety of the
workers unless a shower could be provided. There are obvious dangers in
the use of a single bathroom by a succession of men because of the build-up
of toxic contamination.

Meals

47. On no account should the workers be permitted to take their food and
drinks into the field in which they are spraying and smoking should be forbidden
during spraying because of danger of contamination of pipe or cigarette.

Manufacturers' Responsibilities

48. We have examined the labels of containers presented for our inspection
by the Association of British Insecticide Manufacturers, and we are impressed
by the amount of cautionary and instructive matter which the manufacturers
have been able to include in them. In fact, we think that they have attempted
too much; in our view, the labels of the containers should contain in large
letters the words "Deadly Poison" short statements of the dangers and
precautionary measures to be taken, and a minimum statement of the purposes
for which the product is to be used. It is useless and dangerous to print
so much material on a label that a man cannot readily understand its vital
message when he has read it once. We: think it important that the labels
should be of a permanent kind.

10

49. DNC is a bright yellow substance which would readily discolour a
white garment. The organo-phosphorus insecticides are colourless, and we
think that a strong colour should be introduced during manufacture so that
discoloration of the overalls would be recognized as a clear warning of con-
tamination. There would be some advantage in having a common colour
for all these dangerous compounds.

50. We consider that the manufacturers of containers should give special
attention to the design of the spouts to guard against the danger of splashing
when the liquid compound is poured into the spray tank.

Enforcement

51. The Gowers Committee on Health, Safety and Welfare in Non-
Industrial Employment in their Report (Cmd, 7664) recommended that there
should be a statutory requirement that protective clothing should be provided
where scheduled substances were used. The Trades Union Congress repre-
sented in their evidence that the measures introduced for the protection of the
worker should be enforced by regulation.

52. We have given very careful consideration to this view. While the
dangers to man of the dinitro and organo-phosphorus compounds have not
yet been fully assessed, we consider that the medical evidence recorded in
section 6 of our report, including the fatalities which have occurred in this
country from the use of DNC, and those which have occurred in other countries
from the large-scale use of parathion, justify the introduction of statutory
measures for the protection of agricultural workers. We consider that statutory
backing should be given to the provision of protective clothing and washing
facilities and the labelling of containers, and that the provisions should be
supported by inspection by an officer of the Agricultural Departments or other
appropriate authority. Some of our proposals relate to conduct rather than
to devices ; for example, that the men should not eat or drink. in the spraying
area, and that they should make use of the protective clothing provided. It is
for this reason that proper supervision is very important. We consider that
the worker should accept some of the responsibility for his own safety and
that, if no other course will serve, the careless worker should be protected
from his own carelessness by being transferred permanently to other work.

XI. RECOMMENDATIONS

53. The following are our recommendations;

(i) Protective Clothing
    The complete list of protective clothing should comprise : overall of white
cotton or similar material, fastening at the neck and wrists ; a white cloth
hood to cover the head and the back and side of the neck; rubber coat;
rubber apron ; rubber gloves ; rubber boots; eye-shield ; respirator ; and
sou'wester.

    The following items should be worn on the various operations :

MIXING     Overall ; rubber boots ; rubber apron ; rubber gloves

When mixing takes place indoors, a respirator should
also be worn ; an eye-shield should be sufficient when
the mixing is done out of doors.

11

SPRAYING :        Crops : Overall ; hood ; eye-shield ; rubber boots ;

rubber gloves.
Trees : As for crops, except that a sou`wester and
rubber coat should be worn in place of overall and hood.

GREENHOUSE :   If the manufacturers' instructions regarding the use of
smoke generators in greenhouses are followed, and the
operator avoids inhaling the fumes during ignition and
adequately ventilates the greenhouse before re-entering
he need not wear protective clothing, but he should
carry a respirator at the ready position. If, however,
the operator should have to enter a greenhouse while
poisonous smoke or spray is present, he should wear
overall, hood, rubber boots, rubber gloves, and a
respirator of the full-face type. Workers applying sprays
in greenhouses should be similarly equipped.

TRACTOR SPRAYING :  With air-conditioned cab, the driver should wear overall
and rubber boots.
Without air-conditioned cab, the driver should wear
overall, hood, rubber boots, rubber gloves, and an
eye-shield.
The worker riding on the sprayer in order to attend
To the spray nozzles should wear overall, hood, rubber
coat, rubber gloves, rubber boots, and an eye-shield.

    A list of the protective clothing needed for each operation should be available
for reference by both employer and employee.
    The overall and hood should be taken off for laundering, and a new or
laundered set provided, when they have become noticeably contaminated
by the spray. Even if not noticeably contaminated, the overall and hood
should be changed at the end of a week‘s work.
    The workers should remove all their protective clothing at the end of the
spraying operations. On no account should they wear any part of it when
they leave the farm at the end of the day's work.

(ii) Tractor Cabs

   The evidence regarding gas-proof, air-conditioned cabs was not sufficiently
conclusive to enable us to make a general recommendation about the advantages
or disadvantages of this form of protection. Where such cabs are used we
recommend, however, that their protective properties should be frequently
tested. We understand that a reliable test would consist of releasing the
vapour of a lachrymator (tear-gas) such us ethyl-iodo-acetate into the air
intake of the charcoal filter.

(iii) Washing Facilities

   Soap, clean towels, and clean water should be provided near the scene of
Spraying Operations but sufficiently removed to avoid any contamination from
spray drift.
    Running water should be used if available. Alternatively, clearly marked
separate containers should be provided for washing (a) rubber boots, gloves.
etc. ; (b) the face and hands.

12

(iv) Working periods
    No worker engaged on spraying operations should work more than 10 hours
a day nor more than 6 days a week.
   No worker should be engaged on spraying operations while he is suffering
from a minor complaint such as a cold, bronchitis, or stomach upset.

(v) Supervision

    Every person employing workers on the agricultural use of dinitro or organo-
phosphorus compounds should be required to make proper arrangements for
their supervision and instruction.

(vi) Meals

    All workers engaged on spraying operations should be forbidden to eat or
drink in the spraying area, or to smoke while on their work.

(vii) De-contamination of Machinery and Equipment

   Spraying machines, hoses and spray-lances should be washed with water
before repairs are made, and at the end of each shift ;tanks and containers
should be washed thoroughly at the end of each shift.

    In no circumstances should the workers clear blocked jets by blowing out
with the mouth.

(viii) Warning to Local Doctors

   The Ministry of Agriculture and Fisheries should consult the British Medical
Association about the practicability of medical practitioners being circularized
by the Association about the dangers and appropriate treatments.
   Medical practitioners and hospitals should be warned when spraying opera-
tions are to be undertaken on farms in their vicinity.

(ix) Manufacturers' Responsibilities

LABELS :    The labels of containers should be required to show the

words " Deadly Poison " in large, clear type, a concise
statement of the dangers and precautions to be taken
antidotes where known and a minimum indication of
the purposes for which the product is to be used.
The labels should be of a permanent kind. Manufac-
turers' instructions about the control of pests and weeds,
should be given separately from the main label, e.g., in
the form of a wrapping leaflet.

COLOURING OF         Organo-phosphorus formulations should be coloured
MATERIALS                 preferably with one distinctive colour during manu-
facture

NOTIFICATION OF              In view of the need to inquire into such precautionary
NEW PREPARATIONS         measures as might prove necessary, the Agricultural
Departments should satisfy themselves that their
arrangements with industry are adequate to obtain prior
information about chemical compounds which the
manufacturers propose to release as insecticides and
weedkillers.

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(x) Instruction

    The Agricultural Departments should institute arrangements for the thorough
education of all concerned in the dangers of the chemical compounds and in
the precautionary measures to be taken, and should enlist the co-operation in
this work of the organizations shown in Section IV, Para. 4. of our report.

(xi) Research

    The Medical Research Council, in co-operation with other research or
investigating bodies, should be asked to carry out research into protective
devices, in an effort to discover a material which will give complete protection
against DNC and organo-phosphorus sprays, without interfering; with the
comfort and working capacity of the wearer.

   The Ministry of Supply should be asked to promote research with the object
of producing a lightweight respirator which will give complete protection against
inhalation of DNC and parathion dusts, fumes and smokes.

    The Agricultural Research Council should be asked to undertake experiments
to discover insecticides and weedkillers which are fully effective in their agricul-
tural purposes without being toxic to man.

54. Having considered the Report of the Gowers Committee (Cmd.7664),
and having reached the conclusions recorded under "Enforcement " in
Paras. 51 and 52 of our report, we advise that certain of our recommendations
should become the subject of statutory regulation. We consider that all the
protective measures recommended in Para. 53 (i), (iii), (v),(vi), and in
Para. 53 (ix) as to labelling, should be given legal effect, and that the Agricul-
tural Departments should have power, where appropriate, to enforce them by
inspection. We also consider that the Departments should have power both
to limit the duration of exposure of operatives to risk of contamination, on the
lines of the recommendation in Para. 53 (iv), and to schedule chemical
compounds for the purpose of the legislation.

55. While the institution of an elaborate system of inspection would not be
practicable, we feel that there should be a power of enforcement and that
test checks should be made from time to time to ensure that the protective
clothing is provided and is worn, that washing facilities are provided and are
used, and that meals are not consumed on the scene of spraying operations.
Some of the statutory measures we have recommended would impose legal
obligations on the worker as well as on the employer ; we note that this would
he in accordance with the principle embodied in the Factories Act, l937.

56. We recommend that adequate arrangements should be made for the.
protection of the workers who will he engaged in the agricultural use of DNC
and organo-phosphorus compounds during the spraying season which will
commence in the early spring of this year. We feel sure that the necessary
arrangements could be made through the collaboration of all the parties
concerned. even though it may be impracticable for our proposals to be fully
examined, and, if accepted, for legislation to be put forward in time.

57. In the course of our inquiry, we have found that the public may be
exposed to some risk to health arising from the agricultural use of dinitro and
organo-phosphorus compounds and we have been asked by the Ministers of

14

Agriculture and Fisheries, Food, and Health, and the Secretary of State for
Scotland, to investigate this risk. The chief danger lies in the chronic effects
which result from frequent exposure to these chemicals, and this greatly reduces
the hazard to the general public since normally they are not so exposed. There
are, however, certain precautions which should obviously be taken in the
public interest, We recommend these in advance of any further advice which
we may put forward at the end of the second part of our inquiry, namely :

   (xii) Spraying operations should be suspended in windy weather, particularly
on land adjacent to public roads; or footpaths.

   (xiii; Warning notices should be placed on gates giving access to fields
that are being, or have recently been, sprayed.

   (xiv) Surplus spraying material should be safely disposed of to avoid any
possible contamination of ponds or streams.

   (xv) Farm animals should be kept away from spraying operations and
from fields that have recently been sprayed.

   (xvi) To minimize adverse effects on pollination, beekeepers should be
warned before spraying operations are started on neighbouring farms.

58. There is no legal prohibition on the sale of dinitro and organo-
phosphorus formulations to the general public and we consider that in view of
the dangers associated with the ignorant or inexperienced use of these chemicals,
the sale to the public of formulations containing them should be brought under
statutory control. We think that such control would be in the interests of the
trade, as well as of the public. We, therefore, recommend :

   (xvii) That the retail sale of dinitro and organo-phosphorus compounds, other
than winter washes made up in small concentrations, should be restricted to
Chemists. This would not prevent farmers who wish to buy their supplies by
retail from doing so.

   

Signed on behalf of the Working Party,

S. ZUCKERMAN

Chairman

January, l951

15

APPENDIX

RELATIVE EFFICIENCY OF DIFFERENT HERBICIDES

Extract from Advice Leaflet No. 315 issued by the Ministry of

Agriculture and Fisheries.


  AMOUNT OF MATERIAL PER 100 GAL OF SPRAY SOLUTION PER ACRE

Sulphuric
Acid
Gal
Copper
Chloride
lb
DNOC
lb
MCPA
lb
DCPA
lb
Yellow Charlock
Pennycress
Treacle Mustard
White Charlock
Corn Buttercup
Shepherd's Needle
Corn Poppies
Fat Hen
Goosefoot or Orache
Mayweeds
Chamomile
Corn Marigold
Cleavers
Knotgrass
Willow Weed
Hemp Nettle
Annual Nettle
Spurrey
Speedwells
Bearbind
Chickweed
Cornflower
Parsley Piert
Fumitory
Shepherd's Purse
7-10***
7***
10***
13**
13*
15*
R
12W**
12W**
13W*
13W*
13W*
10***
13W*
13W*
10***
10W***
10***
10***
10***
13**
(13W)*
(13W)***
R
10W***
10-15***
15***
20***
20-30**
R
R
R
R
R
R
R
R
20-30*
R
20-30*
20-30**
(2.0)*
20*
20**
20-30***
R
R
R
R
(30)**
6-8***
4-6***
5-7***
8**
8*
8*
6-8W***
6-8***
6-8***
6-8***
6-8***
8W***
6-8**
8*
8*
6-8***
6-8**
6-8W**
6-8**
6-8**
8*
(8W)**
(5-7)***
6-8W***
7**
0·5-1·0***
0·75***
1·5***
2·0***
1·5-2·0***
2·0**
2·0*
2·0**
2·0**
R
R
R
R
R
2·0*
2·0**
(2-0)*
2·0*
R
2·0*
R
(2·0)***
R
R
2·0**
1·0***
(1·0)***
(l·5)***
2·0***
2·0***
2·0**
2·0*
2·0**
2·0**
R
R
R
R
R
(2·0)*
(2·0)**
(2·0)*
(2·0)*
(R)
2·0*
(R)
?
?
(R)
?

*** = over 90 per cent kill expected, ** Over 80 per cent, * over 50 per cent.
R = weed resistant.
W = wetting agent should be added to spray solution
( ) = figures are tentative
? = information is not yet available.

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Ends