OMC 586
File No: NA/14
9 July 1992
NATIONAL INDUSTRIAL CHEMICALS NOTIFICATION
AND ASSESSMENT SCHEME
FULL PUBLIC REPORT
OMC-586
This Assessment has been compiled in accordance with the
the Industrial Chemicals (Notification and
provisions of
Assessment) Act 1989 and Regulations. This legislation is an Act
of the Commonwealth of Australia. The National Industrial
Chemicals Notification and Assessment Scheme (NICNAS) is
administered by Worksafe Australia which also conducts the
occupational health & safety assessment. The assessment of
environmental hazard is conducted by the Department of the Arts,
Sport, the Environment, Territories and Tourism and the
assessment of public health is conducted by the Department of
Health, Housing and Community Services.
For the purposes of subsection 78(1) of the Act, copies of this
full public report may be inspected by the public at the Library,
Worksafe Australia, 92-94 Parramatta Road, Camperdown NSW 2050,
between the hours of 10.00 a.m. and 12.00 noon and 2.00 p.m. and
4.00 p.m. each week day except on public holidays.
Please find enclosed order form for Full Public Reports.
For Enquiries please contact Ms Mai Le at:
Street Address: 92 Parramatta Rd Camperdown, NSW 2050, AUSTRALIA
Postal Address: GPO Box 58, Sydney 2001, AUSTRALIA
Telephone: (61) (02) 565-9466 FAX (61) (02) 565-9465
Director
Chemicals Notification and Assessment
NA/14
FULL PUBLIC REPORT
OMC 586
1. APPLICANT(S)
Henkel Australia Pty. Ltd., 83 Maffra Street, BROADMEADOWS, VIC.,
3074.
2. IDENTITY OF THE CHEMICAL
Trade name: OMC 586
Type of Chemical: OMC 586 is a mixture of fatty acid
esters
Other name(s): Petrofree, Terradril 586, Synthetic oil
No. 2
Molecular weight: Average molecular weight = 312
(calculated from esterification number)
Methods of detection and determination:
OMC 586 can be identified from its Infra-red spectrum (see
below).
Spectral data:
The infra-red spectrum of OMC 586 shows clearly defined
absorption peaks at the following wavenumbers (cm-1):
725, 1120, 1175, 1380, 1465, 1740, 2830, 2860.
3. PHYSICAL AND CHEMICAL PROPERTIES
Appearance at 20癈 and 101.3 kPa:
OMC 586 is a clear, colourless-to-slightly-yellow liquid.
Odour: Not stated in notification package.
FULL PUBLIC REPORT 2
Melting Point: Below -15癈
Approximately 340oC
Boiling Point:
860 kg/m3 {for density}
Density:
342oC
Vapour Pressure: 100 kPa at
259oC
10 kPa at
196oC
1 kPa at
147oC
0.1 kPa at
6 x 10-3 kPa 100oC
at
8 x 10-5 kPa 45oC
at
4.5 x 10-5 kPa 38oC
at
Water Solubility:
< 5ppm by OECD TG 105 (1). The solubility of individual
components would be expected to be well below
this figure.
Partition Co-efficient: log Po/w > 4 (calculated)
(n-octanol/water)
Hydrolysis as a function of pH:
Ester hydrolysis takes place slowly in mud (<1% in 1 year) but
more rapidly when the drilling mud is dispersed in water.
Adsorption/Desorption: Not determined
Dissociation Constant: The esters do not dissociate
Flash Point: 179癈
Autoignition Temperature: 240癈
Flammability limits: Lower flammability limit =0.2%
(v/v)
Approximately (estimate)
Upper flammability limit = 2% (v/v)
approximately (estimate)
Pyrolysis products: Not determined
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Explosive Properties: Not determined
Reactivity/Stability: Not determined
Particle size distribution: Not applicable to a liquid
4. PURITY OF THE CHEMICAL
Degree of purity: approximately 99%
Toxic or hazardous impurities:
. Chemical name: 2-ethyl-1-hexanol
CAS No.: 104-76-7
Weight percentage: 0.5%
Toxic properties: Moderate irritant, also produces birth
deformities (including hydronephrosis,
tail and limb defects) in rats at oral
doses of 812 mg/kg and 1.62 g/kg (2)
Non-hazardous impurities:
. Chemical name: p-toluenesulfonic acid
CAS No.: 104-15-4
Weight percentage: 0.005%
. Chemical name: fatty acids
Weight percentage: 0.5%
5. INDUSTRIAL USES
OMC 586 will be used as the carrier fluid in an oil-based
drilling fluid (mud) for on-shore and off-shore oil and gas
drilling, especially for deviated holes and when drilling through
difficult geological formations. The fluid is circulated in the
drill hole to remove drill cuttings and stabilise the hole. Drill
cuttings are subsequently strained out of the fluid. Large
volumes of fluid are required because of the size of such
operations.
The liquid phase of the final mud system will contain 50 - 90%
OMC 586 plus water, emulsifiers, solids and other materials to
achieve the desired properties. Formulation of the mud may occur
at specialized mud plants, or at the drilling site. The notifier
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has indicated that initially the mud is expected to be produced
at one mud plant and three drilling sites. This will later expand
to up to four mud plants and twenty-one drilling sites.
Import volumes for OMC 586 are:
First year 750 kL (645 tonnes)
Second - fifth year 1113 kL (960 tonnes)
6. OCCUPATIONAL EXPOSURE
The notifier has indicated that a maximum of 50 workers, being
engineers, drilling crew, mud loggers and geologists, will have
the potential for exposure to OMC 586. Exposure time per woker
may vary from less than an hour a few days per year to
intermittent exposure over a shift for more than 30 days per
year.
Potential worker exposure at a mud plant would most likely occur
through skin contact while handling, sampling and testing OMC 586
or the formulated mud. Mud plants feature a pit or container for
mixing the components of the mud, a process which requires
extremely high shear forces. Inhalational exposure of workers
near these mixing processes should not be significant since OMC
586 is not highly volatile, and since the formation of respirable
mists during the mixing process is unlikely.
The potential for worker exposure at drilling sites would be
similar to that at mud plants, with even less chance of
inhalational exposure since the substance will be used in the
open where any vapours or mists are more readily dispersed.
However since mud will be applied to the drilling process and
later recovered, there would be greater opportunity for skin
contact.
7. PUBLIC EXPOSURE
The potential for public exposure to OMC 586 appears negligible.
This substance is a blend of fatty acid esters of low volatility
and is used exclusively as a constituent of a drilling 'mud' in
on-shore and off-shore oil and gas drilling. The notifier has
indicated that 'small amounts' will be released from drilling
holes to the environment but this is not likely to have any
impact on public health.
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The notifier has indicated that the product is to be imported to
Australia `for the time being'.
The information supplied indicates that OMC 586 is stored in
steel drums and is transported by tank cars. The notifier has
indicated that no special regulations for transportation of OMC
586 apply. Disposal is by incineration (>1200oC).
8. EVALUATION OF TOXICOLOGICAL DATA
8.1 Acute Toxicity
8.1.1 Acute Oral Toxicity in Rats (3)
This acute oral toxicity study was conducted according to OECD
Test Guideline No. 401. Five male and five female Wistar rats
received a single oral dose, by stomach tube, of OMC 586
(technical grade) suspended in arachidis oil. Following a 14 day
observation period, surviving animals were sacrificed and
necropsied.
No mortalities occurred and no signs of intoxication were
recorded. Necropsy was unremarkable. The LD50 was >2000 mg/kg.
8.1.2 Skin Irritation in Rabbits (4)
0.5 ml of undiluted OMC 586 was applied to the shaved, intact
dorsal skin of 4 male rabbits. The dorsal area was covered by an
inert plastic wrap and gauze bandage for a 4 hour period. Any
symptoms were reported over a 7 day period.
Slight erythema persisted to 72 hours in all four rabbits, while
the slight oedema seen in two rabbits at one hour had resolved by
48 hours. No symptoms were evident at 7 days. The compound was
classified as a slight skin irritant.
8.1.3 Human Skin Compatibility (Open Epicutaneous Test) (5)
OMC 586 at concentrations of 50% (in paraffin perliquid) or 100%,
was applied to the inner forearm surface of 10 male and female
human volunteers. One to two drops of the test compound was
applied every 30 seconds for up to 60 minutes. Pure paraffin
perliquid also served as a negative control.
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No subjective or objective reactions were reported after 60
minutes of application of either concentration of the test
compound.
8.1.4 Human Skin Compatibility (Closed Epicutaneous Test)(6)
OMC 586, at concentrations of 25%, 50% or 100%, was applied
dermally on the back of 20 healthy male and female human
volunteers and held under an occlusive patch for a period of 24
hours. Paraffin perliquid, demineralised water, physiological
saline, SDS 0.5%. AS and Texapon N25 1.0% AS served as reference
substances. Cutaneous responses were evaluated at 6, 24, 48 and
72 hours after patch removal.
No skin reaction was reported at the 25% or 50% dilutions.
Mainly slight erythema was seen with the undiluted compound, with
an apparent smaller incidence of moderate erythema and slight
oedema. However, the number of individuals reacting, the time
course involved and the reversibility or otherwise of reactions
is unclear from the data provided.
8.1.5 Skin Sensitisation in Guinea Pigs (7)
Thirty Pirbright white guinea pigs were used in the maximisation
test to assess the sensitising potential of OMC 586. Preliminary
studies indicated that 0.5% and 40% of OMC 586 in paraffin oil
were the minimally irritating concentrations following
intracutaneous and epicutaneous induction respectively. These
concentrations were therefore used for the induction phases. A
20% solution of OMC 586 was used for the challenge phases in both
treated and control animals. Exposure chambers were employed for
epicutaneous exposures in the challenge phase.
One treated animal died after the first induction treatment.
Slight erythema was seen in 7/20 treated animals at 1 hour
following the intracutaneous induction and in 11/20 animals at 24
hours post injection. No effects were seen in controls. After
epicutaneous induction, slight to moderate erythema and/or oedema
was recorded in 16/19 treated animals and 7/10 control animals.
At 24 hours, effects were generally weaker and were seen in 10/19
treated and 2/10 control animals. One treatment animal revealed
slight erythema 24 hours after the challenge application, while a
slight skin reaction was recorded in 5/10 control animals. No
effects were evident in treated animals at 48 hours, while slight
erythema persisted in one control animal. These results indicate
FULL PUBLIC REPORT 7
that OMC 586 has no sensitising potential under the test
conditions.
8.1.6 Toxicology review of constituent fatty acid ester
The notifier submitted a review paper on a fatty acid ester which
is a constituent of OMC 586. The following acute toxicological
properties were reported for this substance.
An acute oral LD50 in rats of >55 g/kg was estimated from 3
separate studies. No mortalities were reported in any study and
the only signs were slight ocular haemorrhage and moderate
diarrhoea at 55 g/kg.
In a 24 hour dermal exposure study in rabbits, at doses up to 8.1
g/kg, the only reported effect was mild skin irritation which had
fully resolved by day 10.
The substance was classified as a mild skin irritant in a rabbit
study. Results of 2 other rabbit studies demonstrated a lesser
irritant effect. Reported results of 3 separate Draize rabbit
eye irritation studies, indicated that the substance is minimally
irritating to the rabbit eye. In two separate studies, the
substance was reported as non-senstising in guinea pigs, using
the Landsteiner and Jacobs technique.
In a 48 hour occlusive patch test and an 18-day repeated patch
test conducted in humans, no dermal irritant effects were
reported. Mild irritation was noted in some volunteers in a 21-
day repeat patch test in humans, with a 42% formulation.
8.2 Repeat Dose Studies
8.2.1 28 Day Repeat Dose Oral Toxicity in Rats (8)
Groups of five male and five female Sprague-Dawley rats were
dosed daily by oral gavage, with OMC 586 in corn oil, at dose
rates of 0, 100, 300 or 1000 mg/kg bw 5 days/week for 28 days.
Signs of intoxication, food consumption and body weights were
monitored and recorded. Haematological and biochemical analyses
were performed on samples taken prior to study initiation and at
study termination. Neurotoxicological assessment was also
performed at periodic intervals throughout the study. At
termination, the surviving animals were necropsied and selected
tissues were sampled for histological examination.
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No mortalities or signs of intoxication were recorded at any dose
level. A statistically significant decrease in platelet count
and increase in lymphocyte count, coupled with a decreased
neutrophil count in low dose males.Because these responses were
not dose-related they were considered not to be toxicologically
significant. Clinical chemistry analysis revealed no
toxicologically significant findings. Necropsy, organ weight
analysis and histopathological analysis revealed no treatment-
related effects.
8.3 Genotoxicity
8.3.1 Salmonella/Mammalian Microsome Mutagenicity Test (9)
The mutagenic potential of OMC 586 was assessed using histidine
dependent auxotrophic mutants of Salmonella typhimurium (TA 98,
TA 100, TA 1535, TA 1537, TA 1538), in the presence or absence of
metabolic activation (Aroclor 1254 induced rat liver S9 mix).
Two independent assays were performed. OMC 586 was suspended in
Tween 80/bidistilled water, at concentrations of 8-5000 ug/plate.
Sodium azide (TA 100, TA 1535), 9-aminoacridine (TA 1537) and 4-
nitro-o-phenylendiamine (TA 98, TA 1538) served as the positive
controls without activation. 2-aminoanthracene served as the
positive control in the presence of activation in all strains.
No significant increase in the mean number of revertant colonies
was seen at any dose level of OMC 586 compared with the negative
controls in the presence or absence of metabolic activation. The
positive controls confirmed the sensitivity of the assay. OMC
586 is therefore not considered to be mutagenic under the
conditions of this assay.
8.3.2 Rodent Bone Marrow Microucleus Test (10)
Groups of five male and five female CD-1 mice received a single
ip dose of OMC 586 in corn oil (50/50 v/v) at 1.25, 2.5 or 5
ml/kg bw. Vehicle controls were also employed. Cyclophosphamide
served as the positive control (30 mg/kg). Groups of 5
animals/sex/dose level were sacrificed at 24, 48 and 72 hours
post dosing. Positive control animals were sacrificed 24 hours
post dosing. Bone marrow smears were obtained from the excised
femur, stained and the numbers of micronucleated polychromatic
erythrocytes were assessed.
FULL PUBLIC REPORT 9
No signs of intoxication were reported. No increase in the mean
number of micronucleated erythrocytes was seen at any dose level
of OMC 586 when compared to the negative control marrow smears at
any time point. No treatment related effect on polychromatic
erythrocyte production was noted. The positive control confirmed
the sensitivity of the assay. OMC 586 is not considered to be
mutagenic under the conditions of the assay.
8.4 Overall Assessment of Toxicological Data
OMC 586 has low acute oral toxicity and is a slight skin irritant
in rats. OMC 586 was not a skin sensitiser in guinea pigs. When
undiluted OMC 586 was held in contact with human skin for 24
hours, it produced slight to moderate erythema and slight odema.
OMC 586 was not genotoxic in either a Salmonella/mammalian
microsome mutagenicity test or a mouse bone marrow micronucleus
test. A 28-day repeat dose toxicity study showed that OMC 586 has
low systemic toxicity.
A constituent ester of the OMC 586 fatty acid ester blend, showed
a similar toxicological profile to that summarised for OMC 586
above, and additionally was slightly irritating to the rabbit
eye.
It is expected that OMC 586 would be metabolised via hydrolysis
to its constituent fatty acids and alcohol. These metabolites
would then be further metabolised, but their fate cannot be
predicted.
Acute dermal toxicity, acute inhalational toxicity, and eye
irritancy test reports were not supplied by the notifier, and
were granted a Variation of Schedule Requirements.
The rationale for granting the Variation on acute dermal toxicity
was:
. that no acute toxic effects were produced in rats by a fatty
acid ester (structurally typical of the mixture of fatty
acid esters comprising OMC 586) which is a constituent of
OMC 586 at high dermal doses of up to 8.1 g/kg;
. that esters of fatty acids with lower alcohols (including
methyl caproate, pentyl caproate, and n-hexyl caprylate),
which are structurally related to the constituents of OMC
FULL PUBLIC REPORT 10
586, have low acute dermal toxicity (all having dermal LD50
values in rodents of > 5 g/kg) (11); and
. that OMC 586 otherwise showed low overall toxicity (low
acute oral toxicity, no treatment-related effects in a
repeat-dose oral toxicity test, and no genotoxic effects).
On the basis of the above information, there are reasonable
grounds for assuming that OMC 586 will have low acute dermal
toxicity.
The rationale for granting the Variation on acute inhalational
toxicity was:
. that OMC 586 is not highly volatile and the notified pattern
of use indicates that inspirable and/or respirable mists of
OMC 586 will not be formed; and
. that esters of fatty acids with lower alcohols (methyl
capronate and isopropyl palmitate), which are structurally
related to the constituents of OMC 586, have low acute
inhalational toxicity (LC50 values in rodents of 14 g/m3/2h
and >200 g/m3/h, respectively) (11).
On the basis of the above information, there are reasonable
grounds for assuming that OMC 586 will have low acute
inhalational toxicity.
The rationale for granting the Variation on eye irritation tests
was:
. that a fatty acid ester which is a constituent of OMC 586 is
known to be a slight eye irritant; and
that OMC 586 was found to be non-irritating in an in vitro
.
assay using the chick chorioallantoic membrane, details of
the validation of which (against the Draize test in rabbits)
are published (12,13).
On the basis of the above information, there are reasonable
grounds for assuming that OMC 586 will be a slight eye irritant.
Consistent with skin and eye irritation, OMC 586 can also be
considered a possible respiratory tract irritant.
FULL PUBLIC REPORT 11
It should also be noted that one of the impurities, 2-ethyl-1-
hexanol present at 0.5%, was investigated in a rat teratology
study (2). Birth deformities (including hydronephrosis, tail and
limb defects) were produced in offspring at oral doses of 2-
ethyl-1-hexanol of 812 mg/kg and 1.62 g/kg.
9. ASSESSMENT OF ENVIRONMENTAL EFFECTS
9.1 Environmental Release
. Volume
Imports will be high at 645 - 960 tonnes per annum over the next
five years.
. Formulation, handling and disposal
Mud formulation will take place initially at a fully bunded
liquid mud plant at Dampier, licenced by the WA EPA, and later at
the drilling site. Future mud plants may be constructed in
Victoria to service the oil and gas fields in Bass Strait and the
Otway Basin, with production expanding to as many as four plants
and twenty-one drilling sites. The notifier indicates that any
spills at Dampier will either be recycled or disposed of at a
designated waste disposal site in accordance with licence
conditions.
The mud will basically be a dense colloid slurry of barite
(barium sulphate) in OMC 586 and water, with smaller amounts of
emulsifiers, surfactants, viscosifiers, fluid loss agents and
lime added to achieve a water in oil emulsion with the required
properties. Blending will take place in surface pits.
. Use
OMC 586 will constitute the carrier fluid in oil-based drilling
muds, which lubricate and cool drilling operations, stabilise the
drill hole by creating an impermeable lining, and serve as a
medium for removal of drill cuttings. Wells are drilled using a
rotating bit turned by a hollow shaft through which the drilling
mud is pumped more or less continuously, returning to the surface
with suspended cuttings through a mud return line (14). The
notifier indicates that used mud will be returned to the mud
plant for reconditioning, where cuttings will be strained out for
FULL PUBLIC REPORT 12
disposal in a designated waste disposal site. Literature reports
indicate that drill cuttings are typically discharged to form
piles around the drilling site in North Sea operations (15) using
low toxicity base oils (parrafins and saturated cyclic compounds)
and on the US outer continental shelf (16).
9.2 Environmental Fate
It would appear that most of the OMC 586 will be disposed of to
landfill when drill cuttings or mud which cannot be recycled ,
for example because of excessive colloidal solid content, are
disposed of. While the terrestrial fate of OMC 586 has apparently
not been investigated, as a mixture of fatty acid esters it can
be expected to sorb to soils and undergo chemical or microbial
hydrolysis followed by mineralisation. Hydrolysis is more likely
to be initiated microbially as the esters proved stable in
formulated mud systems (approximately 1% hydrolysis in one year)
and did not undergo significant hydrolysis under field conditions
(23 days at bottom hole temperatures of 120-140oC.
The notifier states that drilling muds containing OMC 586 will be
returned to the mainland for recycling or disposal. While
significant amounts should not enter the marine environment under
normal conditions, accidents at sea during transport, or leaks
resulting from sudden oil and gas shows or well overflows during
drilling, may give rise to some exposure. Ready biodegradability
of OMC 586 in the marine environment was evaluated according to
established protocols in the closed bottle test using natural
seawater. The 5 day biological oxygen demand at concentrations of
0.5 and 2.5 ppm was 83 and 70% respectively, indicating that
biodegradation of the ester component of mud spills and leaks
should proceed rapidly after dispersion in seawater.
Release of OMC 586 to the marine environment will be followed by
partitioning between the sediment and the water column. Anaerobic
degradability was determined by the ECETOC method (No 28, 1988)
which involves measurement of net gas production and dissolved
inorganic carbon formation from a mineral salt solution
innoculated with secondary digester sludge from a municipal
sewage treatment plant. Based on gas production, which steadily
increased to reach 63% of theoretical in 35 days, the first half-
life was about 3 weeks. Inclusion of dissolved inorganic carbon
increased the measured extent of biodegradation to 82%,
indicating that OMC 586 would not be expected to persist under
the anaerobic conditions characteristic of marine sediment.
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In summary, the structural features and experimental performance
of OMC 586 indicate that it should be readily biodegraded in both
terrestrial and marine environments. Bioaccumulation is not
envisaged as the esters are readily hydrolysed.
9.3 Environmental Effects
Results for the following are available:
-------------------------------------------------------------
Test Species Result
-------------------------------------------------------------
96h exposure (base oil) Brown Shrimp
(Crangon crangon) LC50 > 10000ppm
96h exposure (mud) " LC50 > 32000ppm
Growth inhibition(72h) Alga (Skeletonema
costatum) EC50 = 15800ppm
Retardation of
sedimentation and
metamorphosis (240h) Acorn barnacle
(Balanus improvisus) EC50=125000ppm
Growth inhibition
(120h) Blue mussel
(Mytilus edulis) EC50 = 5.6ppm
-------------------------------------------------------------
The toxicity of base oil to brown shrimp was investigated under
semi-static conditions, with surface slicks skimmed off and
recirculated through the test medium as fine droplets. In the mud
test, mud was allowed to settle evenly over the tank floor before
addition of the shrimp. Thus the exact concentrations to which
the shrimp were exposed are unclear, but it appears unlikely that
mud spills will give rise to mortality of brown shrimp under
environmental conditions.
The remaining results were obtained in Norwegian tests and,
according to the test reports, indicate moderate toxicity of the
test substance (used mud). The exact concentrations to which the
algae and barnacles were exposed are unclear as test media were
filtered before use to allow sufficient light infiltration. The
FULL PUBLIC REPORT 14
mussel test was conducted in natural sea water with a
microencapsulated emulsion of the test substance (apparently the
ester rather than mud, although this is not clear). Substances
are regarded as being of moderate toxicity to mussels when the
EC50 is above 1ppm.
Acute toxicity test results were also provided for zebrafish
exposed under semi-static conditions to a fatty acid ester
(representative of the heavier fractions of OMC 586). No
significant acute toxicity was recorded (LC50>10000ppm). This
mixture of substances also proved nontoxic to bacteria when
tested according to OECD Guideline 209.
Toxic effects on marine biota from drilling muds have been
correlated with diesel oil, which is sometimes added to muds to
improve lubricity (16), and with levels of petroleum hydrocarbon
contaminants (17), particularly water soluble oil fractions (18).
By comparison, the toxicity of the ester appears relatively
insignificant.
9.4 Environmental Hazard
In contrast to North Sea drilling operations where cuttings are
discharged directly to the marine environment, cuttings from
Western Australian wells drilled using OMC 586 based muds will be
returned to the mainland for disposal. The exposure of the marine
environment to OMC 586, and to the more hazardous petroleum
contaminants which may form part of used mud systems, should be
restricted to leak and accident situations such as overflows or
loss of ships at sea.
As a mixture of esters, OMC 586 can be expected to be readily
metabolised through hydrolysis both in the environment and in
living organisms. The marine toxicological profile appears low,
exposure should be low, and accumulation and bioaccumulation are
not predicted. The environmental hazard from the proposed use of
OMC 586 appears low. Esters such as those which comprise OMC 586
would appear preferable on environmental grounds to hydrocarbon
lubricants which may prove more persistent and biaccumulative.
10. ASSESSMENT OF OCCUPATIONAL HEALTH AND SAFETY EFFECTS
OMC 586 is unlikely to cause significant effects on the health
and safety of workers exposed to this substance. OMC 586 has low
FULL PUBLIC REPORT 15
toxicity, producing slight skin irritation and probably slight
eye irritation.
If spilt onto smooth surfaces OMC 586 may make such surfaces more
slippery, which would increase the chance of worker slips and
falls.
11. ASSESSMENT OF PUBLIC HEALTH EFFECTS
The acute to short-term toxicity of OMC 586 is low, and the
potential for public exposure to OMC 586 appears to be
negligible. The product is a blend of fatty acid esters of low
volatility and is used exclusively as a constituent of a drilling
`mud' in on-shore and off-shore oil and gas drilling. In
conclusion, the use pattern outlined by the notifier and the
toxicological profile provided suggests that OMC 586 presents a
negligible public health hazard.
12. RECOMMENDATIONS
To minimise public, worker and environmental exposure to OMC 586
the following guidelines and precautions should be observed:
. copies of the Material Safety Data Sheet for OMC 586 should
be made available to all personnel who may have exposure to
the substance;
. spillages of OMC 586 should be cleaned up as soon as
possible to avoid causing slips and falls, for example by
covering with a suitable absorbent material and subsequent
disposal according to local regulations;
. to minimise environmental exposure to OMC 586, other States
where drilling is proposed should adopt similar standards to
those which apply in Western Australia; and
. mud formulation plant workers and drilling rig workers who
come into direct contact with drilling fluids containing OMC
586 should:
- avoid contact of OMC 586 with the skin by wearing
impermeable gloves (for example rubber or PVC gloves)
complying with Australian Standard AS 2161 Industrial
Safety Gloves (excluding electrical and medical gloves)
(19);
FULL PUBLIC REPORT 16
- avoid contact of OMC 586 with the eyes by wearing
safety glasses or goggles complying with Australian
Standard AS 1337 Eye Protectors for Industrial
Applications (20), and chosen and used in accordance
with Australian Standard AS 1336 Recommended Practices
for Eye Protection in the Industrial Environment (21);
and
- observe good personal hygiene practices at work.
13. MATERIAL SAFETY DATA SHEET
The Material Safety Data Sheet (MSDS) for OMC 586 is at
Attachment 1. This MSDS was supplied by Henkel Australia Pty.
Limited as part of their notification statement. The MSDS is
reproduced here as a matter of public record. The accuracy of
this information remains the responsibility of Henkel Australia
Pty. Limited.
14. REQUIREMENTS FOR SECONDARY NOTIFICATION
Under the Industrial Chemicals (Notification and Assessment) Act
1989 (the Act), secondary notification of OMC 586 shall be
required if any of the circumstances stipulated under subsection
64(2) of the Act arise. No other specific conditions are
prescribed.
15. REFERENCES
Organisation for Economic Cooperation and Development, Test
(1)
Guideline 105, OECD, Paris, 1981.
(2) Ritter,E.J., Scott,W.J.Jr, Randall,J.L., and Ritter,J.M.
Teratogenicity of di(2-ethylhexyl) phthalate, 2-
ethylhexanol, 2-ethylhexanoic acid, and valproic acid, and
potentiation by caffeine. Teratology, 35, 41-46, 1987.
(3) OMC 586 - Acute Oral Toxicity in Rats (Sterzel. W, Henkel,
Study no. HTX 890241, 1990)
(4) OMC 586 - Acute Dermal Irritation (Steiling W, Henkel, Study
no. HTX 890242, 1989)
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(5) Test on Skin Compatibility of OMC 586 in an Open
Epicutaneous Test after Burckhardt (Krachter, Henkel, study
no. HTX 900415, 1990)
(6) Test on Skin Compatibility of OMC 586 in a Closed
Epicutaneous Test (Krachter, Henkel, Study no HTX 900468,
1990)
(7) OMC 586 - Skin Sensitisation (Maximisation Method)
(Steiling. W, Henkel, Study no. HTX 900318, 1991)
(8) 28 Day Repeated Dose - Oral (Fitzgerald G, Toxilcon
Corporation, Project no 91G-0422, 1991)
(9) OMC 586 - Salmonella/Mammalian Microsome Mutagenicity Test
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(20) Standards Australia, AS 1337 Eye Protectors for Industrial
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FULL PUBLIC REPORT 19
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