Occupational Health Guideline for 

Mineral Oil Mist 

INTRODUCTION 

This guideline is intended as a source of information for 

employees, employers, physicians, industrial hygienists, 

and other occupational health professionals who may 

have a need for such information. It does not a<tempt to 

present all data; rather, it presents pertinent information 

and data in summary form. 

SUBSTANCE IDENTIFICATION 

• Formula: C.H,., where n = 16 and up 

• Synonyms: The mist of petroleum-based: white mineral oil; cutting oils; heat-treating oils; hydraulic oils; 

cable oil; transformer oil; lubricating oils; drawing oils 

• Appearance and odor: Mist with an odor like burned 

lube oil generated from petroleum-base or white mineral petroleum oil. 

PERMISSIBLE EXPOSURE LIMIT (PEL) 

The current OSHA standard for mineral oil mist is 5 

milligrams of mineral oil mist per cubic meter of air 

(mglm') averaged over an eight-hour work shift. 

HEALTH HAZARD INFORMATION 

• Routes of exposure 

Mineral oil mist can affect the body if it is inhaled. 

• Effects of overe:I)IOSure 

Inhalation of mineral oil mist may cause adverse respiratory effects. 

• Reporting signs and symptoms 

A physician should be contacted if anyone develops any 

signs or symptoms and suspects that they are caused by 

exposure to mineral oil mist. 

• Recommended medieal surveillance 

The following medical procedures should be made 

available to each employee who is exposed to mineral 

oil mist at potentially hazardous levels: 

1. Initial Medical Screening: Employees should be 

screened for history of certain medical conditions 

(listed below) which might place the employee a1 

increased risk from mineral oil mist exposure. 

-Chronic respiratory disease: In persons with impaired pulmonary function, especially those with obstructive airway diseases, the breathing of mineral oil 

mist might cause exacerbation of symptoms due to its 

irritant properties. 

-Skin disease: Prolonged exposure to mineral oil 

mist may cause a dermatitis. Persons with pre-existing 

skin disorders may be more susceptible to the effi'Ctl of 

this agent. 

2. Periodic Medical EZilminatilln: Any employee developing the above-listed conditions should be referred f<K 

further medical examination. 

• SII1IIJIUII"Y of tn:deology 

Inhalation of mineral oil mist in high concentratio111 

may cause pulmonary effects, although this has rarely 

been reported. A single case of lipoid pneumonitis 

suspected to have been caused by exposure to very high 

concentrations of oil mist was reported in 1950; thia 

occurred in a cash register serviceman, whose heavy 

exposure occurred over 17 years of employment; no 

other cases have been recorded. Experimental animal 

exposure studies to white mineral oil mist (Wltreated, 

and with no additions) for repeated daily IH!our exposures for 1 year at 5 mg!m• were entirely negative in all 

criteria used for measuring response. A similsr study at 

100 mg!m• resulted in some slight changes in some but 

not all species exposed; no histologic changes of significance were noted. Exposure to oil mist did not appear 

to accelerate the production of lung tumors in a lungtumor-susceptible strain of mice. A second parallel 

study of sulfurized, solvent-extracted naphthenic-bue 

oil to which animals were exposed daily at 50 mg!m.• 

for 18 months failed to reveal a single animal with aay 

sort of injury or indisposition as a result of the oil mist 

inhalation. A review of exposures to mineral oil mist 

averaging 15 mglm0 (but often higher) in several 

industries disclosed a striking lack of reported cases of 

illness related to these exposures. A study of oil mist 

These recommendations reflect good industrial hygiene and medical surveillance practices and their implementation will 

assist in achieving an effective occupational health program. However, they may not be sufficient to achieve compliance 

with all requirements of OSHA regulations. 

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES 

Public Health Service Centers lor Disease Control 

National Institute lor Occupational Safety and Health 

September 1871 

U.S. DEPARTMENT OF LABOR 

Occupational Safety and Health Administration 

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exposures in machine shops, at mean concentrations of 

3.7 mglm3 and maximum of 110 mglm3 , showed no 

increase in respiratory symptoms or decrement in respiratory performance attributable to oil mist inhalation 

among men employed for many years. There is no 

evidence to suggest any relation between in- halation of 

oil mist and lung cancer. On the other hand, there are 

some reported cases of skin cancer from contact with 

certain oils. Contact with liquid oils may cause dermatitis. 

CHEMICAL AND PHYSICAL PROPERTIES 

• Physical data 

I. Molecular weight: Not pertinent 

2. Boiling point (760 mm Hg): 360 C (680 F) 

3. Specificgravity(water = 1):0.8- 0.9 

4. Vapor density (air = I at boiling point of mineral 

oil mist): Not applicable 

5. Melting point: Very low 

6. Vapor pressure at 20 C (68 F): Very low 

7. Solubility in water, g/100 g water at 20 C (68 F): 

Insoluble 

8. Evaporation rate (butyl acetate = I): Not applicable 

• Reacti"rity 

I. Conditions contributing to instability: None 

2. Incompatibilities: None 

3. Hazardous decomposition products: None 

4. Special precautions: None 

• Flammability 

I. Flash point: 135 C (275 F) (closed cup) 

2. Autoignition temperature: 260- 371 C (500- 700 

F) 

3. Flammable limits in air, % by volume: Not applicable 

4. Extinguishant: Dry chemical, foam, carbon dioxide 

• Warnmg properties 

Mineral oil mist is not known to be an eye irritant. 

MONITORING AND MEASUREMENT 

PROCEDURES 

• General 

Measurements to determine employee exposure are best 

taken so that the average eight-hour exposure is based 

on a single eight-hour sample or on two four-hour 

samples. Several short-time interval samples (up to 30 

minutes) may also be used to determine the average 

exposure level. Air samples should be taken in the 

employee's breathing zone (air that would most nearly 

represent that inhaled by the employee). 

• Method 

Sampling and analyses may be performed by collection 

of mineral oil mist on a ftlter, followed by treatment 

with chloroform and analysis by fluorescence spectrophotometry. An analytical method for mineral oil mist 

is in the NIOSH Manual of Allalytica/ Methods. 2nd Ed .. 

2 Mineral 011 Mist 

Vol. 4, 1978, available from the Government Printing 

Office, Washington, D.C. 20402 (GPO No. 017-033-

00317-3). 

RESPIRATORS 

• Good industrial hygiene practices recommend that 

engineering controls be used to reduce environmental 

concentrations to the permissible exposure level. However, there are some exceptions where respirators may 

be used to control exposure. Respirators may be used 

when engineering and work practice controls are not 

technically feasible, when such controls are in the 

process of being installed, or when they fail and need to 

be supplemented. Respirators may also be used for 

operations which require entry into tanks or closed 

vessels, and in emergency situations. If the use of 

respirators is necessary, the only respirators permitted 

are those that have been approved by the Mine Safety 

and Health Administration (formerly Mining Enforcement and Safety Administration) or by the National 

Institute for Occupational Safety and Health. 

• In addition to respirator selection, a complete respiratory protection program should be instituted which 

includes regular training, maintenance, inspection, 

cleaning, and evaluation. 

PERSONAL PROTECTIVE EQUIPMENT 

• Employees should be provided with and required to 

use impervious clothing, gloves, face shields (eight-inch 

minimum), and other appropriate protective clothing 

necessary to prevent repeated or prolonged skin contact 

with liquid mineral oil. 

• Non-impervious clothing which becomes wet with 

liquid mineral oil should be removed promptly and not 

rewom until the mineral oil mist is removed from the 

clothing. 

SANITATION 

• Skin that becomes wet with liquid mineral oil should 

be promptly washed or showered with soap or mild 

detergent and water to remove any mineral oil mist. 

COMMON OPERATIONS AND CONTROLS 

The following list includes some common operations in 

which exposure to mineral oil mist may occur and 

control methods which may be effective in each case: 

September 1178 
Operation 

Use as a coolant or 

quenching agent in 

machine shop 

operations and metal 

fabrication; during 

coating and cleaning in 

foundry operations 

Use in steel rolling 

operations; use in 

lubricating and cleaning 

of machinery 

Use in pressroom 

operations in printing 

Use in mine drilling 

operations 

Use as an insecticide 

Controls 

Process enclosure; 

local exhaust 

ventilation; general 

mechanical ventilation 

Procass enclosure; 

local exhaust 

ventilation; general 

mechanical ventilation 

Mist suppression; local 

exhaust ventilation; 

general mechanical 

ventilation 

Process enclosure; 

local exhaust 

ventilation; general 

mechanical ventilation 

General dilution 

ventilation 

EMERGENCY FIRST AID PROCEDURES 

In the event of an emergency, institute first aid procedures and send for first aid or medical assistance. 

• Skin Exposure 

If skin becomes wet with mineral oil mist, wash the 

contaminated skin using soap or mild detergent and 

water. If mineral oil mist penetrates through the clothing, remove the clothing and wash the skin using soap 

or mild detergent and water. 

• Breathin11 

If a person breathes in large amounts of mineral oil mist, 

move the exposed person to fresh air at once. 

SPILL, LEAK, AND DISPOSAL 

PROCEDURES 

• Persons not wearing protective equipment and clothing should be restricted from areas of spills or releases 

until cleanup has been completed. 

• If mineral oil mist is released in hazardous concentrations, ventilate area of release to disperse the mist. 

• If mineral oil mist is spilled or leaked, the following 

steps should be taken: 

I. Ventilate area of spill orleak. 

2. For small quantities, absorb on paper towels. Evaporate in a safe place (such as a fume hood). Allow 

sufficient time for evaporating vapors to completely 

September 1871 

clear the hood ductwork. Bum the paper in a suitable 

location away from combustible materials. Large quantities can be collected and atomized in a suitable combustion chamber. 

• Waste disposal methods: 

Mineral oil mist may be disposed of: 

I. By absorbing it in vermiculite, dry sand, earth or a 

similar material and disposing in a secured sanitary 

landfill. 

2. By atomizing in a suitable combustion chamber. 

REFERENCES 

• American Conference of Governmental Industrial 

Hygienists: "Oil Mist (Mineral)," Documentation of the 

Threshold Limit Values for Substances in Workroom Air 

(3rd ed., 2nd printing), Cincinnati, 1974. 

• Deichmann, W. B., and Gerarde, H. W.: Toxicology of 

Drugs and Chemicals, Academic Press, New York, 

1969. 

• Ely, T. S., et al.: "A Study of Mortality, Symptoms, 

and Respiratory Function in Humans Occupationally 

Exposed to Oil Mist," Journal of Occupational Medicine, 

12:253-261, 1970. 

• Goldstein, D. H., et al.: "An Epidemiologic Study of 

an Oil Mist Exposure," Archives of Environmental 

Health. 21:600-603, 1970. 

• Grant, W. M.: Toxicology of the Eye (2nd ed.), C. C. 

Thomas, Springfield, Illinois, 1974. 

• Hendricks, N. V ., et al.: "A Review of Exposures to 

Oil Mist," Archives of Environmental Health. 4:139-145, 

1962. 

• Lippmann, M., and Goldstein, D. H.: "Oil-Mist Studies, Environmental Evaluation and Control," Archives of 

Environmental Health. 21:591-599, 1970. 

• Proudfit, J. P., et al.: "Chronic Lipid Pneumonia 

Following Occupational Exposure," A.M.A. Archives of 

Industrial Hygiene and Occupational Medicine, I: 105-

111,1950. 

• Stauden, A. (exec. ed.): Kirk-Othmer Encyclopedia of 

Chemical Technology (2nd ed.), lnterscience, New York, 

1972. 

Mineral on Mist 3 
RESPIRATORY PROTECTION FOR MINERAL OIL MIST 

Condition 

Particulate Concentration 

25 mg/m• or less 

50 mg/m• or less 

250 mg/m• or less 

2,500 mg/m• or less 

Greater than 2,500 mg/111" or 

entry and escape from 

unknown concentrations 

Fire Fighting 

Minimum Respiratory Protection• 

Required Above 5 mg/111" 

Any mist respirator, except single-use. 

Any mist respirator, except single-use or quarter-mask respirator. 

Any fume respirator or high efficiency particulate filter respirator. 

Any supplied-air respirator. 

Any self-contained breathing apparatus. 

A high efficiency particulate filter respirator with a full facepiece. 

Any supplied-air respirator with a full facepiece, helmet, or hood. 

Any self-contained breathing apparatus with a full facepiece. 

A Type C supplied-air respirator operated in pressure-demand or other positive 

pressure or continuous-flow mode. 

A powered air-purifying respirator with a high efficiency particulate filter. 

A Type C supplied-air respirator operated in pressure-demand or other positive 

pressure or continuous-flow mode. 

Self-contained breathing apparatus with a full facepiece operated in pressuredemand or other positive pressure mode. 

A combination respirator which includes a Type C supplied-air respirator with a 

full facepiece operated in pressure-demand or other positive pressure or continuous-flow mode and an auxiliary self-contained breathing apparatus operated in 

pressure-demand or other positive pressure mode. 

Self-contained breathing apparatus with a full facepiece operated in pressuredemand or other positive pressure mode. 

*Only NIOSH-approved or MSHA-approved equipment should be used. 

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