Exactly What is Personal Protective Equipment (PPE)?

Personal protective equipment includes all clothing and accessories designed to create a barrier against workplace hazards. The basic element of any personal protective equipment management program should be an in-depth evaluation of the equipment needed to protect against the hazards at the workplace.

Much of the personal protective equipment (PPE) information in this chapter is framed in general terms and is intended to complement relevant regulations and manufacturers' requirements. For more specific information, refer to the OSHA standards cited earlier.

In some instances the standards refer to specifications by:

• American National Standards Institute (ANSI)
  11 West 42 Street, 13th Floor
  New York, NY 10036

and

• American Society for Testing and Materials (ASTM)
  1916 Race Street
  Philadelphia, PA 19103

Many methods of reinforcing the use of personal protective equipment have been employed. Regardless of the method, the employee should understand at the outset that his or her life may well depend upon the use of the equipment.

Using personal protective equipment requires hazard awareness and training on the part of the user. Employees must be aware that the equipment does not eliminate the hazard. If the equipment fails, exposure will occur. To reduce the possibility of failure, equipment must be properly fitted and maintained in a clean and serviceable condition.

Selection of the proper piece of personal protective equipment for the job is important. Employers and employees must understand the equipment's purpose and its limitations. The equipment must not be altered or removed even though an employee may find it uncomfortable. (Sometimes equipment may be uncomfortable simply because it does not fit properly.) Work procedures should be instituted making it a violation (resulting in termination) to modify or refuse to wear the equipment.

Develop a Personal Protective Equipment (PPE) Program

Management dedicated to the safety and health of employees should use that evaluation to set a standard operating procedure for personnel, then train those employees to use, maintain, and clean the equipment to protect themselves against those hazards.

A written PPE program should be established for the workplace. The two basic objectives of any PPE program should be to protect the wearer from safety and health hazards, and to prevent injury to the wearer from incorrect use and/or malfunction of the PPE.

To accomplish these goals, a comprehensive PPE program should include:

• Hazard assessment of the workplace,
• Medical monitoring,
• Environmental surveillance,
• Selection, use, maintenance, and decontamination of PPE, and
• Employee training.

Program Review and Evaluation

Your PPE program should be reviewed at least annually. Elements which should be considered in the review include:

• The number of person-hours that workers wear various protective ensembles,
• Accidents and illness experience,
• Levels of exposure,
• Adequacy of equipment selection,
• Adequacy of the operational guidelines,
• Adequacy and effectiveness of training and fitting elements,
• Coordination with overall safety and health program,
• The adequacy of program records,
• Program costs, and
• Recommendation for program improvement and modification.

The results of the program evaluation should be made available to employees and presented to top management so that program adaptations may be implemented.

Hazards of Personal Protective Equipment (PPE)

While personal protective equipment is part of the job in some industries—face shields for welding—as a rule, it is considered a last-resort, temporary type of protection. For normal operations, first choice will always be given to eliminating the hazard in the environment rather than using PPE. This is called implementing engineering controls.

No single combination of protective equipment and clothing is capable of protecting against all hazards. Thus, PPE should be used in conjunction with other protective methods. The use of PPE can itself create significant worker hazards, such as heat stress, physical and psychological stress, and impaired vision, mobility, and communication.

In general, the greater the level of PPE protection, the greater are the associated risks. For any given situation, equipment and clothing should be selected that provide an adequate level of protection. Overprotection as well as under-protection can be hazardous and should be avoided.

Using PPE improperly or in a manner unsuited to its design and purpose is worse than using no protection at all. Without any protection, the worker knows he is vulnerable and perhaps, takes precautions. With some protection, the worker may rashly blunder into severe difficulty, thinking he is safe.

Personal Protective Equipment

1910.132 General Requirements

• (a) Application. Protective equipment, including personal protective equipment for eyes, face, head, and extremities, protective clothing, respiratory devices, and protective shields and barriers, shall be provided, used, and maintained in a sanitary and reliable condition wherever it is necessary by reason of hazards of processes or environment, chemical hazards, radiological hazards, or mechanical irritants encountered in a manner capable of causing injury or impairment in the function of any part of the body through absorption, inhalation or physical contact.

Under OSHA, you are required to provide a hazard-free environment for your employees. Anyone encountering hazardous conditions must be protected against the potential hazards. The purpose of personal protective clothing and equipment (PPE) is to shield or isolate individuals from the chemical, physical, and biological hazards that may be present in the workplace.

In general, it is just good common sense to have PPE available for whatever emergency situation could arise in your operation. The use of PPE is specifically required by OSHA in 29 CFR 1910, in at least the following places:

• 1910.94(a)(5) - Abrasive Blasting
• 1910.95(b)(1) - Noise Exposure
• 1910.120 - Hazardous Waste Operations and Emergency Response
• 1910.137 - Electrical Protective Equipment
• 1910.156(f) - Fire Brigades
• 1910.252(b)(2) and (3) - Welding, Cutting, and Brazing
• 1910.261(b)(2) - Pulp, Paper, and Paperboard Mills
• 1910.262(qq) - Textiles
• 1910.266(d)(1) - Logging Operations
• 1910.1000(d) - Asbestos Exposure
• 1910.1200(h)(2)(iii) - Hazard Communication Standard

Methods to Lower Workplace PELs

According to OSHA policy, engineering controls and work practices are preferred over personal protective equipment to control employee exposures to airborne contaminants.

Engineering controls involve the use of a local exhaust ventilation, general ventilation, isolation of the worker and enclosure of the source of emissions, process modifications, equipment modifications, and substitution of nonhazardous or less hazardous chemicals. These methods may be used alone or in combination, depending upon the industrial processes involved. These controls are widely used and will effectively control exposures either by themselves, or coupled with changes in work practices.

Ventilation

Perhaps the most widely used technique for controlling chemical exposure is the use of ventilation. General ventilation uses the movement of air within the general work space to displace or dilute the contaminant with fresh outside air. General ventilation may not be the preferred control method, however, due to the large volumes of air movement required. Local exhaust ventilation uses a much smaller volume of air and controls emissions at the point or source from which contaminants are generated.

Isolation

Isolation involves placing a physical barrier between the hazardous operation and the worker. Many modern, automated manufacturing processes are now fully enclosed in ventilated cabinets. The effectiveness of such a control technique depends on the frequency with which the workers have to enter the enclosure during normal operations.

In other situations, the worker, rather than the process or machine, can be placed in an enclosure having a controlled atmosphere. Many processes which involve potential chemical exposures are operated remotely by operators from air conditioned booths isolated from the hazardous materials.

Substitution

Substitution refers to the replacement of a toxic chemical in a particular process or work area with another, less toxic or non-toxic product. Properly applied, substitution can be a very effective control technique. However, care must be taken to ensure that the proposed substitute performs in a similar manner to the product being replaced. In addition, it is essential that the substitute be carefully evaluated to ensure that in controlling one hazard, another different hazard is not inadvertently introduced. The substitute must also be compatible with existing manufacturing equipment and processes.

The success of these engineering control techniques will depend on the physical properties of the chemicals and emissions encountered (boiling point, vapor pressure, etc.) and the process operating conditions. In some cases, particularly with cleaning solvents, substitution may provide the quickest and most effective means of reducing exposure. In other situations, a major effort may be required to alter processes or install or expand local or general dilution ventilation.

OSHA has found that engineering controls and improved work practices are available to reduce exposure levels to the new levels in almost all circumstances. However, in some circumstances, respiratory protection may be necessary to complement engineering controls. Respiratory protection may be necessary to achieve compliance in some specific operations in some industries.

Engineering Controls vs. Protective Equipment

So in other words, the most desirable way to deal with an air contaminant is to alter the process so that the contaminant is no longer produced. If the process cannot be changed or materials substituted, a well designed ventilation system may be the best solution to the problem. If ventilation would require too large a volume of air to reduce the concentration of the contaminant, then respiratory protection may be a necessary short-term solution.

Pitfalls of Exposure Limits

Even though you have checked the PELs and the TLVs for your chemicals, brought the exposure numbers into the acceptable range, your workers may still be endangered. How could this be?

There are over 600,000 chemicals in use today. Information available for selecting an exposure limit is very scant. Only a small percentage of chemicals is even evaluated. Therefore, supporting data can be weak. Exposure limits are changed when new information becomes available. What is considered “safe” today, may be viewed in a different light tomorrow.

Individual sensitivity is a factor. Even at an acceptable exposure level, a given chemical may have a negative effect on certain people. So even if the exposure limit protects most people, it can not be relied upon to protect everyone.

Synergistic effects should be considered. Single substances are assigned individual ratings. Seldom in the real world is only one chemical in use at a time. What happens when several chemicals combine to produce effects far more harmful than those of any one substance?

Court Decision Affecting PELs

Since the 1970s, much new information has become available which indicates that, in most cases, these early limits are outdated and insufficiently protective of worker health. To correct this situation, OSHA published a proposal in 1988 updating the air contaminant limits in general industry. When that proposal became a final rule in 1989, it lowered the existing PELs for 212 toxic air contaminants and established PELs for 164 previously unregulated air contaminants.

In July 1992, the Eleventh Circuit Court of Appeals vacated the 1989 final rule on the grounds that OSHA:

• Failed to establish that existing exposure limits in the workplace presented significant risk of material health impairment or that new standards eliminated or substantially lessened the risk; and
• Did not meet its burden of establishing that its new permissible exposure limits (PELs) were either economically or technologically feasible.

The Court’s decision to vacate the rule forced OSHA to revert back to the original protective limits. The Court granted several successive stays following the July 1992 decision, allowing the Agency time to consider further legal steps. A decision was made on March 1993 not to appeal to the Supreme Court, and the Eleventh Circuit Court’s decision stands today.

Should you comply with the 1989 PELs, even though they are no longer legally required?

OSHA believes the 1989 PELs are more protective, and encourages employers to continue compliance efforts to meet these levels, particularly where engineering and work practice controls have already been implemented. OSHA always encourages employers to go beyond the minimum protections afforded by the standards.

What are PELs and TLVs

OSHA enforces hundreds of permissible exposure limits (PELs) for toxic air contaminants found in U.S. workplaces. These PELs set enforceable limits on the magnitude and duration of employee exposure to each contaminant. The amount of exposure permitted by a given PEL depends on the toxicity and other characteristics of the particular substance. Two different types of measurement are used for PEL determination. The concentration of gases and liquids in the air is measured in parts per million (ppm). Solids and liquids in the form of mists, dusts, or fumes, are measured in milligrams per cubic meter (mg/m³).

Exposure limits called Threshold Limit Values (TLVs) were developed by the American Conference of Governmental Industral Hygienists (ACGIH). TLVs represent the level of chemicals in the ambient air that most workers can be exposed to on a daily basis without harmful effects.

OSHA’s PELs for air contaminants are located in §1910.1000, Tables Z-1, Z-2, and Z-3. The air contaminant limits were adopted by OSHA in 1971 from existing national consensus standards issued by the American Conference of Governmental Industrial Hygienists and the American National Standards Institute (ANSI). Consequently, these PELs, which have not been updated since 1971, reflect the results of research conducted in the 1950s and 1960s.

Table Z-1: Limits for Air Contaminants

Substance	CAS No. (c)	ppm (a)[a]	mg/m3(b)[a]	Skin Designation
Acetaldehyde	75-07-0	200	360
Acetic Acid	64-19-7	10	25
Acetic anhydride	108-24-7	5	20
Acetone	67-64-1	1000	2400
Acetonitrile	75-05-8	40	70
2-Acetylaminofluorine; see 1910.1014	53-96-3
Acetylene dichloride; see 1,2-Dichloroethylene.
Acetylene tetrabromide	79-27-6	1	14
Acrolein	107-02-8	0.1	0.25
Acrylamide	79-06-1		0.3	X
Acrylonitrile; see 1910.1045	107-13-1
Aldrin	309-00-2		0.25	X
Allyl alcohol	107-18-6	2	5	X
Allyl chloride	107-05-1	1	3
Allyl glycidyl ether (AGE)	106-92-3	(C)10	(C)45
Allyl propyl disulfide	2179-59-1	2	12
alpha-Alumina	1344-28-1
Total dust			15
Respirable fraction			5
Aluminum, metal (as Al)	7429-90-5
Total dust			15
Respirable fraction			5
4-Aminodiphenyl; see 1910.1011	92-67-1
2-Aminoethanol; see Ethanolamine.
2-Aminopyridine	504-29-0	0.5	2
Ammonia	7664-41-7	50	35
Ammonium sulfamate	7773-06-0
Total dust			15
Respirable fraction			5
n-Amyl acetate	628-63-7	100	525
sec-Amyl acetate	626-38-0	125	650
Aniline and homologs	62-53-3	5	19	X
Anisidine (o-, p-isomers)	29191-52-4		0.5	X
Antimony and compounds (as Sb)	7440-36-0		0.5
ANTU (alpha Naphthylthiourea)	86-88-4		0.3
Arsenic, inorganic compound (as As); see 1910.1018	7440-38-2
Arsenic, organic compounds (as As)	7440-38-2		0.5
Arsine	7784-42-1	0.05	0.2
Asbestos; see 1910.1001	([b])
Azinphos-methyl	86-50-0		0.2	X
Barium, soluble compounds (as Ba)	7440-39-3		0.5
Barium sulfate	7727-43-7
Total dust			15
Respirable Fraction			5
Benomyl	17804-35-2
Total dust			15
Respirable Fraction			5
Benzene; see 1910.1028	71-43-2
See Table Z-2 for the limits applicable in the operations or sectors excluded in 1910.1028d.
Benzidine; see 1910.1010	92-87-5
p-Benzoquinone; see Quinone
Benzo(a)pyrene; see Coal tar pitch volatiles.
Benzoyl peroxide	94-36-0		5
Benzyl chloride	100-44-7	1	5
Beryllium and beryllium compounds (as Be)	7440-41-7		([c])
Biphenyl; see Diphenyl.
Bismuth telluride, Undoped	1304-82-1
Total dust			15
Respirable fraction			5
Boron oxide	1303-86-2
Total dust			15
Boron trifluoride	7637-07-2	(C)1	(C)3
Bromine	7726-95-6	0.1	0.7
Bromoform	75-25-2	0.5	5	X
Butadiene (1,3-Butadiene); see 29 CFR 1910.1051; 29 CFR 1910.19(l)	106-99-0	1ppm/5ppm STEL
Butanethiol; see Butyl mercaptan.
2-Butanone (Methyl ethyl ketone)	78-93-3	200	590
2-Butoxyethanol	111-76-2	50	240	X
n-Butyl-acetate	123-86-4	150	710
sec-Butyl acetate	105-46-4	200	950
tert-Butyl acetate	540-88-5	200	950
n-Butyl alcohol	71-36-3	100	300
sec-Butyl alcohol	78-92-2	150	450
tert-Butyl alcohol	75-65-0	100	300
Butylamine	109-73-9	(C)5	(C)15	X
tert-Butyl chromate (as Cr03)	1189-85-1		(C)0.1	X
n-Butyl glycidyl ether (BGE)	2426-08-6	50	270
Butyl mercaptan	109-79-5	10	35
p-tert-Butyltoluene	98-51-1	10	60
Cadmium (as Cd); see 1910.1027	7440-43-9
Calcium carbonate	1317-65-3
Total dust			15
Respirable fraction			5
Calcium hydroxide	1305-62-0
Total dust			15
Respirable fraction			5
Calcium oxide	1305-78-8		5
Calcium silicate	1344-95-2
Total dust			15
Respirable fraction			5
Calcium sulfate	7778-18-9
Total dust			15
Respirable fraction			5
Camphor, synthetic	76-22-2		2
Carbaryl (Sevin)	63-25-2		5
Carbon black	1333-86-4		3.5
Carbon dioxide	124-38-9	5000	9000
Carbon disulfide	75-15-0		([c])
Carbon monoxide	630-08-0	50	55
Carbon tetrachloride	56-23-5		([c])
Cellulose	9004-34-6
Total dust			15
Respirable fraction			5
Chlordane	57-74-9		0.5	X
Chlorinated camphene	8001-35-2		0.5	X
Chlorinated diphenyl oxide	55720-99-5		0.5
Chlorine	7782-50-5	(C)1	(C)3
Chlorine dioxide	10049-04-4	0.1	0.3
Chlorine trifluoride	7790-91-2	(C)0.1	(C)0.4
Chloroacetaldehyde	107-20-0	(C)1	(C)3
a-Chloroacetophenone (Phenacylchloride)	532-27-4	0.05	0.3
Chlorobenzene	108-90-7	75	350
o-Chlorobenzylidene malononitrile	2698-41-1	0.05	0.4
Chlorobromomethane	74-97-5	200	1050
2-Chloro-1,3-butadiene; see beta-Chloroprene
Chlorodiphenyl (42% Chlorine) (PCB)	53469-21-9		1	X
Chlorodiphenyl (54% Chlorine) (PCB)	11097-69-1		0.5	X
1-Chloro-2,3-epoxypropane; see Epichlorohydrin.
2-Chloroethanol; see Ethylene chlorohydrin.
Chloroethylene; see Vinyl chloride.
Chloroform (Trichloromethane)	67-66-3	(C)50	(C)240
bis(Chloromethyl) ether; see 1910.1008	542-88-1
Chloromethyl methyl ether; see 1910.1006	107-30-2
1-Chloro-1-nitropropane	600-25-9	20	100
Chloropicrin	76-06-2	0.1	0.7
beta-Chloroprene	126-99-8	25	90	X
2-Chloro-6-(trichloromethyl) pyridine	1929-82-4
Total dust			15
Respirable fraction			5
Chromic acid and chromates (as CR03)	([b])		([c])
Chromium (II) compounds. (as CR)	7440-47-3		0.5
Chromium (III) compounds. (as CR)	7440-47-3		0.5
Chromium metal and insoluble salts (as CR)	7440-47-3		1
Chrysene; see Coal tarpitch volatiles.
Clopidol	2971-90-6
Total dust			15
Respirable fraction			5
Coal dust (less than 5% Si02), respirable fraction			([d])
Coal dust (greater than or equal to 5% Si02), respirable fraction			([d])
Coal tar pitch volatiles (benzene soluble fraction), anthracene, BaP, phenanthrene, acridine, chrysene, pyrene	65966-93-2		0.2
Cobalt metal, dust, and fume (as Co)	7440-48-4		0.1
Coke oven emissions; see 1910.1029
Copper	7440-50-8
Fume (as Cu)			0.1
Dusts and mists (as Cu)			1
Cotton duste, see 1910.1043			1
Crag herbicide (Sesone)	136-78-7
Total dust			15
Respirable fraction			5
Cresol, all isomers	1319-77-3	5	22	X
Crotonaldehyde	123-73-9; 4170-30-3	2	6
Cumene	98-82-8	50	245	X
Cyanides (as CN)	([b])		5	X
Cyclohexane	110-82-7	300	1050
Cyclohexanol	108-93-0	50	200
Cyclohexanone	108-94-1	50	200
Cyclohexene	110-83-8	300	1015
Cyclopentadiene	542-92-7	75	200
2,4-D (Dichlorophenoxyacetic acid)	94-75-7		10
Decaborane	17702-41-9	0.05	0.3	X
Demeton (Systox)	8065-48-3		0.1	X
Diacetone alcohol (4-Hydroxy-4-methyl-2-pentanone)	123-42-2	50	240
1,2-Diaminoethane; see Ethylenediamine.
Diazomethane	334-88-3	0.2	0.4
Diborane	19287-45-7	0.1	0.1
1,2-Dibromo-3-chloropropane (DBCP); see 1910.1044	96-12-8
1,2-Dibromoethane; see Ethylene dibromide.
Dibutyl phosphate	107-66-4	1	5
Dibutyl phthalate	84-74-2		5
o-Dichlorobenzene	95-50-1	(C)50	(C)300
p-Dichlorobenzene	106-46-7	75	450
3,3'-Dichlorobenzidine; see 1910.1007	91-94-1
Dichlorodifluoromethane	75-71-8	1000	4950
1,3-Dichloro-5,5-dimethyl hydantoin	118-52-5		0.2
Dichlorodiphenyltrichloroethane (DDT)	50-29-3		1	X
1,1-Dichloroethane	75-34-3	100	400
1,2-Dichloroethane; see Ethylene dichloride.
1,2-Dichloroethylene	540-59-0	200	790
Dichloroethyl ether	111-44-4	(C)15	(C)90	X
Dichloromethane; see Methylene chloride.
Dichloromonofluoromethane	75-43-4	1000	4200
1,1-Dichloro-1-nitroethane	594-72-9	(C)10	(C)60
1,2-Dichloropropane; see Propylene dichloride.
Dichlorotetrafluoroethane	76-14-2	1000	7000
Dichlorvos (DDVP)	62-73-7		1	X
Dicyclopentadienyl iron	102-54-5
Total dust			15
Respirable fraction			5
Dieldrin	60-57-1		0.25	X
Diethylamine	109-89-7	25	75
2-Diethylaminoethanol	100-37-8	10	50	X
Diethyl ether; see Ethyl ether.
Difluorodibromomethane	75-61-6	100	860
Diglycidyl ether (DGE)	2238-07-5	(C)0.5	(C)2.8
Dihydroxybenzene; see Hydroquinone.
Diisobutyl ketone	108-83-8	50	290
Diisopropylamine	108-18-9	5	20	X
4-Dimethylaminoazobenzene; see 1910.1015	60-11-7
Dimethoxymethane; see Methylal.
Dimethyl acetamide	127-19-5	10	35	X
Dimethylamine	124-40-3	10	18
Dimethylaminobenzene; see Xylidine
Dimethylaniline (N,N-Dimethylaniline)	121-69-7	5	25	X
Dimethylbenzene; see Xylene.
Dimethyl-1,2-dibromo-2,2-dichloroethyl phosphate	300-76-5		3
Dimethylformamide	68-12-2	10	30	X
2,6-Dimethyl-4-heptanone; see Diisobutyl ketone.
1,1-Dimethylhydrazine	57-14-7	0.5	1	X
Dimethylphthalate	131-11-3		5
Dimethyl sulfate	77-78-1	1	5	X
Dinitrobenzene (all isomers)			1	X
(ortho)	528-29-0
(meta)	99-65-0
(para)	100-25-4
Dinitro-o-cresol	534-52-1		0.2	X
Dinitrotoluene	25321-14-6		1.5	X
Dioxane (Diethylene dioxide)	123-91-1	100	360	X
Diphenyl (Biphenyl)	92-52-4	0.2	1
Diphenylmethane diisocyanate; see Methylene bisphenyl isocyanate.
Dipropylene glycol methyl ether	34590-94-8	100	600	X
Di-sec octyl phthalate (Di-(2-ethylhexyl)phthalate)	117-81-7		5
Emery	12415-34-8
Total dust			15
Respirable fraction			5
Endrin	72-20-8		0.1	X
Epichlorohydrin	106-89-8	5	19	X
EPN	2104-64-5		0.5	X
1,2-Epoxypropane; see Propylene oxide.
2,3-Epoxy-1-propanol; see Glycidol.
Ethanethiol; see Ethyl mercaptan.
Ethanolamine	141-43-5	3	6
2-Ethoxyethanol (Cellosolve)	110-80-5	200	740	X
2-Ethoxyethyl acetate (Cellosolve acetate)	111-15-9	100	540	X
Ethyl acetate	141-78-6	400	1400
Ethyl acrylate	140-88-5	25	100	X
Ethyl alcohol (Ethanol)	64-17-5	1000	1900
Ethylamine	75-04-7	10	18
Ethyl amyl ketone (5-Methyl-3-heptanone)	541-85-5	25	130
Ethyl benzene	100-41-4	100	435
Ethyl bromide	74-96-4	200	890
Ethyl butyl ketone (3-Heptanone)	106-35-4	50	230
Ethyl chloride	75-00-3	1000	2600
Ethyl ether	60-29-7	400	1200
Ethyl formate	109-94-4	100	300
Ethyl mercaptan	75-08-1	(C)10	(C)25
Ethyl silicate	78-10-4	100	850
Ethylene chlorohydrin	107-07-3	5	16	X
Ethylenediamine	107-15-3	10	25
Ethylene dibromide	106-93-4		([c])
Ethylene dichloride (1,2-Dichloroethane)	107-06-2		([c])
Ethylene glycol dinitrate	628-96-6	(C)0.2	(C)1	X
Ethylene glycol methyl acetate; see Methyl cellosolve acetate.
Ethyleneimine; see 1910.1012	151-56-4
Ethylene oxide; see 1910.1047	75-21-8
Ethylidene chloride; see 1,1-Dichloroethane.
N-Ethylmorpholine	100-74-3	20	94	X
Ferbam	14484-64-1
Total dust			15
Ferrovanadium dust	12604-58-9		1
Fluorides (as F)	([b])		2.5
Fluorine	7782-41-4	0.1	0.2
Fluorotrichloromethane (Trichlorofluoromethane)	75-69-4	1000	5600
Formaldehyde; see 1910.1048	50-00-0
Formic acid	64-18-6	5	9
Furfural	98-01-1	5	20	X
Furfuryl alcohol	98-00-0	50	200
Grain dust (oat, wheat, barley)			10
Glycerin (mist)	56-81-5
Total dust			15
Respirable fraction			5
Glycidol	556-52-5	50	150
Glycol monoethyl ether; see 2-Ethoxyethanol
Graphite, natural respirable dust	7782-42-5		([d])
Graphite, synthetic
Total dust			15
Respirable fraction			5
Guthion; see Azinphos methyl.
Gypsum	13397-24-5
Total dust			15
Respirable fraction			5
Hafnium	7440-58-6		0.5
Heptachlor	76-44-8		0.5	X
Heptane (n-Heptane)	142-82-5	500	2000
Hexachloroethane	67-72-1	1	10	X
Hexachloronaphthalene	1335-87-1		0.2	X
n-Hexane	110-54-3	500	1800
2-Hexanone (Methyl n-butyl ketone)	591-78-6	100	410
Hexone (Methyl isobutyl ketone)	108-10-1	100	410
sec-Hexyl acetate	108-84-9	50	300
Hydrazine	302-01-2	1	1.3	X
Hydrogen bromide	10035-10-6	3	10
Hydrogen chloride	7647-01-0	(C)5	(C)7
Hydrogen cyanide	74-90-8	10	11	X
Hydrogen fluoride (as F)	7664-39-3		([c])
Hydrogen peroxide	7722-84-1	1	1.4
Hydrogen selenide (as Se)	7783-07-5	0.05	0.2
Hydrogen sulfide	7783-06-4		([c])
Hydroquinone	123-31-9		2
Iodine	7553-56-2	(C)0.1	(C)1
Iron oxide fume	1309-37-1		10
Isoamyl acetate	123-92-2	100	525
Isoamyl alcohol (primary and secondary)	123-51-3	100	360
Isobutyl acetate	110-19-0	150	700
Isobutyl alcohol	78-83-1	100	300
Isophorone	78-59-1	25	140
Isopropyl acetate	108-21-4	250	950
Isopropyl alcohol	67-63-0	400	980
Isopropylamine	75-31-0	5	12
Isopropyl ether	108-20-3	500	2100
Isopropyl glycidyl ether (IGE)	4016-14-2	50	240
Kaolin	1332-58-7
Total dust			15
Respirable fraction			5
Ketene	463-51-4	0.5	0.9
Lead inorganic (as Pb); see 1910.1025	7439-92-1
Limestone	1317-65-3
Total dust			15
Respirable fraction			5
Lindane	58-89-9		0.5	X
Lithium hydride	7580-67-8		0.025
L.P.G. (Liquefied petroleum gas)	68476-85-7	1000	1800
Magnesite	546-93-0
Total dust			15
Respirable fraction			5
Magnesium oxide fume	1309-48-4
Total particulate			15
Malathion	121-75-5
Total dust			15	X
Maleic anhydride	108-31-6	0.25	1
Manganese compounds (as Mn)	7439-96-5		(C)5
Manganese fume (as Mn)	7439-96-5		(C)5
Marble	1317-65-3
Total dust			15
Respirable fraction			5
Mercury (aryl and inorganic) (as Hg)	7439-97-6		([c])
Mercury (organo) alkyl compounds (as Hg)	7439-97-6		([c])
Mercury (vapor) (as Hg)	7439-97-6		([c])
Mesityl oxide	141-79-7	25	100
Methanethiol; see methyl mercaptan.
Methoxychlor	72-43-5
Total dust			15
2-Methoxyethanol (Methyl cellosolve)	109-86-4	25	80	X
2-Methoxyethyl acetate (Methyl cellosolve acetate)	110-49-6	25	120	X
Methyl acetate	79-20-9	200	610
Methyl acetylene (Propyne)	74-99-7	1000	1650
Methyl acetylene-propadiene mixture (MAPP)		1000	1800
Methyl acrylate	96-33-3	10	35	X
Methylal (Dimethoxy-methane)	109-87-5	1000	3100
Methyl alcohol	67-56-1	200	260
Methylamine	74-89-5	10	12
Methyl amyl alcohol; see Methyl Isobutyl carbinol.
Methyl n-amyl ketone	110-43-0	100	465
Methyl bromide	74-83-9	(C)20	(C)80	X
Methyl butyl ketone; see 2-hexanone.
Methyl cellosolve; see 2-Methoxyethanol.
Methyl cellosolve acetate; see 2-Methoxyethyl acetate.
Methyl chloride	74-87-3		([c])
Methyl chloroform (1,1,1-Trichloroethane)	71-55-6	350	1900
Methylcyclohexane	108-87-2	500	2000
Methylcyclohexanol	25639-42-3	100	470
o-Methylcyclohexanone	583-60-8	100	460	X
Methylene chloride	75-09-2		([c])
Methyl ethyl ketone (MEK); see 2-Butanone.
Methyl formate	107-31-3	100	250
Methyl hydrazine (Monomethyl hydrazine)	60-34-4	(C)0.2	(C)0.35	X
Methyl iodide	74-88-4	5	28	X
Methyl isoamyl ketone	110-12-3	100	475
Methyl isobutyl carbinol	108-11-2	25	100	X
Methyl isobutyl ketone; see Hexone.
Methyl isocyanate	624-83-9	0.02	0.05	X
Methyl mercaptan	74-93-1	(C)10	(C)20
Methyl methacrylate	80-62-6	100	410
Methyl propyl ketone; see 2-Pentanone.
alpha-methyl styrene	98-83-9	(C)100	(C)480
Methylene bisphenyl isocyanate (MDI)	101-68-8	(C)0.02	(C)0.2
Mica; see Silicates.
Molybdenum (as Mo)	7439-98-7
Soluble compounds			5
Insoluble compounds. Total dust			15
Monomethyl aniline	100-61-8	2	9	X
Monomethyl hydrazine; see Methyl hydrazine.
Morpholine	110-91-8	20	70	X
Naphtha (Coal tar)	8030-30-6	100	400
Naphthalene	91-20-3	10	50
alpha-Naphthylamine; see 1910.1004	134-32-7
beta-Naphthylamine; see 1910.1009	91-59-8
Nickel carbonyl (as Ni)	13463-39-3	0.001	0.007
Nickel, metal and insoluble compounds (as Ni)	7440-02-0		1
Nickel, soluble compounds (as Ni)	7440-02-0		1
Nicotine	54-11-5		0.5	X
Nitric acid	7697-37-2	2	5
Nitric oxide	10102-43-9	25	30
p-Nitroaniline	100-01-6	1	6	X
Nitrobenzene	98-95-3	1	5	X
p-Nitrochlorobenzene	100-00-5		1	X
4-Nitrodiphenyl; see 1910.1003	92-93-3
Nitroethane	79-24-3	100	310
Nitrogen dioxide	10102-44-0	(C)5	(C)9
Nitrogen trifluoride	7783-54-2	10	29
Nitroglycerin	55-63-0	(C)0.2	(C)2	X
Nitromethane	75-52-5	100	250
1-Nitropropane	108-03-2	25	90
2-Nitropropane	79-46-9	25	90
N-Nitrosodimethylamine; see 1910.1016.
Nitrotoluene (all isomers)		5	30	X
o-isomer	88-72-2
m-isomer	99-08-1
p-isomer	99-99-0
Nitrotrichloromethane; see Chloropicrin.
Octachioronaphthalene	2234-13-1		0.1	X
Octane	111-65-9	500	2350
Oil mist, mineral	8012-95-1		5
Osmium tetroxide (as Os)	20816-12-0		0.002
Oxalic acid	144-62-7		1
Oxygen difluoride	7783-41-7	0.05	0.1
Ozone	10028-15-6	0.1	0.2
Paraquat, respirable dust	4685-14-7; 1910-42-5; 2074-50-2		0.5	X
Parathion	56-38-2		0.1	X
Particulates not otherwise regulated (PNOR)f.
Total dust			15
Respirable fraction			5
PCB; see Chlorodiphenyl (42% and 54% chlorine).
Pentaborane	19624-22-7	0.005	0.01
Pentachloronaphthalene	1321-64-8		0.5	X
Pentachlorophenol	87-86-5		0.5	X
Pentaerythritol	115-77-5
Total dust			15
Respirable fraction			5
Pentane	109-66-0	1000	2950
2-Pentanone (Methyl propyl ketone)	107-87-9	200	700
Perchloroethylene (Tetrachloroethylene)	127-18-4		([c])
Perchloromethyl mercaptan	594-42-3	0.1	0.8
Perchloryl fluoride	7616-94-6	3	13.5
Petroleum distillates (Naphtha) (Rubber Solvent)		500	2000
Phenol	108-95-2	5	19	X
p-Phenylene diamine	106-50-3		0.1	X
Phenyl ether, vapor	101-84-8	1	7
Phenyl ether-biphenyl mixture, vapors		1	7
Phenylethylene; see Styrene.
Phenyl glycidyl ether (PGE)	122-60-1	10	60
Phenylhydrazine	100-63-0	5	22	X
Phosdrin (Mevinphos)	7786-34-7		0.1	X
Phosgene (Carbonyl chloride)	75-44-5	0.1	0.4
Phosphine	7803-51-2	0.3	0.4
Phosphoric acid	7664-38-2		1
Phosphorus (yellow)	7723-14-0		0.1
Phosphorus pentachloride	10026-13-8		1
Phosphorus pentasulfide	1314-80-3		1
Phosphorus trichloride	7719-12-2	0.5	3
Phthalic anhydride	85-44-9	2	12
Picloram	1918-02-1
Total dust			15
Respirable fraction			5
Picric acid	88-89-1		0.1	X
Pindone (2-Pivalyl-1,3-indandione)	83-26-1		0.1
Plaster of Paris	26499-65-0
Total dust			15
Respirable fraction			5
Platinum (as Pt)	7440-06-4
Metal
Soluble salts			0.002
Portland cement	65997-15-1
Total dust			15
Respirable fraction			5
Propane	74-98-6	1000	1800
beta-Propiolactone; see 1910.1013	57-57-8
n-Propyl acetate	109-60-4	200	840
n-Propyl alcohol	71-23-8	200	500
n-Propyl nitrate	627-13-4	25	110
Propylene dichloride	78-87-5	75	350
Propylene imine	75-55-8	2	5	X
Propylene oxide	75-56-9	100	240
Propyne; see Methyl acetylene.
Pyrethrum	8003-34-7		5
Pyridine	110-86-1	5	15
Quinone	106-51-4	0.1	0.4
RDX; see Cyclonite.
Rhodium (as Rh), metal fume and insoluble compounds	7440-16-6		0.1
Rhodium (as Rh), soluble compounds	7440-16-6		0.001
Ronnel	299-84-3		15
Rotenone	83-79-4		5
Rouge
Total dust			15
Respirable fraction			5
Selenium compounds (as Se)	7782-49-2		0.2
Selenium hexafluoride (as Se)	7783-79-1	0.05	0.4
Silica, amorphous, precipitated and gel	112926-00-8		([d])
Silica, amorphous, diatomaceous earth, containing less than 1% crystalline silica.	61790-53-2		([d])
Silica, crystalline cristobalite, respirable dust	14464-46-1		([d])
Silica, crystalline quartz, respirable dust	14808-60-7		([d])
Silica, crystalline tripoli (as quartz) respirable dust	1317-95-9		([d])
Silica, crystalline tridymite, respirable dust	15468-32-3		([d])
Silica, fused, respirable dust	60676-86-0		([d])
Silicates (less than 1% crystalline silica)
Mica (respirable dust)	12001-26-2		([d])
Soapstone, total dust			([d])
Soapstone, respirable dust			([d])
Talc (containing asbestos): use asbestos limit; see 29 CFR 1910.1001.			([d])
Talc (containing no asbestos) respirable dust	14807-96-6		([d])
Tremolite, asbestiform; see 1910.1001
Silicon	7440-21-3
Total dust			15
Respirable fraction			5
Silicon carbide	409-21-2
Total dust			15
Respirable fraction			5
Silver, metal and soluble compounds (as Ag)	7440-22-4		0.01
Soapstone; see Silicates.
Sodium fluoroacetate	62-74-8		0.05	X
Sodium hydroxide	1310-73-2		2
Starch	9005-25-8
Total dust			15
Respirable fraction			5
Stibine	7803-52-3	0.1	0.5
Stoddard solvent	8052-41-3	500	2900
Strychnine	57-24-9		0.15
Styrene	100-42-5		([c])
Sucrose	57-50-1
Total dust			15
Respirable fraction			5
Sulfur dioxide	7446-09-5	5	13
Sulfur hexafluoride	2551-62-4	1000	6000
Sulfur acid	7664-93-9		1
Sulfur monochloride	10025-67-9	1	6
Sulfur pentafluoride	5714-22-7	0.025	0.25
Sulfuryl fluoride	2699-79-8	5	20
Systox, see Demeton.
2,4,5-T (2,4,5-trichlorophenoxyacetic acid)	93-76-5		10
Talc; see Silicates.
Tantalum, metal and oxide dust	7440-25-7		5
TEDP (Sulfotep)	3689-24-5		0.2	X
Tellurium and compounds (as Te)	13494-80-9		0.1
Tellurium hexafluoride (as Te)	7783-80-4	0.02	0.2
Temephos	3383-96-8
Total dust			15
Respirable fraction			5
TEPP (Tetraethyl pyrophosphate)	107-49-3		0.05	X
Terphenyls	26140-60-3	(C)1	(C)9
1,1,1,2-Tetrachloro-2,2-difluoroethane	76-11-9	500	4170
1,1,2,2-Tetrachloro-1,2-difluoroethane	76-12-0	500	4170
1,1,2,2-Tetrachloroethane	79-34-5	5	35	X
Tetrachloroethylene; see Perchloroethylene.
Tetrachloromethane; see Carbon tetrachloride.
Tetrachloronaphthalene	1335-88-2		2	X
Tetraethyl lead (as Pb)	78-00-2		0.075	X
Tetrahydrofuran	109-99-9	200	590
Tetramethyl lead, (as Pb)	75-74-1		0.075	X
Tetramethyl succinonitrile	3333-52-6	0.5	3	X
Tetranitromethane	509-14-8	1	8
Tetryl (2,4,6-TrinitrophenylmethyInitramine)	479-45-8		1.5	X
Thallium, soluble compounds (as TI)	7440-28-0		0.1	X
4,4'-Thiobis (6-tert, Butyl-m-cresol)	96-69-5
Total dust			15
Respirable fraction			5
Thiram	137-26-8		5
Tin, inorganic compounds (except oxides) (as Sn)	7440-31-5		2
Tin, organic compounds (as Sn)	7440-31-5		0.1
Titanium dioxide	13463-67-7
Total dust			15
Toluene	108-88-3		([c])
Toluene-2,4-diisocyanate (TDI)	584-84-9	(C)0.02	(C)0.14
o-Toluidine	95-53-4	5	22	X
Toxaphene; see Chlorinated camphene.
Tremolite; see Silicates.
Tributyl phosphate	126-73-8		5
1,1,1-Trichloroethane; see Methyl chloroform.
1,1,2-Trichloroethane	79-00-5	10	45	X
Trichloroethylene	79-01-6		([c])
Trichloromethane; see Chloroform.
Trichloronaphthalene	1321-65-9		5	X
1,2,3-Trichloropropane	96-18-4	50	300
1,1,2-Trichloro-1,2,2-trifluoroethane	76-13-1	1000	7600
Triethylamine	121-44-8	25	100
Trifluorobromomethane	75-63-8	1000	6100
2,4,6-Trinitrophenol; see Picric acid.
2,4,6-Trinitrophenylmethyl nitramine; see Tetryl.
2,4,6-Trinitrotoluene (TNT)	118-96-7		1.5	X
Triorthocresyl phosphate	78-30-8		0.1
Triphenyl phosphate	115-86-6		3
Turpentine	8006-64-2	100	560
Uranium (as U)	7440-61-1
Soluble compounds			0.05
Insoluble compounds			0.25
Vanadium	1314-62-1
Respirable dust (as V205)			(C)0.5
Fume (as V205)			(C)0.1
Vegetable oil mist
Total dust			15
Respirable fraction			5
Vinyl benzene; see Styrene.
Vinyl chloride; see 1910.1017	75-01-4
Vinyl cyanide; see Acrylonitrile.
Vinyl toluene	25013-15-4	100	480
Warfarin			0.1
Xylenes (o-, m-, p-isomers)	1330-20-7	100	435
Xylidine	1300-73-8	5	25	X
Yttrium	7440-65-5		1
Zinc chloride fume	7646-85-7		1
Zinc oxide fume	1314-13-2		5
Zinc oxide	1314-13-2
Total dust			15
Respirable fraction			5
Zinc stearate	557-05-1
Total dust			15
Respirable fraction			5
Zirconium compounds (as Zr)	7440-67-7		5
[a]The PELs are 8-hour TWAs unless otherwise noted; a (C) designation denotes a ceiling limit. They are to be determined from breathing-zone air samples. Parts of vapor or gas per million parts of contaminated air by volume at 25 °C and 760 torr. Milligrams of substance per cubic meter of air. When entry is in this column only, the value is exact; when listed with a ppm entry, it is approximate. The CAS number is for information only. Enforcement is based on the substance name. For an entry covering more than one metal compound measured as the metal, the CAS number for the metal is given—not CAS numbers for the individual compounds. The final benzene standard in 1910.1028 applies to all occupational exposures to benzene, except in some circumstances the distribution and sale of fuels, sealed containers and pipelines, coke production, oil and gas drilling and production, natural gas processing, and the percentage exclusion for liquid mixtures; for the excepted subsegments, the benzene limits in Table Z-2 apply. See 1910.1028 for specific circumstances. This 8-hour TWA applies to respirable dust as measured by a vertical elutriator cotton dust sampler or equivalent instrument. The time-weighted average applies to the cotton waste processing operations of waste recycling (sorting, blending, cleaning and willowing) and garnetting. See also 1910.1043 for cotton dust limits applicable to other sectors. All inert or nuisance dusts, whether mineral, inorganic, or organic, not listed specifically by substance name are covered by the Particulates Not Otherwise Regulated (PNOR) limit which is the same as the inert or nuisance dust limit of Table Z-3. [b]Varies with compound. [c]See Table Z-2. [d]See Table Z-3.

Table Z-2

Substance	8-hour time weighted average	Acceptable ceiling concentration	Acceptable maximum peak above the acceptable ceiling concentration for an 8-hour shift
			Concentration	Maximum duration
Benzene[a] Z37.40-1969	10 ppm	25 ppm	50 ppm	10 minutes.
Beryllium and beryllium compounds (Z37.29-1970)	2 μg/m3	5 μg/m3	25 μg/m3	30 minutes.
Cadmium fume[b] (Z37.5-1970)c	0.1 mg/m3	0.3 mg/m3
Cadmium dust[b] (Z37.5-1970)c	0.2 mg/m3	0.6 mg/m3
Carbon disulfide (Z37.3-1968)	20 ppm	30 ppm	100 ppm	30 minutes.
Carbon tetrachloride (Z37.17-1967)	10 ppm	25 ppm	200 ppm	5 minutes in any 4 hrs.
Chromic acid and chromates (Z37.7-1971)		1 mg/10m3
Ethylene dibromide (Z37.31-1970)	20 ppm	30 ppm	50 ppm	5 minutes.
Ethylene dichloride (Z37.21-1969)	50 ppm	100 ppm	200 ppm	5 minutes in any 3 hrs.
Fluoride as dust (Z37.28-1969)	2.5 mg/m3
Formaldehyde; see 1910.1048
Hydrogen fluoride (Z37.28-1969)	3 ppm
Hydrogen sulfide (Z37.1966)		20 ppm	50 ppm	10 mins. once, only if no other meas, exp. occurs.
Mercury (Z37.8-1971)		1 mg/10m3
Methyl chloride (Z37.18-1969)	100 ppm	200 ppm	300 ppm	5 minutes in any 3 hrs.
Methylene chloride: see §1910.1052
Organo (alkyl) mercury (Z37.30-1969)	0.01 mg/m3	0.04 mg/m3
Styrene (Z37.15-1969)	100 ppm	200 ppm	600 ppm	5 minutes in any 3 hrs.
Tetrachloroethylene (Z37.22-1967)	100 ppm	200 ppm	300 ppm	5 minutes in any 3 hrs.
Toluene (Z37.12-1967)	200 ppm	300 ppm	500 ppm	10 minutes.
Trichloroethylene (Z37.19-1967)	100 ppm	200 ppm	300 ppm	5 minutes in any 2 hrs.
[a]This standard applies to the industry segments exempt from the 1 ppm 8 hour TWA and 5 ppm STEL of the benzene standard §1910.1028. [b]This standard applies to any operations or sectors for which the Cadmium standard, 1910.1027, is stayed or otherwise not in effect.

Table Z-3: Mineral Dusts

Substance		Mppcf[a]	mg/m3
Silica:
Crystalline
Quartz (Respirable)		250[b]	10 mg/m3e
		%SiO2 + 5	%SiO2 + 2
Quartz (Total Dust)			30mg/m3
			%SiO2 + 2
Cristobalite: Use ½ the value calculated from the count or mass formulae for quartz
Tridymite: Use ½ the value calculated from the formulae for quartz
Amorphous, including natural diatomaceous earth		20	80 mg/m3
			%SiO2
Silicates (less than 1% crystalline silica):
Mica		20
Soapstone		20
Talc (non containing asbestos)		20[c]
Talc (containing asbestos). Use asbestos limit.
Tremolite (see 29 CFR 1910.1001)
Portland cement		50
Graphite (natural)		15
Coal dust:
Respirable fraction less than 5% SiO2			2.4 mg/m3e
Respirable fraction greater than 5% SiO2			10 mg/m3e
			%SiO2+2
Inert or Nuisance Dust:[d]
Respirable fraction		15	5mg/m3
Total dust		50	15mg/m3
Note  Conversion factors—mppcf × 35.3 = million particles per cubic meter = particles per c.c.
e Both concentration and percent quartz for the application of this limit are to be determined from the fraction passing a size-selector with the following characteristics:
Aerodynamic diameter (unit density sphere)	Percent passing selector
2	90
2.5	75
3.5	50
5.0	25
10	0
The measurements under this note refer to the use of an AEC (now NRC) instrument. The respirable fraction of coal dust is determined with a MRE; the figure corresponding to that of 2.4 mg/m3 in the table for coal dust is 4.5 mg/m3K.
[a]Millions of particles per cubic foot of air, based on impinger samples counted by light-field techniques. [b]The percentage of crystalline silica in the formula is the amount determined from air-borne samples, except in those instances in which other methods have been shown to be applicable. [c]Containing less than 1% quartz; if 1% quartz or more, use quartz limit. [d]All inert or nuisance dusts, whether mineral, inorganic, or organic, not listed specifically by substance name are covered by this limit, which is the same as the Particulates Not Otherwise Regulated (PNOR) limit in Table Z-1.