ASTM D1048-24

Standard Specification for Rubber Insulating Blankets

ABSTRACT
This specification covers the acceptance testing of insulating rubber blankets that are used for the personal protection of workers from accidental contact with live electrical conductors, apparatus, or circuits. Two types of blankets, differing in chemical and physical characteristics, are provided and are designated as: Type I, made from properly vulcanized high-grade cis-1,4-polyisoprene rubber compound of natural or synthetic origin that is non-resistant to ozone; and Type II, made of any elastomer or combination of elastomeric compounds that is resistant to ozone. Five classes of blankets, designated as Classes 0, 1, 2, 3, and 4, are assigned according to electrical protection characteristics. Styles of blankets are designated in accordance to construction characteristics, namely: Style A, blankets free of any reinforcements; and Style B, blankets incorporated with reinforcement(s). When evaluated in accordance with the test procedures detailed herein, the blankets shall adhere to the following property requirements: electrical properties such as phase-phase maximum use voltage, AC and DC proof-test voltages, AC and DC dielectric breakdown test voltages, and AC and DC clearances; and physical and chemical properties such as ozone resistance, moisture absorption, tensile strength, tension set, elongation, drape stiffness, flex stiffness, tear resistance, resistance to accelerated heat aging, and puncture resistance.
SCOPE
1.1 This specification covers acceptance testing of rubber insulating blankets for protection of workers from accidental contact with live electrical conductors, apparatus, or circuits.  
1.2 Two types of blankets are provided and are designated as Type I, not resistant to ozone, and Type II, and Type III ozone resistant.  
1.3 Five classes of blankets, differing in electrical characteristics, are provided and are designated as Class 0, Class 1, Class 2, Class 3, and Class 4.  
1.4 Two styles of blankets, differing in construction characteristics, are provided and are designated as Style A and Style B.  
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for information only and are not considered standard.  
1.6 The following safety hazards caveat pertains only to the test method portion, Sections 16 – 19, of this specification: This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Jan-2024
• ICS: 29.035.20 - Plastics and rubber insulating materials
• Technical Committee: F18 - Electrical Protective Equipment for Workers
• Drafting Committee: F18.25 - Insulating Cover-Up Equipment

Relations

• Replaces: ASTM D1048-22 - Standard Specification for Rubber Insulating Blankets
• Effective Date: 01-Feb-2024
• Referred By: ASTM F479-06(2022) - Standard Specification for In-Service Care of Insulating Blankets
• Effective Date: 01-Feb-2024
• Referred By: ASTM F1742-03(2020) - Standard Specification for PVC Insulating Sheeting
• Effective Date: 01-Feb-2024
• Referred By: ASTM F2320-18(2022) - Standard Specification for Rubber Insulating Sheeting
• Effective Date: 01-Feb-2024
• Referred By: ASTM F2677-08a(2024) - Standard Specification for Electrically Insulating Aprons
• Effective Date: 01-Feb-2024

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D1048 − 24
Standard Specification for
1
Rubber Insulating Blankets
This standard is issued under the fixed designation D1048; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope 2. Referenced Documents
2
1.1 This specification covers acceptance testing of rubber
2.1 ASTM Standards:
insulating blankets for protection of workers from accidental
D149 Test Method for Dielectric Breakdown Voltage and
contact with live electrical conductors, apparatus, or circuits.
Dielectric Strength of Solid Electrical Insulating Materials
at Commercial Power Frequencies
1.2 Two types of blankets are provided and are designated
D297 Test Methods for Rubber Products—Chemical Analy-
as Type I, not resistant to ozone, and Type II, and Type III
sis
ozone resistant.
D412 Test Methods for Vulcanized Rubber and Thermoplas-
1.3 Five classes of blankets, differing in electrical
tic Elastomers—Tension
characteristics, are provided and are designated as Class 0,
D518 Test Method for Rubber Deterioration—Surface
3
Class 1, Class 2, Class 3, and Class 4.
Cracking (Withdrawn 2007)
D570 Test Method for Water Absorption of Plastics
1.4 Two styles of blankets, differing in construction
D573 Test Method for Rubber—Deterioration in an Air
characteristics, are provided and are designated as Style A and
Oven
Style B.
D624 Test Method for Tear Strength of Conventional Vul-
1.5 The values stated in SI units are to be regarded as
canized Rubber and Thermoplastic Elastomers
standard. The values given in parentheses after SI units are
D1388 Test Method for Stiffness of Fabrics
provided for information only and are not considered standard.
D2865 Practice for Calibration of Standards and Equipment
1.6 The following safety hazards caveat pertains only to the
for Electrical Insulating Materials Testing
test method portion, Sections 16 – 19, of this specification: This F819 Terminology Relating to Electrical Protective Equip-
standard does not purport to address all of the safety concerns,
ment for Workers
if any, associated with its use. It is the responsibility of the user
2.2 American National Standards:
of this standard to establish appropriate safety, health, and 4
ANSI/IEEE C2 National Electrical Safety Code
environmental practices and determine the applicability of
C84.1 Electric Power Systems and Equipment—Voltage
regulatory limitations prior to use. 5
Ratings (60 Hz)
1.7 This international standard was developed in accor-
dance with internationally recognized principles on standard-
3. Terminology
ization established in the Decision on Principles for the
3.1 Definitions:
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
Standards volume information, refer to the standard’s Document Summary page on
1
This specification is under the jurisdiction of ASTM Committee F18 on the ASTM website.
3
Electrical Protective Equipment for Workers and is the direct responsibility of The last approved version of this historical standard is referenced on
Subcommittee F18.25 on Insulating Cover-Up Equipment. This standard replaces www.astm.org.
4
ANSI Standard J 6.4, which is no longer available. Available from Institute of Electrical and Electronics Engineers, Inc. (IEEE),
Current edition approved Feb. 1, 2024. Published February 2024. Originally 445 Hoes Ln., P.O. Box 1331, Piscataway, NJ 08854-1331, http://www.ieee.org.
5
approved in 1949 as D1048 – 49 T. Last previous edition approved in 2022 as Available from National Electrical Manufacturers Association (NEMA), 1300
D1048 – 22. DOI: 10.1520/D1048-24. N. 17th St., Suite 900, Arlington, VA 22209, http://www.nema.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D1048 − 24
3.1.1 beaded edge, n—a narrow border of thicker rubber 3.1.15.2 Discussion—If electrical equipment and devices
which extends completely around the outer edges of the are insulated or isolated, or both, such that the multi-phase
blanket. exposure on a grounded wye circuit is removed, then the
nominal design volt
...

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: D1048 − 22 D1048 − 24
Standard Specification for
1
Rubber Insulating Blankets
This standard is issued under the fixed designation D1048; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope
1.1 This specification covers acceptance testing of rubber insulating blankets for protection of workers from accidental contact
with live electrical conductors, apparatus, or circuits.
1.2 Two types of blankets are provided and are designated as Type I, not resistant to ozone, and Type II, resistant to ozone.and
Type III ozone resistant.
1.3 Five classes of blankets, differing in electrical characteristics, are provided and are designated as Class 0, Class 1, Class 2,
Class 3, and Class 4.
1.4 Two styles of blankets, differing in construction characteristics, are provided and are designated as Style A and Style B.
1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses after SI units are provided for
information only and are not considered standard.
1.6 The following safety hazards caveat pertains only to the test method portion, Sections 16 – 19, of this specification: This
standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user
of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory
limitations prior to use.
1.7 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2
2.1 ASTM Standards:
D149 Test Method for Dielectric Breakdown Voltage and Dielectric Strength of Solid Electrical Insulating Materials at
Commercial Power Frequencies
D297 Test Methods for Rubber Products—Chemical Analysis
D412 Test Methods for Vulcanized Rubber and Thermoplastic Elastomers—Tension
1
This specification is under the jurisdiction of ASTM Committee F18 on Electrical Protective Equipment for Workers and is the direct responsibility of Subcommittee
F18.25 on Insulating Cover-Up Equipment. This standard replaces ANSI Standard J 6.4, which is no longer available.
Current edition approved July 1, 2022Feb. 1, 2024. Published August 2022February 2024. Originally approved in 1949 as D1048 – 49 T. Last previous edition approved
in 20202022 as D1048D1048 – 22.-20. DOI: 10.1520/D1048-22.10.1520/D1048-24.
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
1

---------------------- Page: 1 ----------------------
D1048 − 24
3
D518 Test Method for Rubber Deterioration—Surface Cracking (Withdrawn 2007)
D570 Test Method for Water Absorption of Plastics
D573 Test Method for Rubber—Deterioration in an Air Oven
D624 Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomers
D1388 Test Method for Stiffness of Fabrics
D2865 Practice for Calibration of Standards and Equipment for Electrical Insulating Materials Testing
F819 Terminology Relating to Electrical Protective Equipment for Workers
2.2 American National Standards:
4
ANSI/IEEE C 2C2 National Electrical Safety Code
5
C84.1 Electric Power Systems and Equipment—Voltage Ratings (60 Hz)
3. Terminology
3.1 Definitions:
3.1.1 beaded edge, n—a narrow border of thicker rubber which extends completely around the outer edges of the blanket.
3.1.2 breakdown, n—the electrical discharge or arc occurring between the electrodes and through the equipment being tested.
3.1.3 designated person, n—an individual who is qualified by experience or training to perform an assigned task.
3.1.4 electrical testing facility, n—a location with qualified personnel, testing equipment, and procedures for the inspection and
electrical testing o
...