GB/T 31422-2015 Personal protective equipment - General technical requirements for hearing protectors
1 Scope
This standard specifies the requirements, physical performance tests, acoustic performance tests and marking of ear-muff type protectors and ear-plug type protectors.
This standard is applicable to ear-muff type protectors and ear-plug type protectors used in the workplace.
This standard is not applicable to the acoustic performance tests of hearing protectors with holes or valves and the acoustic performance tests of hearing protectors with circuits when the circuit is in on state.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB 2811 Safety helmet
GB/T 7584.1 Acoustics - Hearing protectors - Part 1: Subjective method for the measurement of sound attenuation
GB/T 7584.2 Acoustics - Hearing protectors - Part 2: Estimation of effective A-weighted sound pressure levels when hearing protectors are worn
GB/T 7584.3 Acoustics - Hearing protectors - Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixture
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
hearing protector
protective equipment used to protect hearing and shield people from excessive noise stimulation
[GB/T 23466-2009, Definition 3.1]
3.2
ear-muff
hearing protector consisting of circumaural cups pressed or held against the head around each pinna
Note: The cup can be fixed and clamped by a headband, or by assembling on the cup supporting arm of the safety helmet.
3.3
cup
cup-shaped component which is mounted on the ear-muff headband or cup supporting arm, with certain sound insulation capacity
Note: It is usually equipped with a cushion and a liner.
3.4
cushion
deformable component fitted to the rim of the cup
Note: It usually contains a foam plastic or fluid filling to improve the comfort and fit of the ear-muff when it is worn.
3.5
liner
acoustically absorptive material contained within the cup
3.6
hygiene covers
temporary, disposable covers fitted over the cushions
Note: It is used to protect cushions from the effects of dirt, perspiration, cosmetics, etc.
3.7
safety helmet
helmets to protect the human head from injuries caused by falling objects and other specific factors, consisting of a shell, harness, chins trap and accessories
[GB 2811-2007, Definition 3.1]
3.8
cup supporting arm
arm-like structure that is connected to the outer shell of the safety helmet, and can ensure that the ear-muffs are tightly fitted around the ear by pressing the cushion via the cups
3.9
headband
semi-circular ring used to ensure that ear-muffs or ear-plugs are tightly fitted to the ear by applying a certain headband force on it
3.10
head strap
flexible strap that across the top of the head and is connected to each cup, or to the headband
Note: It is used to maintain the position of the ear-muffs in behind-the-head or under-the-chin wearing mode.
3.11
headband ear-muffs
ear-muff which is connected to the cups through a headband
3.12
ear-muffs attached to an industrial safety helmet
ear-muffs that can be attached to the safety helmets through the cup supporting arm
Note: It is usually designed with three positions: parking position, stand-by position and as-worn position.
3.13
parking position
fixed position where the cup of ear-muffs attached to an industrial safety helmet is higher than the brim of the safety helmet
3.14
stand-by position
fixed position where the cup of ear-muffs attached to an industrial safety helmet is lower than the brim of the safety helmet, and the cushion does not come into contact with the head or ears
3.15
ear-plugs
hearing protector inserted into the external auditory canal or blocking the entrance of the external auditory canal
Note: Ear-plugs inserted into the external auditory canal are called fully-inserted ear-plugs, and those blocking the entrance of the external auditory canal are called semi-inserted ear-plugs.
3.16
disposable ear-plugs
earplugs that cannot be cleaned and will be discarded after use
3.17
re-usable ear-plugs
ear-plugs that can be cleaned and reused for many times
3.18
formable ear-plugs
ear-plugs that require certain shaping operations before wearing
Note: It is also called slow-recovery ear-plug.
3.19
pre-formed ear-plugs
ear-plugs that not require shaping operations before wearing
3.20
custom moulded ear-plugs
ear-plugs made based on the moulage of the user's cavum conchae and external auditory canal
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Classification and sizing
4.1 Classification
4.2 Sizing
5 Requirements
5.1 General requirements
5.2 Technical requirements for ear-muffs
5.3 Technical requirements for ear-plugs
6 Test methods
6.1 Test flow
6.2 Specimen quantity
6.3 Test environment
6.4 Physical performance test
6.5 Acoustic performance test
7 Marking
7.1 Ear-muffs
7.2 Ear-plugs
8 Information supplied by the manufacturer
8.1 Ear-muffs
8.2 Ear-plugs
Annex A (Normative) Applicable conditions of technical requirements for hearing protectors
Annex B (Normative) Test flow
Bibliography
