Hesperian Health Guides

Hesperian Health Guides

Mercapto-based rubber accelerators

Every day 20,000 people visit the HealthWiki for lifesaving health information. If everyone gave just $5 we could translate 50 more chapters.

Make a giftMake a gift to support this essential health information people depend on.


HealthWiki > Workers' Guide to Health and Safety > APPENDIX B: Common chemicals and materials > Mercapto-based rubber accelerators


Rubber accelerators are used to make rubber material more durable and flexible. They are added to the rubber used to make shoe soles.

Accelerators that contain sulfur are called mercapto-based accelerators. Sulfur acts as a type of glue that makes the rubber more compact and keeps it from breaking easily. Rubber accelerators often come in a mix. Since there may be several mercapto-based accelerator chemicals in a mix, it can be difficult to know which chemicals are present and how much of each you are working with.

Mercapto-based rubber accelerators release very toxic fumes when they burn. Do not store these chemicals near heat or near acids.

The charts include only some of the mercapto-based rubber accelerators that exist. See Learn about chemicals used in your factory and how to find information about other accelerators. See the Index of chemical names to find alternative names for mercapto-based rubber accelerators.

Prevent or reduce exposure:

  • Use ventilation systems that extract fumes and replace or dilute dirty air with clean air (see Chapter 17: Ventilation).
  • Enclose operations where possible.
  • Wear gloves when handling rubber accelerator compounds. It is very important to avoid skin contact with these chemicals because mercaptobased rubber accelerators are known to severely irritate your skin and cause allergic reactions. Wear correct respirators that fit you (see Chapter 18: Personal protective equipment).
  • Do not mix or pour mercapto-based rubber accelerators by hand.
  • Have an emergency plan that includes first aid treatment and protective equipment for spills, splashes, and exposures. Keep necessary emergency supplies at the work site well stocked and accessible to workers.
  • Work areas where mercapto-based rubber accelerators are used, stored, and mixed need to be controlled for heat and monitored for concentration of fumes and vapors. Work areas should also have alarms, fire extinguishers, and a fire emergency plan (see Chapter 11: Fire).


Mercapto-based rubber accelerators


2-Mercaptobenzothiazole (MBT, 2-benzothiazolethiol) CAS No. 149-30-4

fire or explosive


might cause cancer



2,2-Mercaptodibenzothiazyl disulphide (MBTS, 2,2-dibenzothiazyl disulfide) CAS No. 120-78-5

fire or explosive





Zinc-2-mercaptobenzothiazole (ZMBT, bis(2-benzothiazolylthio) zinc, zinc mercaptobenzothiazole salt) CAS No. 155-04-4

fire or explosive




WHAT ARE THEY?
MBT comes in yellow crystals. MBTS and ZMBT are pale yellow powders. Mercaptobased rubber accelerators have an unpleasant, rotten-egg smell, or no smell at all. They have a bitter taste.
DO YOU WORK WITH THEM?
Mercapto-based rubber accelerators are used in rubber for shoe soles. They make natural and synthetic rubber more durable and flexible .
WHEN THEY COME IN CONTACT WITH YOUR BODY
SKIN

They irritate and burn your skin. You may develop a skin rash, redness, and dryness. Your skin might start peeling, itching, and cracking. See First Aid.

EYES

They irritate and burn your eyes. See First Aid.

NOSE/LUNGS

The dust can irritate your nose, throat, and lungs, causing sore throat, congestion, and coughing. Inhaling the dust can cause headaches and dizziness. See First Aid.

MOUTH/BELLY
They can irritate your gastrointestinal tract and cause nausea, vomiting, and diarrhea. If you swallow mercapto-based rubber accelerators, take activated charcoal with water if available. See First Aid and seek medical help.
WHEN YOU ARE EXPOSED OVER TIME:

Mercapto-based rubber accelerators can make your skin very sensitive and cause skin allergies after repeated contact. You can have a skin reaction if you come in contact with even very small amounts of these chemicals.

MBT may cause colon, bladder, and bone marrow cancer.
IF YOU ARE AT RISK OF EXPOSURE:

Use elbow-length, butyl rubber gloves, an apron, and eye/face protection (see Chapter 18: Personal protective equipment).

Use a supplied-air respirator.
SAFER SUBSTITUTES:
Benzoyl peroxide is a less harmful rubber additive than mercapto-based accelerators, but this alternative is not completely safe either.



en.hesperian.org
In other languages