This manual provides information for reducing the risks associated with the handling and storage of alpha-methlylstyrene (AMS). While it is not intended to be a comprehensive examination of all possible AMS safety issues, it does provide sufficient direction to enable individuals who manufacture, use, store, transport, dispose, recycle and/or reclaim this chemical to do so properly.

AMS is used in the manufacture of certain plasticizers, resins, and in polymerization production processes (i.e., acrylonitrile butadiene styrene (ABS) used extensively in the automotive industry.

AMS is a water white liquid possessing a sharp, aromatic odor. It has a flash point of 118° F (47.8°C). It's vapors form flammable mixtures with air and may travel considerable distance to a source of ignition and flash back. AMS is a fire hazard when exposed to heat, sparks, or flames. Fire may produce irritating or poisonous gases. AMS is an irritant to the eyes, skin and upper respiratory tract.

USE OF THIS DOCUMENT

Alpha-Methylstyrene (AMS) should always be handled, stored and used with precautions against fire and explosion. It is a flammable liquid and can form flammable mixtures with air. Open flames, local hot spots, friction, static electricity and all other sources of ignition are to be avoided when working with this material.

Appropriate safety gear should be worn while handling alpha-methylstyrene. This includes safety glasses with cup-type side shields or chemical goggles, safety shoes, natural rubber gloves, and hard hat. In unusual or emergency situations when contact with the liquid is necessary or likely, the handler should wear full protective clothing and equipment. All contaminated clothing must be washed before reuse.

In case of eye contact with alpha-methylstyrene, wash with copious amounts of water for at least 15 minutes. Safety showers and eye-wash stations should be located near the hazard. Obtain medical attention promptly. If inhaled, remove the patient from the contaminated atmosphere to fresh air. If not breathing, give artificial respiration, preferably mouth-to-mouth. If breathing is difficult, give oxygen which is administered only by trained personnel. Get prompt medical attention.

For more detailed information on first aid and the safe handling of AMS, refer to the Material Safety Data Sheet which can be provided to you by Sunoco, Inc. in compliance with OSHA's Hazard Communication regulation.

SPECIAL FIRE FIGHTING PRECAUTIONS: Handle as a flammable liquid . Use a water spray to keep fire-exposed tanks and containers cool. Do not enter the fire area without proper personal protective equipment, including a self-contained breathing apparatus. Beware: Vapor is heavier than air and may travel (i.e. crawl along the ground to a source of ignition and flash back. 

For the safe storage of alpha-methylstyrene (AMS), portable tanks not exceeding 660 gallons and containers not exceeding 60 gallons must comply with the National Fire Protection Association (NFPA) Code 30, Chapter 4 and the Occupational Safety and Health Administration (OSHA) regulation 1910.106. Leaks are difficult to detect in underground tanks but if it is necessary to use such tanks, they must also conform to the above mentioned codes and all federal, state and local regulations.

The design of storage tanks must conform to the principles of good engineering practice. Bulk storage tanks for AMS may be located either inside or outside of buildings. If stored indoors, buildings must conform to appropriate codes including OSHA, NFPA and all federal, state and local regulations. Similarly, outside storage tanks must be located at minimum distances from property lines and right of ways consistent with the above codes and all federal, state and local regulations. Tanks can be either horizontal or vertical and in any shape consistent with good design principles. AMS can be stored in tanks designed for the following pressure ranges and standards:

Pressure tanks built according to ASME code are preferred over atmospheric tanks if AMS is to be stored at or near its boiling point 329 degrees F (165°C). Normally bulk storage will be done at ambient conditions. If it becomes necessary to store AMS such that its vapor pressure will exceed 0.75 PSIA, Federal regulations require either a floating roof tank or a vapor recovery system. If the tank exceeds 40,000 gallons capacity the vapor pressure limit is 4.0 PSIA. To maintain AMS quality, it is recommended that the AMS storage temperature does not exceed 86° F (30°C).

In the case of atmospheric tanks, provision must be made for inbreathing (vacuum relief) and outbreathing (pressure relief) in the form of a combination pressure/ relief valve sized according to the vent rates established by NFPA 30, Flammable & Combustible Liquid Code.

Vents are to be sized so that the tank does not exceed its maximum allowable working pressure. For most tanks, emergency vents are required to protect against fire exposure. These vents are normally sized for 2.5 PSIG. Although protection can be achieved by use of additional P/V valves, a gauge hatch or manhole cover that lifts when exposed to abnormal pressure is normally used. Local environmental considerations and regulations may require more extensive venting systems than those near the top of the fill line to prevent backflow of AMS through the fill line.

All storage tank systems should be equipped with instrumentation to monitor temperature and level, as well as high level alarm if possible. Tank levels can be measured accurately with float type devices.

Valves and piping should have standard flanged connections. Fire safe valves, which can be plug, gate, ball, or others capable of providing tight shut-off and consistent with ANSI Standard B31.3 or ANSI B31.4, should be used whenever possible. Plastic valves should be avoided since they typically do not provide adequate fire protection. Sufficient valves are required to control flow into and discharge from the tanks under normal and emergency conditions. Centrifugal or positive displacement pumps may be used to transfer AMS with appropriate guards installed to prevent spray in case of leakage.

Electrical equipment should meet the requirements of NEC (NFPA 70). Additional information can be found in NFPA 30, The Flammable & Combustible Liquids code and NFPA 497A, Recommended Locations for Electrical Installation Chemical Process Areas, 1992, which gives the minimum requirements for proper classification.

In dealing with static electricity problems, refer to NFPA 77, Recommended Practice on Static Electricity, 1993 and NFPA70, Lightning Protection Code, 1992. In order to minimize problems from static electricity arising from the loading or unloading of alpha-methylstyrene, grounding and bonding procedures should be used. (Refer to NFPA 77).

Locations of tanks with respect to each other and property lines need to conform with NFPA 30. Provisions for containment of spills from tanks must also be made in accordance with this standard.

Carbon steel or stainless steel are the preferred materials for construction of tanks, pumps & piping components.

Copper and copper containing alloys should not be used for AMS storage since prolonged contact causes a blue-green color in the material.

Wood or glass should not be used as materials of construction. Rubber hoses should be avoided since AMS is a solvent for natural and synthetic rubbers. Neoprene is acceptable as well as flexible metal hoses.

Gaskets may be Teflon reinforced with stainless steel.

If there is uncertainty about AMS compatibility with a particular material, the manufacturer or other reputable sources should be consulted.

Guidelines for loading and unloading bulk deliveries are covered in NFPA 30, 1993, Chapter 5. Systems must also comply with DOT Regulation 40 CFR 172.312 and 49 CFR 172.402.

Tank trucks and cars should be inspected for leaks as they enter the plant. If any leaks occur during the operation, flow should be halted immediately and response action taken. Any spilled material must be prevented from entering city sewers or natural waterways. The collected waste should be disposed of in a proper waste recovery system. Appropriate Federal, State, and Local Regulatory Authorities should be contacted before discharge, treatment or disposal of waste material.

Proper product information and danger signs should be posted during the transfer operation. Care should be taken when unloading a bulk delivery to insure that the tank has sufficient empty capacity to handle the contents of the tank car or truck. Verify that the storage tank is properly vented before filling is begun.

It is desirable that facilities for handling tank cars and tank trucks be in an adequately contained area.

In preparation for unloading, vent the top of the tank car or truck. Appropriate safety gear should be worn during this operation. Personnel should remain close by during loading and unloading operations and be ready to halt material transfer if problems arise.

Air pressure should not be used to unload bulk deliveries.

The volatile properties of AMS make maintenance and inspection procedures especially critical. Personnel should continuously be alert for possible leaks from valves, pump fittings, and storage tanks. Inspect all atmospheric tanks internally ever 5 years or when operational problems arise. Annually compare ultrasonic measurements of tank material thickness to monitor its corrosion rate conducting a visual inspection of all welds at this time. If potential problem areas are observed, than an x-ray inspection should follow and repairs made accordingly.

Specific maintenance procedures for other equipment are available from its manufacturer. Testing of all systems must be in accordance with applicable codes.