Los Angeles County Municipal Code Part 9 Vapor Degreasers Using Chlorinated Solvents

A.

Degreasing tanks with an open surface area in excess of 600 square inches shall be located in a room with a volume of at least 8,000 cubic feet, or the room or degreasing tank shall be provided with mechanical exhaust ventilation.

B.

Tanks shall be located so that drafts from nearby doors, spray booths, other ventilated equipment, windows and moving equipment will not disturb the solvent vapors. Where there are extreme drafts across the degreaser, the tank shall be baffled in a manner which will eliminate such cross-drafts.

C.

The tank shall be located at least 25 feet from an open flame, electric arcs or red-hot metals.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1183, 1959.)

A.

Work baskets, racks and the method of handling materials shall be such as to minimize dragout of liquid or vapor solvent. Racks or slings shall not be constructed of porous materials, such as wood or rope.

B.

Vertical speed of hoist movement shall not exceed 11 feet per minute.

C.

The freeboard shall be at least one-half the tank width. All tanks which are used only intermittently or occasionally shall be provided with a sliding or rolling cover.

D.

Both boiling solvent and vapor zones shall be thermostatically controlled, with manual reset for the heat supply.

E.

Where low-flashpoint contaminants are being removed by vapor degreasing, the thermostat shall be set with due regard to the flashpoint characteristics of the contaminant-solvent mixture.

F.

The thermostat in the freeboard area shall be set at a maximum of 165 degrees Fahrenheit for trichloroethylene and 230 degrees Fahrenheit for perchloroethylene.

G.

Degreasers shall be equipped with an adequate condenser system to control the vapor level.

H.

The condenser system shall be regulated so as to provide an outlet water temperature of not less than 100 degrees Fahrenheit or more than 130 degrees Fahrenheit.

I.

A water separator shall be installed in machines having an open surface area greater than 300 square inches.

J.

Gas-heated combustion chambers shall be vented to the outside atmosphere.

K.

A back-draft diverter shall be installed on the vent pipe to insure a positive draft.

L.

There shall be a sump drain at the lowest point of the tank for solvent and sludge removal.

M.

Where equipment is of sufficient size to require entrance of personnel for cleaning, a side cleanout door shall be provided for the purpose of scraping out sludge.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1184, 1959.)

A.

Clear, concise, step-by-step instructions for proper operation of the degreaser shall be placed in a conspicuous location on or near the degreaser.

B.

All degreaser operators shall be taught to operate equipment according to proper operating instructions.

C.

Only the solvent for which the unit is designed shall be used.

D.

Solvent must have an inhibitor to prevent decomposition due to high temperature, light, or catalytic agents.

E.

The level of the boiling solvent shall never be allowed to drop below the top of the heating surfaces.

F.

Work shall be held in the vapor zone until it has reached the vapor temperature as evidenced by the stopping of condensation.

G.

The spray nozzle shall be kept well below the vapor level zone at all times during use of spray.

H.

Covers shall be closed when a degreaser is not in use, whether the machine is cold or in a standby condition.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1185, 1959.)

Welding shall not be attempted on or near any part of a degreaser until all solvent liquid has been removed and the machine thoroughly ventilated.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1188, 1959.)

A.

Local exhaust ventilation shall be provided on tanks which are wider than 3.5 feet and on any other tank where the design, method of operation or location results in workers being exposed to more than the threshold limit value.

B.

Where exhaust ventilation is used, a slot-type exhaust shall be installed.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1189, 1959.)

Where general exhaust ventilation does not adequately remove noxious solvent vapors, local mechanical exhaust shall be provided.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1190, 1959.)

A.

When temperature of the boiling liquid reaches 195 degrees Fahrenheit for trichloroethylene and 250 degrees Fahrenheit for perchloroethylene, the employer shall clean out the degreaser.

B.

Tank cleaning operations shall be done during periods when a minimum number of employees are in the area.

C.

Tanks should not be entered unless absolutely necessary. If entry is necessary, the following steps shall be taken:

Remove all solvent from the tank;

Remove all sludge after it has cooled to below 180 degrees Fahrenheit;

Aerate the tank to remove residual solvent.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1186, 1959.)

A.

The pit shall be aerated for a long enough period to insure safe conditions before entering.

B.

Positive ventilation shall be provided while the man is in the pit.

(Ord. 8588 § 9 (part), 1964; Ord. 7583 Part 3 Ch. 16 § 1187, 1959.)