Revised: 1/14/2004 UN1791, Hypochlorite solution, 8, PG III RQ component: sodium hypochlorite; RQ amount: 800 lbs

PRECAUTIONARY STATEMENTS: HAZARDS TO HUMANS 

AND DOMESTIC ANIMALS

DANGER: CORROSIVE. MAY CAUSE SEVERE SKIN 

IRRITATION OR CHEMICAL BURNS TO BROKEN SKIN. 

CAUSES EYE DAMAGE. 

Do not get in eyes, on skin or on clothing. Wear goggles or face shield and 

rubber gloves (PVC or Nitrile) when handling this product. Wash after 

handling. Avoid breathing vapors. Vacate poorly ventilated areas as soon as 

possible. Do not return until odors have dissipated.

ENVIRONMENTAL HAZARDS

This pesticide is toxic to fish and aquatic organisms. Do not discharge effluent 

containing this product into lakes, streams, ponds, estuaries, oceans, or other 

waters unless in accordance with the requirements of a National Pollutant 

Discharge Elimination System (NPDES) permit and the permitting authority has 

been notified in writing prior to discharge. Do not discharge effluent containing 

this product to sewer systems without previously notifying the local sewage 

treatment plant authority. For guidance, contact your State Water Board or 

Regional Office of the EPA.

PHYSICAL AND CHEMICAL HAZARDS

STRONG OXIDIZING AGENT: Mix only with water according to label 

directions. Mixing this product with gross filth such as feces, urine, etc., or 

with ammonia, acids, detergents or other chemicals will release hazardous gases 

irritating to eyes, lungs and mucous membranes.

STORAGE AND DISPOSAL

Store in a cool, dry area away from direct sunlight. In case of a spill, flood area 

with large quantities of water. Rinse empty container thoroughly with water 

and either return empty container thoroughly with water and either return empty 

container to manufacturer or bury in an approved landfill. Product or rinsate 

that cannot be used should be diluted with water and disposed of in a sanitary 

sewer. Wastes resulting from the use of this product may be disposed of on site 

or at an approved waste disposal facility. Do not contaminate water, food, or 

feed by storage, or disposal.

DIRECTIONS FOR USE

It is a violation of Federal Law to use this product in a manner inconsistent with 

its labeling.

NOTE: This product degrades with age. Use a chlorine test kit and increase 

dosage as necessary to obtain the required level of available chlorine.

For the control bacteria, algae and fungi, add this sodium hypochlorite solution 

to tower basin, distribution box or some other point in the system to insure 

uniform mixing.

DIRECTIONS FOR USE CONTINUED ON RIGHT SIDE PANEL

Nalco 7341

A MICROORGANISM CONTROL CHEMICAL

ACTIVE INGREDIENT:

Sodium hypochlorite..........................................................................12.5%

INERT INGREDIENTS.......................................................................87.5%

TOTAL................................................................ ...........................100.0%

EPA Reg. No. 1706-20001

EPA Est. No. 1744-NH-1 EPA Est. No. 00550-GA-001

EPA Est. No. 1706-IL-1 (BP) EPA Est. No. 00550-PA-003

EPA Est. No. 1706-PA-1 (EL) EPA Est. No. 000813-AZ-001

EPA Est. No. 1706-WA-01 (VW) EPA Est. No. 000813-CO-001

EPA Est. No. 1706-CA-01 (CR) EPA Est. No 70411-LA-1

EPA Est. No. 68708-LA-1 (ST) EPA Est. No. 10897-WA-1

Letter in () that matches first letter in batch number identifies the 

establishment number.

KEEP OUT OF REACH OF CHILDREN

DANGER

FIRST AID

ú IF IN EYES: Hold eyes open and rinse slowly and gently with 

water for 15-20 minutes. Remove contact lenses, if present, after 

the first 5 minutes, then continue rinsing. Call a poison control 

center or doctor for treatment advice.

ú IF SWALLOWED: Call a poison control center or doctor 

immediately for treatment advice. Have person sip a glass of 

water if able to swallow. Do not induce vomiting unless told by 

a poison control center or doctor. 

ú IF ON SKIN: Take off contaminated clothing. Rinse skin 

immediately with plenty of water for 15-20 minutes. Call a 

poison control center or doctor for treatment advice.

ú IF INHALED: Move person to fresh air. If person is not 

breathing, call 911 or ambulances, then give artificial 

respiration, preferably mouth-to-mouth, if possible. Call a 

poison control center or doctor for treatment advice

NOTE TO PHYSICIAN: Probable mucosal damage may 

contraindicate the use of gastric lavage. Measures against circulatory 

shock, respiratory depression and convulsion may be needed. Have 

the MSDS with you when calling a poison control center or a doctor, 

or going for treatment.

SEE LEFT SIDE PANEL FOR ADDITIONAL 

PRECAUTIONARY STATEMENTS.

Nalco Company

1601 West Diehl Road

Naperville, IL 60563-1198

EMERGENCY PHONE NO. (800) 424-9300

DIRECTIONS FOR USE (continued from left side panel):

COOLING TOWER, EVAPORATIVE CONDENSER WATER, 

AND PULP AND PAPERMILL WATER SYSTEMS

A. SLUG FEED METHOD

Initial Dose: When the system is noticeably fouled, add appropriate amount of 

NALCO 7341 per 10,000 gallons of water in the system to obtain from 5 to 10 

ppm available chlorine. Repeat until control is achieved. Badly fouled systems 

must be cleaned before treatment is begun.

Subsequent Dose: When microbial control is evident, add appropriate amount of 

NALCO 7341 per 10,000 gallons of water in the system daily, or as needed to 

maintain control and keep the chlorine residual at 1 ppm.

B. INTERMITTENT FEED METHOD

Initial Dose: When the system is noticeably fouled, add appropriate amount of 

NALCO 7341 per 10,000 gallons of water in the system to obtain 5 to 10 ppm 

available chlorine. Apply half (or 1/3, 1/4, or 1/5) of this initial dose when half 

(or 1/3, 1/4, 1/5) of the water in the system has been lost by blowdown. Badly 

fouled systems must be cleaned before treatment is begun.

Subsequent Dose: When microbial control is evident, add appropriate amount of 

NALCO 7341 per 10,000 gallons of water in the system to obtain a 1 ppm 

residual. Apply half (or 1/3, 1/4, or 1/5) of this initial dose when half (or 1/3, 

1/4, 1/5) of the water in the system has been lost by blowdown.

C. CONTINUOUS FEED METHOD

Initial Dose: When the system is noticeably fouled, add appropriate amount of 

NALCO 7341 per 10,000 gallons in the system to obtain 5 to 10 ppm available 

chlorine. Badly fouled systems must be cleaned before treatment is begun.

Subsequent Dose: Maintain this treatment level by starting a continuous feed of 

1 oz. of NALCO 7341 per 1,000 gallons of water lost by blowdown to maintain 

a 1.0 ppm residual.

TREATMENT LEVEL CHART

METHOD Ounces NALCO 

7341/10,000 Gallons Water

52-104

11

Slug Feed to obtain 5-10 ppm

Subsequent Dose to maintain 1 ppm residual

52-104

11

Intermittent Feed to obtain 5-10 ppm

Subsequent Dose to maintain 1 ppm residual

Continuous Feed to obtain 5-10 ppm 52-104

Subsequent Dose (per 1000 gallons) to 

maintain 1 ppm residual 1.0

NET CONTENTS SHOWN ELSEWHERE ON CONTAINER