Isocyanates Safely - Attention all Spray Painters - How to Use by hermanos




                         HOW TO USE
    This bulletin contains health and safety information                  What are the health hazards?
for workers who use isocyanate-based paints, especially                      Breathing the aerosol of isocyanate-containing
in the motor vehicle and furniture manufacturing
                                                                          paints causes irritation of the nose, throat and lungs.
    For further technical information you should refer to                 This can happen either immediately on exposure or,
the Approved Code of Practice for the Safe Use of                         more often, later. The symptoms are a dry or sore
Isocyanates.                                                              throat, coughing, wheezing, chest tightness and/or
                                                                             Some people become ‘sensitised’ to isocyanates
Introduction                                                              after inhaling the vapour. This can happen after a
    If you are a spray painter, you need to understand                    single exposure or after exposure to isocyanates over
the health risks involved in spraying polyurethane                        many years.
paints and know how to protect yourself against                              Sensitised workers experience asthma-type
them.                                                                     symptoms whenever they are exposed to free
    You will probably be familiar with the two-pack                       isocyanates. There is no cure for this condition, and
mixes of polyurethane paints, and possibly also the                       a sensitised person has to give up working with
one-pack moisture-cured mixes. These are widely                           isocyanates permanently.
used in the automotive, furniture and other                                  This is the main health hazard you have to worry
industries because of their excellent gloss, hardness,                    about. But there are two other hazards you also
adhesion and chemical resistance.                                         have to avoid with isocyanate paints:
    This group of paints contains small quantities of                        Eye contact causes irritation; it may also cause
chemicals known as isocyanates, which are very                            severe chemical conjunctivitis.
dangerous to health, especially when they are                                Skin contact causes a mild irritation which can
applied by spraying.                                                      lead to dermatitis.
    The liquid paint which comes out of a spray gun
is in a fine mist called an aerosol. If you breathe this                  What is a safe exposure?
aerosol, the liquid isocyanate is absorbed into your
                                                                             The maximum concentration of isocyanates you
lungs, and this is when health problems can start.
                                                                          may be exposed to is set by the Occupational
    Spraying is more hazardous than other methods
                                                                          Health Advisory Committee at 70 micrograms per
of applying paint because the spray can bounce back
                                                                          cubic metre of air. This is known as the Workplace
off the object you are painting and be breathed in.

Important Note:
All the publications in the Publications Archive contain the best guidance available at the time of publishing. However, you should consider
the effect of any changes to the law since then. You should also check that the Standards referred to are still current.
                   Published by the Occupational Safety and Health Service, Department of Labour, NZ. 1989
Exposure Standard-Ceiling. Some people, how-
ever, can be sensitised at concentrations much lower
than this.
   Unfortunately, even if you are working in a
modern, well-designed spray booth with mechanical
ventilation, the concentration of isocyanates will still
be over the Workplace Exposure Standard. This is
why it is essential for you to wear a respirator.
   A disposable facemask will NOT protect you as
the aerosol particles are so small they travel through
the filter material.

Design of spray booths
   Spraying with isocyanate-containing paints must
be done in a properly designed and built spray booth
with mechanical ventilation.
                                                                  Compressed air full-face respirator Positive pressure air-fed hood
   The spray booth may be of the down draught or
cross flow type. (Details of construction and the air
movement required are given in the Approved
Code of Practice for the Safe Use of
   The ventilation system must be interlocked with
the air supply to the spray gun so that the spray gun
cannot be used unless the mechanical ventilation
system is working. The mechanical ventilation must
automatically continue after spraying until the work
area is free of all paint mist.
   No one must enter the spray booth without
wearing a respirator and protective clothing until at
least 5 minutes after spraying ceases.

Respiratory protection
   A respirator is your front line of defence against
inhaling the isocyanate aerosol. Always wear a
respirator while you are spraying in a booth, or if
someone else is spraying.
   The respirator must be either:                                 Inline filter for supplied air respirator
        A compressed air-fed, full face respirator; or
                                                                  You must wear:
        A positive pressure air-fed hood; or
                                                                      Overalls that cover your entire body;
        An air-fed ori-nasal respirator with goggles.
   The compressed air supply for the respirator must                  Gloves;
be pure, have no smell, and be filtered to remove                     Goggles, if you are wearing an ori-nasal
water, dust and oil mist.                                             respirator; and
   Always check that the visor is clean and the air                   A head covering, if the respirator does not
valves work, before you start spraying.                               cover your head. A legionnaire-type cap is
   Your air-supply unit should be fitted with an                      suitable.
alarm system to warn you whenever the pressure is                 Check the illustration to make sure you have all
not safe.                                                      the correct gear.
   It is recommended that you wear a respirator
when you use a small cabinet booth for jobs such as            Personal hygiene
spraying test samples.                                            This is important in any industry where harmful
                                                               chemicals are used.
Protective clothing                                               The basic rules are common sense:
    The purpose of protective clothing is to keep the                 Wash all splashes of paint or lacquer off your
paint spray off your hair, skin and eyes. Remember                    skin at once with soap and water. Try to
it can cause skin irritation and eye damage.                          avoid using solvents as much as possible.

       Do not keep food or eat and drink in the work
       Do not smoke in the work area, or if you
       have paint on your hands.
       If possible, shower before you change into
       your street clothes.

Applying paint by brush or roller
    Applying isocyanate-containing paint by brush,
roller or dipping is generally a lot safer than
spraying, as long as the work area is well ventilated.
If you are unsure about this, wear a positive pressure

Mixing paints
   Mixing the two-pack paints is generally a safe
operation, provided you do it in a well-ventilated
place and take care in removing the lids. If you are
in doubt about the effectiveness of the ventilation,
you must wear breathing protection. An on-nasal
respirator fitted with the appropriate canister is

Dealing with spills
   If you spill any paint or lacquer, this should be
cleaned up immediately by spreading sawdust or                  Safety gear for isocyanate-containing paints
sand over the spill. Put the collected mixture in an
outside bin. The area where the paint or lacquer spilt
can be cleaned with a solution of dilute ammonia                     Paint splash on skin
and detergent.                                                       Wash the skin with plenty of soap and water.
   If you spill paint on your overalls, they should be               Take off heavily contaminated clothing
changed for a fresh pair.                                            immediately. Get medical attention if skin
                                                                     dermatitis appears.
Sanding down                                                         If paint is swallowed
    If you are sanding down a vehicle previously                     Do not make the person vomit. If the person
painted with isocyanate-containing paints, there is no               is conscious, give them about 250 ml of milk
isocyanate hazard. This is because the old paint is                  or water to drink. Take them to hospital
fully cured and contains no free isocyanate. Wear a                  immediately. Do not give an unconscious
dust mask as you would with any sanding job.                         person anything to drink.

First aid                                                    Health checks
   If you follow the procedures in this bulletin, you           If you are spraying with polyurethane paints, you
should experience no health problems from                    should have regular health checks.
isocyanates, but you do need to know what first aid             Ask your employer to arrange for you to have a
measures to take in an emergency.                            medical check-up, at the firm’s expense, before you
                                                             start work with isocyanates. This should include a
       Coughing and breathing difficulties                   lung function test and review any chest problems you
       Get the person into fresh air and call a              may already have.
       doctor.                                                  Ask for more frequent checks if you experience:
       Paint splash in eye                                           A cough (day or night) which lasts more than
       Flush the eyes with running water or sterile                  a month; or
       water from an eye wash bottle for at least 15
       minutes, holding the eyelids apart. Obtain                    A chest illness which keeps you off work
       medical attention at once.                                    more than 2 weeks.

Your employer's responsibilities
    Your employer must instruct workers on the
hazards of working with isocyanate-containing
paints and how to use them safely.
    Your employer is also legally required to provide
all the necessary safety equipment described in this

Your responsibilities
   You have a duty to use all the safety gear your
employer provides. You owe it to yourself to
protect your health – and the job you have spent
years learning.                                             Medical check should include a lung function test


To top