How to write update statement to table statusvalues where chemical id

Question

How to write update statement to table statusvalues where chemical id have more than one chemical status ?

I work on SQL server 2012 I face issue ; I can't update status on table statusvalues where chemical id have more than one status

as example

1241 must update status "chemical id have multiple status" because chemicalid have 2 status Rohs and china

1600 not update status because it have only one status as LifeCycle .

create table #chemical
(
chemicalId int,
PartId int,
chemicalStatus nvarchar(50)
)
insert into #chemical(chemicalId,PartId,chemicalStatus)
values
(1241, 2250,'Rohs'),
(1241, 2700,'Rohs'),
(1241, 2900,'China'),
(1600, 2950,'Lifecycle'),
(1600, 3000,'Lifecycle')
create table #statusvalues
(
chemicalid int,
status nvarchar(50)
)
insert into #statusvalues(chemicalid)
values
(1241),
(1600)

Expected result :

chemicalid     status
1241             chemical id have multiple status
1600             NULL